zek HYDRO 2015 by zek Magazin

Verlagspostamt: 4820 Bad Ischl · P.b.b. „03Z035382 M“ – 13. Jahrgang

zek HYDRO 2015

2015 INTERNATIONAL HYDRO

FUTURE TECHNOLOGY

CompaCt Hydro Global supplier of electromechanical equipment for compact hydro power plants Photo credits: Limmatkraftwerke AG

HYDRO

Since more than 30 years aNdrItZ

Every month 11 COMPACT HYDRO plants

Hydro supplies equipment for small

are put into operation. Our COMPACT

hydropower plants up to 30 mW under

HYDRO program combines environmen-

the name of CompaCt Hydro. The

tal friendliness with high efficiency of the

small hydro market is an essential field

system.

of business for ANDRITZ HYDRO. More than 3,000 units with a total capacity of

We focus on the best solution – from

9,300 MW have been installed until today.

water to wire.

aNdrItZ Hydro GmbH Eibesbrunnergasse 20, 1120 Wien, Österreich Tel.: +43 50805 0, Fax: +43 50805 51015 contact-hydro@andritz.com

www.andritz.com

Power play.

GRP pipework systems for hydropower facilities Flowtite pipes are manufactured from glass-fibre reinforced polyester resin (or GRP for short). GRP has very low weight but is extremely durable and remarkably flexible. Flowtite pipework is suitable for all kinds or pressurised and unpressurised applications where traditional methods used piping made from cast iron, steel, ferroconcrete or stoneware. Some key benefits of pipework systems made from GPR: • Variable diameter, from DN 100 to DN 4000 • High pressure resistance, up to 32 bar • Flexible length (standard lengths are 3, 6 and 12 m)

Germany / South East Europe / Benelux:

Amiantit Germany GmbH info-de@amiantit.eu · www.amiantit.eu Austria:

ETERTEC GmbH & Co.KG oﬃce@etertec.at www.etertec.at Switzerland:

APR (Schweiz) AG info@apr-schweiz.ch www.apr-schweiz.ch Amiantit Germany GmbH · Am Fuchsloch 19 · 04720 Mochau · Tel.: + 49 34 31 71 82 - 0 · info-de@amiantit.eu · www.amiantit.eu · Member of the AMIANTIT Group

Troyer offers high-quality construction of water turbines and hydroelectric power plants. For generations, our tailor-made solutions have helped our customers optimizing energy generation from waterpower in a safe, efficient, eco-friendly and sustainable way. Troyer SpA info@troyer.it Tel. +39 0472 765 195

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QUO VADIS SMALL-SCALE HYDROPOWER? Many developments in the last few years have affected the status and development of small-scale hydropower. First, the Water Framework Directive raised concerns among many small-scale hydropower operators. The directive demanded an improvement of the fish passage facilities and an increase in the residual flow. This has resulted in financial burdens for many aged power plants. The situation worsened when electricity prices remained at a constant low on the international electricity markets. The reasons for this situation are as follows: the emissions trading system is still not working. The price for carbon credits is still too low, making fossil energy suppliers, such as lignite power plants, grotesquely competitive. It speaks for itself that in 2014 Germany has produced more energy from lignite than in any other year after World War II. Furthermore the support for solar and wind energy – especially in Germany – has supplied the grids with electricity from renewable resources. All this keeps electricity rates down. The negative sides of increasing electricity production from solar and wind energy also have an effect on hydropower. The strongly volatile energy types, which depend heavily on the availability of wind and sun, and the resulting deviations in output are cause for great concern for the suppliers. In this respect energy experts always emphasize the significance of hydropower, which is able to provide base load power on the one hand and to supply balancing energy through pumped-storage power plants on the other. Despite the important role that hydropower plays, its political lobby – supporting small-scale as well as large-scale operations – is hardly noticeable. It is a different lobby that leaves its mark on current developments: only recently have nuclear energy advocates scored an unbelievable coup in the EU. The British government has received the EU's approval to build the Hinkley Point nuclear power station despite Fukushima, despite Chernobyl and despite the project's astronomical costs. The current rate for one kilowatt-hour is EUR 10,000, making the power station one of the most expensive in the world. These costs will get passed on to the taxpayers. In the next 35 years about EUR 35 billion will go to nuclear lobby groups. Experts of the Vienna University of Technology TU Wien have calculated that an additional 37 percent of green electricity from renewable resources could be produced with the same amount of subsidies. Another alarming tendency is that an additional five EU-countries are signalizing their intention to follow Great Britain's lead. The hydropower engineering company Voith Hydro conducted a survey among 600 energy experts from Austria, Germany, Switzerland, Sweden and Norway on this topic. The results showed that hydropower still has a positive image: it was listed as number one resource, with photovoltaics coming in second. According to the survey the experts all agreed that hydropower receives too little support from the political scene. Let's hope that this changes soon. In this edition of zek HYDRO international we present some selected projects and examples of today's technology, which in the last year have caused a stir in the hydropower world. The majority of the showcase power plants here presented demonstrate the leading position of Central European hydropower companies, which are preserving the long tradition of European hydropower technology on the international hydropower market. Finally, I would like to thank all those who have contributed to the production of this edition of zek HYDRO – above all our lady in the office, Erika Gallent, whose excellent work coordinating the translations was the key to our being able to release this publication on schedule. I wish all our valued readers an enjoyable and informative time reading the latest edition of zek HYDRO Best regards, Roland Gruber, Editor-in-Chief

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Since 50 years we have been developing efďŹ cient and sustainable technologies for producing energy from hydropower while stressing innovation and workmanship in the manufacture of our systems. More information at www.elektroanlagen.at www.elektroanlagen.at

WATER FLOWS CONSTANTLY ONWARDS. OUR TECHNOLOGY TOO.

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17 DOLGARROG HEPP (UK) 28 SHORT CUTS 08

03 06 08

short news out of the world of hydropower

Editorial Table of Content Masthead

May 2015

SHYPOT II HEPP (UA)

36 ROSS HEPP (CL)

38 LIXHE HEPP (B)

Austrian Turbine Manufacturer displays Core Competencies [ WALES ]

Turbine Replacement enhances Versatility of big Power Station [ BELGIUM ]

Siemens supplies and installs Small-Scale Hydro Power Station [ NORWAY ]

Textile manufacturer power plant shines in new splendour [ SWITZERLAND ]

City of Feldkirch brings ecological Model Facility to the Grid [ AUSTRIA ]

Tyrolean Region opts for collective Hydro Power Initiative [ AUSTRIA ]

Hydro Steel Engineering Specialist provides the Equipment [ AUSTRIA ]

Works on Weinzödl Power Plant complete [ AUSTRIA ]

South Tyrolean Hydro Power Technology scores in Ukraine [ UKRAINE ]

Hydro Power Turbine provides Benefits for Gas Power Station [ TURKEY ]

Turrachbach Power Plant impresses with Sustainability [ AUSTRIA ]

Water-saving Twin Lock in Münster completed [ GERMANY ]

Power Station invests Millions in environmental improvements [ GERMANY ]

Baden Operators upgrade by diving down [ GERMANY ]

Austrian Hydro Power Specialist strengthens his market position [ SRI LANKA ]

Power plants in Bogotá replace pressure reduction valves [ COLOMBIA ]

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BANDIRMA HEPP (TR)

FORSTAUBACH HEPP (A)

Ductile Iron Pipes - Backbone of drinking Water Power Plants [ TECHNOLOGY ]

Pipeline successfully laid for the Forstaubach Power Plant [ AUSTRIA ]

Refurbishment of the Malgovert Power Plant Penstock [ FRANCE ]

Braun’s Trash Rack Cleaners perform well around the world [ TECHNOLOGY ]

South Tyrolean Hydraulic Steel Engineers meet all Needs [ TECHNOLOGY ] Drum Screens make Power Plant Operators’ Hearts beat faster [ TECHNOLOGY ]

GENERATOR TECHNOLOGY

Rubber Dams provide an interesting Alternative [ TECHNOLOGY ] Through Love of Innovation to Market Leadership [ TECHNOLOGY ] Nepal’s needed Electricity Transition towards more Hydropower [ NEPAL ] RENEXPO HYDRO establishes itself in the heart of Europe [ EVENT ] RENEXPO HYDRO establishes itself in the heart of Europe [ TECHNOLOGY ]

NEPAL HYDROPOWER

Advertisers zek HYDRO 2015 Schubert

Opener

Amiantit

Troyer

Andritz Hydro

BHM-Ing.

Bilfinger VAM

Braun

Danner

Elin

Geppert

Global Hydro Energy

Gufler Metall

Gugler Water Turbines

Hitzinger

HSR Rapperswil

Hutarew

Hydro-Construct

Indar

Koncar

Kössler

Success for Austrian mechanical engineering supplier [ TECHNOLOGY ] Desander Systems for Hydro Power Plants - State of the Art [ TECHNOLOGY ]

Künz

Lukas

Muhr

Ossberger

Premel

Renexpo

Siemens

TRM Tiroler Rohre

Wiegert & Bähr

Wild Metal

WKV

May 2015

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MARGARITZE DAM: DIVING IN THE WINTER AT 2000 METRES ABOVE SEA LEVEL The Margaritze dam belongs to the Kaprun works group and every 10 years the abovewater structures and below-water parts of the plant have to be subjected. Inspection work is carried out in the winter due to the vastly superior underwater visibility at this time of year. The low temperature of the water, being closed in by an ice ceiling and the general altitude of the plant make this a challenging work – even for experienced professional divers. A hole was cut into the ice, which was roughly 50cm thick, to enable diving work to begin. The main focus of the inspection was on the integrity of the concrete, the functioning of the bottom outlet and the debris intake grates.

Masthead PUBLISHERS Mag. Roland Gruber and Günter Seefried PUBLISHING HOUSE Gruber-Seefried-Zek Verlags OG Lindaustraße 10, 4820 Bad Ischl Tel. & Fax +43 (0) 6247- 84 726 office@zekmagazin.at www.zek.at EDITOR-IN-CHIEF Mag. Roland Gruber, rg@zekmagazin.at Mobile +43 (0)664-115 05 70

photo credits: TU Vienna

Dr. Eduard Doujak is considered to be the driving force behind “Viennnahydro”. Laxenburg Castle near Vienna offers a unique ambience for the hydropower event traditionally held here every year.

EDITOR DI (FH) David Tscholl, dt@zekmagazin.at Mobil +43 (0) 664-240 67 74 MAG. Andreas Pointinger, ap@zekmagazin.at Mobil +43 (0) 664-228 23 23 MARKETING Günter Seefried, gs@zekmagazin.at Mobile +43 (0)664-3000 393 ADMINISTRATION Erika Gallent, office@zekmagazin.at Mobile +43 (0)664-242 62 22 TRANSLATION Crossing Paths Communications Mag. Andreas Florian andreas@crossing-paths.net Reinhard Ficher, BA +43-650-6130180 Roger Lord roger@roger-lord.at photo credits: Verbund/W. Syrowatka

VIENNAHYDRO 2014 GETS TO THE BOTTOM OF FUTURE HYDROPOWER TRENDS Viennahydro, traditionally held at the venerable halls of Laxenburg Castle, is one of the most established and renowned international events in the hydropower industry. This reputation was confirmed at the most recent (eighteenth) edition of the event, which took place just outside Vienna from November 26–28 last year. The event was centred around key topics such as different aspects of pumped storage, which is still considered the most effective, most tried and tested methods of storing energy. Visitors were treated to two social side events: an exclusive evening event at the Vienna Museum of Technology, and the almost traditional dinner at the “Heurigen” wine pub in Neustift. Around 300 guests had followed the invitation of Dr. Eduard Doujak and his organising team to attend the forum of experts and discuss key issues, get the latest information, exchange ideas – and, last but not least, to meet new contacts and enjoy the evening in the company of existing ones. Same as in the previous years, the comprehensive schedule of lectures and presentations was organised across three halls, with the large theatre hall providing the largest seating capacity.

photo credits: TU Vienna

HYDRO

All the parts of the plant were in good working order and complete safety can still be guaranteed.

PRODUCTION, PDF CREATION MEDIA DESIGN: RIZNER.AT Stabauergasse 5, 5020 Salzburg Tel. +43 (0) 662 / 87 46 74 E-Mail: m.maier@rizner.at PRINTING Druckerei Roser Mayrwiesstraße 23, 5300 Hallwang /Salzburg Tel. +43 (0) 662-661737 POST OFFICE A-4820 Bad Ischl BASIC GUIDELINES zek HYDRO is a non-partisan trade publication focussing on hydropower. PRICE INC. POSTAGE € 16,– / copy inc. VAT zek HYDRO is published annually Circulation: 5,400 copies

May 2015

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Desan nder Plants: Engineering, patented sluicing system HSR, Ă&#x20AC;XVKLQJ IHHGHU VHGLPHQW JDXJLQJ VWLOOLQJ UDFNV water discharge facilities 53 premium i performance f sluice l i systems t i Switzerland, in S it l d It Italy l and d Austria A t i â&#x20AC;&#x201C; iin operation/ ti / under d construction t ti

May 2015

The runner on its way from Manaus to Belo Monte.

320-TONNE RUNNER ON ITS WAY TO BELO MONTE At the beginning of this year, the largest runner Voith Hydro has ever manufactured in Latin America began its journey to hydropower plant Belo Monte in Brazil. A twelve-axle heavy-haulage vehicle collected the huge runner (5 m high, 8.5 m in diameter) from the Voith manufacturing facilities in Manaus (Brazil) and transported it around 20 km to an inland port. Lifted aboard by a heavy-duty cargo crane, it then began its 850 km journey downriver to the port of VitĂłria do Xingu in the Brazilian state of ParĂĄ. HPP Belo Monte on the Xingu river is still under construction and is scheduled to go on-line in 2019with a capacity of 11,233 MW. Voith will deliver four Francis turbines and four generators, as well as the electrical and mechanical balance-of-plant equipment and automation components. The entire engineering will also be provided by Voith

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COSTA RICA LEADING THE WAY IN RENEWABLES In their online edition, eco-magazine â&#x20AC;&#x153;Diario Ecologicaâ&#x20AC;? reported that as of the beginning of this year, Costa Rica has been meeting 99.4% of its energy needs from renewable energy sources. The largest share of clean energy (68%) is generated from hydropower, followed by geothermal, wind power, biomass, and solar energy. This was possible because of the particularly heavy rainfall in the previous months, which filled up the power stationsâ&#x20AC;&#x2122; water reservoirs. This allows the Central American countryâ&#x20AC;&#x2122;s hydropower facilities to operate at full capacity, according to the Costa Rican National Institute for Electricity. Thanks to the resulting oversupply in eco-power, electricity prices fell by 12%. Originally, it was expected that the governmentâ&#x20AC;&#x2122;s objective of meeting 100% of the countryâ&#x20AC;&#x2122;s energy needs from renewable sources would be reached in 2021. No other country in Latin America has achieved this goal so far.

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With reservoirs full to the brim, Costa Rica is able to make full use of its hydropower capacities.

Training courses: Operative O ti managementt and d maintenance i t Steel construction in hydro-power hydro power (sealing units, nits high press pressure re pipelines pipelines, rack cleaning ma achines)

The Power Plant Ins stitute Independent ndent State of the art â&#x20AC;&#x201C; Expert â&#x20AC;&#x201C; Indepe 'HYHORSPHQW

photo credits: Voith

Institut fĂźr Anlagen- und Sicherheitstechnik Prof. JĂźrg Mei e er sitec@hsr.ch Oberseestrass s e 10 CH-8640 Rapp perswil T ++41 (0)55 222 43 51 www.sitec..hsr.ch

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photo credits: Uwe Schlick / pixelio.de

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HYDRO

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BOUDRY POWER PLANT STARTS OPERATING Following one year of construction, Solutions Renouvelables Boudry SA is starting to operate the Boudry hydroelectric power plant. The power plant utilises the almost five metre drop of the Areuse, which flows out of the Val de Travers through the imposing Gorges de l'Areuse on into Lake Neuchâtel. With an output of 495 kW, the plant produces 1,650 MWh, which is equivalent to the electricity demand of around 450 households. A new fish ladder with 23 pools allows fish to ascend and descend, in particular the endangered brown trout. The construction works were closely monitored by the fisheries inspector and the local cantonal officials. The total costs amount to 4.7 million CHF. The owner and operator of the plant is Solutions Renouvelables Boudry SA, in which the council and community of Boudry have a 51 percent stake and BKW has a 49 percent stake.

photo credits: R_by_Vain / pixelio.de

HYDRO

A view of the famous Areuse Gorge. Some of its water is used for the new Boudry power plant.

The alpine water reservoir had its plug pulled – quite literally.

graphic credits: Andritz

ANDRITZ TO SUPPLY TIDAL CURRENT TURBINES TO SCOTLAND ANDRITZ HYDRO Hammerfest, part of international technology Group ANDRITZ, has received an order from MeyGen Ltd. to supply three 1.5-megawatt tidal current turbines to the planned tidal array in the Inner Sound of the Pentland Firth, Scotland. Tidal current turbines are anchored to the sea bed in coastal waters and driven by rising and falling tides. Commissioning of the three turbines is scheduled for the end of 2016. The order placed with ANDRITZ HYDRO Hammerfest is the first commercial order worldwide to supply tidal current turbines and part of the first project phase in completion of the MeyGen tidal array, which is the largest development project worldwide for a tidal turbine array. In the long-term, MeyGen is planning to install a total of 269 turbines with an overall output of 398 megawatts, which will provide predictable, renewable, and sustainable energy for 175,000 Scottish households.

When the power plant was being planned and implemented, particular consideration was given to ecological concerns due to the sensitive location at the Hallstatt UNESCO World Heritage Site.

photo credits: zek

ENVIRONMENT MINISTER STARTS UP NEW POWER PLANT IN HALLSTATT With a construction period of just around 11 months, one of the most powerful small-scale hydro power projects in Upper Austria was implemented in the UNESCO World Heritage Site of Hallstatt. The project is backed by the Austrian Federal Forestry Office and the community of Hallstatt. After the plant had started up trial operation at the beginning of September 2013, the official inauguration ceremony was scheduled for 2 July 2014. The grand opening was performed with the Austrian Environment Minister Andrä Rupprechter pressing a button to set the 6-nozzle Pelton turbine in motion. This showpiece power plant in the famous Salzkammergut region delivers around 20 million kWh of power to the grid every year. In future, it will be possible to supply around 4,500 households with electricity produced from renewable energy from Hallstatt. This is equivalent to an annual saving on CO2 emissions of around 16,800 tonnes.

photo credits: EWZ

ALBIGNA RESERVOIR DRAINED FOR REFURBISHMENT To enable the replacement of sealing components and refurbishment of various parts of the facility, the Albigna reservoir was completely drained in February 2015 by its operator, Swiss-based energy utility EWZ. This revealed the unusual sight of the 115 m high dam wall at 2,100 m above sea level. Heavy-haulage helicopters and the operator’s cableway are used to make the construction site accessible so the the extensive work in this high alpine terrain can go ahead as planned. The engineers working on the project have to withstand extreme climatic conditions such as sudden snowfalls and cold spells. If everything goes to plan, the revision will be completed by summer, although the refilling of the reservoir is scheduled to begin already in May.

The order from MeyGen follows the successful completion of tests with ANDRITZ HYDRO Hammerfest’s HS1000 pre-commercial demonstrator turbine (graphic) at the European Marine Energy Centre in Orkney, Scotland, in 2014.

May 2015

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PILOT PROJECT FOR THE USE OF HYDRO POWER IN PARAGUAY According to Víctor Romero, the director of the institution ANDE, a new power plant is being planned in Paraguay. The plan is that this should dam the Rio Ypané in Belén near to Concepción and reach a capacity of 14 MW, reports Última Hora. The works are scheduled to begin this year, with the project due to be completed in 2018. The application for approval of the building project has already been submitted to the relevant authority, Fonacide, which decides on where funds are to be allocated. The proposed plant is a pilot project which it is intended will enable experience of constructing and operating small-scale hydro power plants to be gathered. Total costs of around 50 million US dollars are expected, and the intention is that the project will also create 1,500 jobs.since 1926.

May 2015

photo credits: Le Grand Portage / Rehman / Wikimedia photo credits: RWW

KAHLENBERG POWER PLANT IS BACK IN OPERATION Just before the turn of the year, Mülheim's lord mayor Dagmar Mühlenfeld and the technical director of RWW, Dr. Christoph Donner, officially reactivated the completely overhauled turbine at the Kahlenberg hydroelectric power plant. After running for almost 90 years, the largest of the three turbines, a Francis turbine, underwent an overhaul. In the project phase lasting for more than one year, the two runners, each weighing 12 tonnes, were replaced and the two shafts and bearings were refurbished. The cost of this was 1.3 million euros. "This turbine now sees the overall output of our power plant add up to 5 MW again. This means that we generate around 17 GWh of electricity every year. This would be enough to supply 5,000 households for an entire year. But we consume this power to deliver our water supply," says Donner.

The new run-of-river power plant on the River Ybbs produces 12.8 GWh of clean energy every year with the two Kaplan S bulb turbines.

photo credits: zek

NEW HAUSMENING POWER PLANT ON RIVER YBBS REPLACES TWO OLD, OUTDATED POWER PLANTS The two power plants of Hofmühle and Theresienthal – both located on the River Ybbs – have been regarded as old and outdated for many years. The structure of the buildings and technical equipment seemed to be suitably dilapidated. The end was in sight. Over the last two years, a single, modern run-of-river power plant has now been constructed to replace the two existing plants. This has not only restored the ability of the fish to gain access in both directions at the site of the power plant, but also pushed the generation of electricity to previously unknown heights. With the two Kaplan S bulb turbines from GLOBAL Hydro, the new plant belonging to the Soravia Group produces around 12.8 GWh in a normal year. This represents an increase in yield of around 80 per cent compared to the old existing facilities. Thanks to the establishment of the underwater section rich in structure, it can be expected that the ecological conditions of the waterways will be enhanced in the medium to long term – and the new power plant also represents an improvement with regard to flood protection.

The 32 turbines of the Chinese dam have a combined capacity of 22.5 million kW.

The two overhauled Francis runners for the Kahlenberg power plant. Powerful impetus for hydro power in Paraguay.

photo credits: Edgar Funk / Wikimedia

WORLD RECORD FOR THREE GORGES DAM Last year the Chinese mega-power plant at the Three Gorges Dam produced 98.8 billion kWh of electricity. It has therefore surpassed the previous world record holder from South America. Although Brazil's Itaipu hydroelectric power plant has a lower installed capacity than the Three Gorges Dam, for many years it held the world record for generating electricity from hydro power. In 2013, the plant in Brazil generated 98.6 billion kWh of electricity. According to the operator of the power plant on the Yangtze River, the China Three Gorges Corporation, the 98.8 billion kilowatt hours produced last year are equivalent to a saving of 49 million tonnes of coal and a reduction in carbon emissions of around 100 million tonnes. The dam and the hydroelectric power plant was completed in 2006, and all of the turbines started operating two years later.

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BENEDICTINE MONASTERY OF MARIENBERG BELIEVES IN THE POWER OF NATURE The efforts to deliver the monastery's own hydro power plant dragged out over more than a decade. It was only two years ago that the powers-that-be at the Benedictine monastery of Marienberg in the area of Burgei in South Tyrol - the highest Benedictine abbey in Europe at an altitude of 1340 m above sea level - were able to implement their ideas of an environmentally friendly and decentralised ecofriendly power plant. The new high-pressure power plant on the Meltzbach river in the Vinschgau district has now been reliably supplying green electricity since the end of 2012. The 4-nozzle Pelton turbine with a maximum output of 315 kW generates around 1.8 GWh a year. The revenue from selling electricity is used primarily to maintain the extensive buildings and property.

The tidal lagoon hydropower plant in Swansea Bay, Wales, will have a total capacity of 320 megawatts.

photo credits: zek

ANDRITZ HYDRO TO SUPPLY EQUIPMENT FOR THE WORLDâ&#x20AC;&#x2122;S FIRST TIDAL LAGOON HYDROPOWER PROJECT IN SWANSEA BAY Following an international bidding process, Tidal Lagoon Swansea Bay plc. has appointed the consortium by GE/ANDRITZ HYDRO as preferred bidder for supply of the electromechanical equipment for the worldâ&#x20AC;&#x2122;s first tidal lagoon hydropower project in Swansea Bay, Wales. Start of commercial operation is scheduled for 2019. The tidal lagoon hydropower plant will be located in the Severn Estuary and will have an installed capacity of 16 units with over 20 megawatts each. The Severn Estuary has the second highest tidal range in the world, and in this estuary, Swansea Bay benefits from an average tidal range of 8.5 meters during spring tides. The plant will supply clean, renewable, and predictable power for over 155,000 homes and contribute significantly towards national carbon emission reduction targets with over 236,000 tons of CO2 saved each year.

graphic credits: Andritz

HYDRO

The plant on the Meltzbach river in the Vinschgau district in the area of Burgeis in South Tyrol is owned by the Benedictine monastery of Marienberg.

May 2015

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photo credits: Energie AG

HPP Traun-Pucking is Energy AG’s largest run-of-river power plant. Two Kaplan turbines generate electrical energy for around 60,000 Upper Austrian households. The long-established South Tyrolean company is already being managed by the third generation of the family.

ALL DOCUMENTATION FOR THE RIEDL ENERGY STORAGE DAM PROJECT NOW SUBMITTED The Jochenstein AG Danube hydroelectric power station is operated by the ‘Verbund’ energy company, and on the 26th February the final documents for the bilateral licensing procedure for the planned Riedl energy storage dam project were submitted to the Regional Office in Passau. These documents fill 63 files and the authorities have all they need to begin the comprehensive research into the construction work planned. To be exact, the Riedl energy storage dam project involves Verbund AG building a pumped-storage hydropower plant, a project it has been trying to implement for years. The pump and turbine power outputs - each 300 MW – will enable the completed plant to provide an efficient and flexible means of storing and utilising electricity derived from wind power and photovoltaic plants. There is also a plan to build a new fish pass at the Jochenstein AG Danube hydroelectric power station.

May 2015

photo credits: zek

TROYER AG CELEBRATES 80 YEARS IN BUSINESS Customer satisfaction has been a central tenet of the corporate philosophy of the South Tyrolean hydropower specialists Troyer AG for decades. The company values its customers. Many of them have been customers for a long time and Troyer AG knows how important they are to the success of the company. So, on the 24th October last year, they were invited to join the employees for the 80th anniversary celebrations of the Sterzing business’s foundation. Maria Luise Troyer is the company’s former senior executive, having run the business until three years ago. She explains: ‘We have established genuine friendships with many of our customers’. Mrs. Troyer still provides active support and advice for the younger generation now at the helm.

Verbund Project Manager, Dr. Dominik Mayr, in front of a scale model of the planned Riedl energy storage plant.

photo credits: Troyer

UPPER AUSTRIAN HPP TRAUN-PUCKING TO UNDERGO EXTENSIVE REVISION HPP Traun-Pucking has been a provider of clean energy from hydropower since 1983. Ever since it has been operating, Energie AG’s high-capacity hydropower plant has been subjected to regular inspections and maintenance. During the most recent inspection, a bearing was found to be defective, which is why an extensive revision, including the complete dismantling of the machine unit, were performed during the cold season. Since their commissioning, the two turbines have generated around 6.6 billion kilowatt-hours of clean energy from hydropower. During the extensive revision, one of the two Kaplan turbines, each measuring 4 m in diameter and weighing 170 tonnes, was dismantled and subjected to a detailed inspection. The required revision work kept the service engineers on a heavy schedule for weeks on end. In the spring of this year, both machines were back in full working order.

„The power house has been semi-buried and the pipeline and grid cable completely buried to ensure that any construction works blend into the local environment,“ explains RWE Innogy UK’s senior projekt manager Mary Drury.

photo credits: RWE

RWE INAUGURATED MALDIE HYDROELECTRIC POWER PLANT In May 2014, RWE Innogy officially inaugurated its hydroelectric storage scheme Maldie in Scotland. The construction took 20 months, with the first turbine becoming operational in May 2013 and the second in March 2014. With an installed capacity of four megawatts (MW), the plant can generate around 15,000 megawatt-hours of electricity a year to supply around 3,000 homes with renewable energy. The investment volume amounts to more than 17 million euros. Maldie is the first storage scheme RWE Innogy commissions in the UK. It uses water from a catchment area of around 22 square kilometres. A weir located at the outlet of a Loch will raise the water level by 1.5 metres to form a storage reservoir. 2.8 cubic metres of water (19 full bathtubs) will be abstracted per second at the weir and fed into 2km of buried pipeline connecting to a buried powerhouse located 170 metres below the weir, which contains two 2MW Francis turbines.

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photo credits: Schmuttel_pixelio.de

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NEWS FROM BRUSSELS: EXCITING TIMES FOR THE SMALL HYDROPOWER SECTOR Following the declared goal of President Juncker in July 2014 to “become the world number one in renewable energies”, the European Commission published its strategy to achieve a resilient Energy Union with a forward-looking climate change policy at the end of February 2015. [by Dirk Hendricks, Brussels]

EREF CAMPAIGNS FOR SHP SECTOR It will be crucial for the renewable energy sector to play an active role within this development process by including updates and requests in the European and national plans. Especially the small hydropower sector has the chance to secure and enhance its rightful place as an equally important part in the EU renewable energy mix and to create business opportunities for the many small and medium-sized enterprises throughout Europe. The Small Hydropower Chapter of the European Renewable Energies Federation

(EREF) actively campaigns on EU level for favourable and secure long-term investment conditions for the small hydropower sector. EREF is the federation of national renewable energy associations from EU Member States, representing all renewable energy sectors. Its objective is to defend the interests of independent power, fuel and heat production from renewable sources and to promote nondiscriminatory access to the energy market. EREF strives to create, maintain and further develop stable and reliable framework conditions for renewable energy sources. FIGHT AT THE GENERAL COURT OF EU Next to regular meetings with key EU decision-makers on small hydropower issues, EREF has initiated annulment proceedings exclusively against chapter 3.3.2. of the Guidelines for Environmental and Energy Aid 2014-2020, which aim to severely limit the financial support for renewable energies. Currently, the case is pending at the General Court of the European Union. If the complaint turns out to be successful, this would be a very important and vital reassurance for all sectors of renewable energy. EREF staff members also actively promote the inclusion of small hydropower projects in

the list of the European Fund for Strategic Investments (EFSI) which includes € 315 billion for the time period between 2015 and 2017 to support sustainable investments projects. If you want to finically support and/or actively contribute to the policy campaign of the Small Hydropower Chapter, please contact Dirk Hendricks. [dirk.hendricks@eref-europe.org]

photo credits: Dirk Hendricks

ithin the next year, the Commission will develop their proposal for a new governance structure, electricity market design and a revised Renewable Energy Directive. Parallel to this, the Commission will start revising the Water Framework Directive from mid-2015 onwards. This revision offers the unique opportunity for the small hydropower sector to highlight the sustainable quality of modern hydropower technology which enables an entente cordial between the objectives of the Water Framework Directive and the objectives to change towards renewable energy based systems.

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photo: Kössler

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A Francis spiral turbine from the hydropower specialists of Lower Austria-based Kössler operates the traditional Dolgarrog power plant.

AUSTRIAN TURBINE MANUFACTURER DISPLAYS CORE COMPETENCIES WITH FIRST ORDER TO WALES The Dolgarrog plant is one of the most important hydropower plants in Wales, not only from a historical point of view but also because of its significance for the Welsh electricity industry. The plant, which was put into operation in 1924 and is now operated by RWE INNOGY UK, was partially renovated in the last four years at a cost of about 15 million GBP – around 21 million euros. The key elements of the remodeling project were the replacement of parts of the old steel penstock and the exchange of machine unit 4, a 10-MW turbine-generator unit from 1950. For the exchange of unit 4 the operators relied on the competency of Austrian hydropower expert Kössler, for whom the project marked the entry to the United Kingdom. This premier was abundant with technical challenges and thus was one of the most technically demanding projects that the experienced turbine manufacturer from Lower Austria had ever encountered.

olgarrog, a small village in Conwy County Borough in the northern part of Wales, was an important site during the early industrial development in the 18th century. In the beginning flour mills were established in Dolgarrog and after a while textile manufacturing companies and saw mills popped up as well. They all used water from the River Conwy, passing near Dolgarrog. The abundance of water as well as the mountainous terrain of the picturesque surroundings also met the requirements for an electrical utilization of hydropower. The construction works on the Llyn Eigau Dam, which was to serve as a reservoir for the planned Dolgarrog hydropower plant, began as early as 1911. However, this project ended in a tra-

gedy due to its poor construction. After five days of heavy rainfall disaster hit the area. On November 2, 1925 the dam broke and all ponded water poured into the neighboring Coedty Reservoir, whose dam walls burst as well. The flood struck the small village, killing 17 people. It would have been more had many of the residents not been at a film performance at the safe local theater building at the time of the incident. A subsequent examination found that the work on the foundation had been insufficiently executed and concrete of poor quality had been used. In 1930 the British parliament passed the “Reservoirs Safety Provision Act” as a consequence of this tragedy. It was introduced to guarantee the safety of dams and is still in effect today.

TWO POWER PLANTS UNDER ONE ROOF The Dolgarrog power plant was put into operation in the same year as the incident happened. It was designed to provide electricity for the local aluminum works, which it did until the 1940s, when the smelting works were stopped and the factory became less and less important. In the early 2000s the factory was closed and there are now plans to turn the area into a leisure park. While the traces of the aluminum industry slowly fade, the Dolgarrog power plant is still operating. Today the plant, with an installed capacity of 32 MW, represents one of the most important top-performance electricity suppliers of Northern Wales. However, Dolgarrog actually comprises two independently operating May 2015

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A view onto Coedty Reservoir, through which water is conveyed from the Conwy Valley to the Dolgarrog power plant.

SAFETY FROM PRESSURE SURGES In 2009 RWE INNOGY decided to replace the above-ground section of the original penstock from the 1920s and to restore machine unit 4 at the same time. Not only safety issues played an important role in the planning, but also landscape aesthetics, resulting in an underground installation of the penstock. Safety was the main reason for the exchange of the machine unit. “The previous plant was designed and equipped with a pressure regulator to manage transient conditions – i.e. any possible pressure surge situations. The risk associated with such a valve was too high and so the client decided on a modern and less complex unit that meets safety concerns with improved technology,” Karl Henninger, project manager of Kössler, explains. RWE INNOGY spent approximately 15 million GBP on the project. After the preliminary design had been carried out in the fall of 2010, the project managers took time in 2011 and the beginning of 2012 to develop the most effective technical solutions with

Foto: RWE INNOGY

plants, whose turbine-generator units are set up under one roof, in one powerhouse. There are basically two process water channels. One is fed from the Cowlyd Reservoir and is considered a “high head” scheme, meaning a high-pressure plant. The other channel takes its process water from the Coedty Reservoir and is a “low head” scheme, a low-pressure plant. However, this description should not be taken too literally, as the “low head” scheme still uses a head of about 264 meters. The improvements were made on the “low head” section only.

regard to the life of the machine unit and environmental protection. The contract for the construction project was obtained in 2012. The order received by Kössler included the installation of the turbine and the generator, the ball valve, the corresponding hydraulic power unit, lubricating oil, the cooling system for the mechanical segment, the automation as well as the low-voltage element for the electricity. In addition Kössler was commissioned to dismantle the old and install the new equipment. WORKING IN A NARROW SPACE In April 2013 RWE INNOGY took the “low-head” system off the electrical grid. During this time the old above-ground penstock was removed and machine unit 4 was

dismantled. This marked the start of Kössler's construction job in Dolgarrog, which in hindsight turned out to be one of the most challenging projects. “The project was from planning to commissioning one of the biggest technical challenges we had encountered until then. The assistance of our parent company Voith was a great help,” says Karl Henninger. In order to meet the technical requirements of the local conditions, a new hydraulic turbine design had to be developed in only a short time: a design that would satisfy all demands, achieve the necessary cavitation protection and attain the highest possible degree of efficiency. “This task was perfectly performed by our colleagues from Voith Development Center in York (US). They laid the basis for further construction

photo: Kössler

Large centrifugal masses had to be used to control transient conditions.

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LARGE CENTRIFUGAL MASSES Another key aspect of the project was controlling the transient conditions in the penstock in various operating scenarios. Based on the fact that the gross head was 263.81 meters the maximum pressure surge must not exceed 292 meters in any worst case scenario, this correlates with a pressure surge of about 10 percent. “No equalizing valves were allowed, as is usually customary. The reason was the 90-year-old remaining part of the penstock, which would not tolerate any pressure surges beyond that. We had to meet these demands with mechanical means, i.e. large centrifugal masses,” Mr Henninger explains. Another requirement was minimizing and simplifying maintenance. This aspect was important during the designing phase of the machine unit. Of course, robustness was a major factor as well, since the power plant is a top-performing plant. It is switched on and shut down quite often during the day. The output, however, will have to remain steady because the license allows no deviation. The advantage of the new Kössler Francis spiral turbine is that it takes less water to attain the nominal output of 10.18 MW. EXCITING NEW CHALLENGES “The project involved another challenge – to get all the appropriate licenses and to take all needed precautions for the installation. In the UK you have to get the approval of your client for the construction process as well as that of HSE. There are special conditions in the UK that you have to consider,” states Karl Henninger. He adds that the experts had to pick up certain peculiarities about how work is done on the British Isles. Having a reliable and competent partner in Wales to The turbine runner was milled from a single block of stainless steel.

photo: Kössler

and assembly works. In addition Voith experts from Heidenheim, Germany, accompanied all these activities,” says Mr Henninger. The plan was to replace the old Boving turbine from 1950 with a contemporary Francis spiral turbine, which had to meet many different criteria. One aspect was to maintain the specified turbine axial height. Another one was to build a turbine of comparable cubage that fitted with the previous penstock diameter and the predetermined axial position. To make matters worse the space available was extremely narrow. “Although only four machine units, out of the five originally installed units, were set up in the power house, the space was barely sufficient. Furthermore the old power house crane was not constructed for such masses. For this reason we had to dismantle the generator completely before delivery and assemble it again on the construction site with special gadgets,” adds the technical expert.

The new Francis spiral turbine is designed for a capacity of 10.18 MW.

take over the project management and handle all of the client's requests directly was an invaluable assistance to Kössler and essential to the success of the project. In the fall of 2014 the installation works on machine unit 4 were nearly completed. The commissioning and first tests turned out successful. Today both “low-head” machine units in Dolgarrog are operating again. It was a pleasant completion of a challenging project, which marked the company's entry to the hydropower market on the British Isles. LOCAL INVESTMENTS RWE INNOGY focused not only on the technical improvement of one of its most important hydropower plants, but also on guaranteeing the most environmentally-friendly procedure possible. 300 trees had to make way for the installation of the penstock along its route, but the operator planted 4,000 trees in that area as an ecologically balancing and accompanying measure. About 100,000 GBP were invested in preservation measures for nature and archaeological sites nearby. Furthermore streets and bridges for an improved infrastructure, a garden as a commemoration site for the dam accident of 1925 and a children's playground were built. RWE INNOGY is one of the leading operators, project developers and investors in the field of renewable energy in Wales. The hydropower plant houses units with an installed capacity of 44 MW. Thus the Dolgarrog power plant represents the most significant plant and is the central control station for the other power plants in the region. The successfully completed renovation will guarantee a reliable operation of the power plant and a clean electricity supply for Northern Wales for decades.

Technical Data for Dolgarrog „Low Head“ UNIT 4 w w w w

photo: Kössler

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Dam: Coedty Net Head: 254.78 m Turbine: Francis spiral turbine Nominal rotation speed: 750 rpm Energy output: 10,18 MW Generator: snychronous generator Penstock total: approx. 5000 m new earth-laid: approx. 1200 m

Head: 263.81m

Manufacturer: Kössler Runner Diameter Ø : 1340 mm

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Generator nomin. output: 12.500 kVA Material: steel Pipe Dimension Ø: DN900

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photo: Eidefoss

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As a ‘water-to-wire’ provider, the Siemens Competence Centre for Small Hydropower, Salzburg has built a modern small hydropower station on the Smådøla river in Norway. The site before the construction of the new hydropower station.

SIEMENS SUPPLIES AND INSTALLS SMALLSCALE HYDROPOWER STATION IN NORWAY 300 km north of the Norwegian capital Oslo, in the middle between two national parks at the river Smådøla, a new small-scale hydropower station is being constructed, which will provide 12,000 households with clean energy. The project is implemented and supervised by the Siemens Competence Centre for Small Hydro in Salzburg. The contract includes the supply and installation of all power plant components, from the turbine to the grid (“water-to-wire” package). The contract was awarded by Norwegian power plant and network operator A S Eidefoss. For Siemens, this project marks the entry into the Norwegian small-scale hydropower market.

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fectly. Siemens is a reliable partner in terms of investment protection, which was crucial in this project,” says Jan Harald Bakke, Project Leader at Eidefoss. FLEXIBILITY DURING THE PLANNING PHASE During the planning stage of the project, Siemens provided the customer with advice on the electrotechnical design and component optimisation. The flexible service and know-how provided by Siemens, combined with the use of the latest planning tools, allowed for changes to be integrated quickly into the project plan without causing any delays. For example, a grid analysis was performed in advance to determine the influence of the current feed on the voltage behaviour within the grid. Siemens also worked in close cooperation with the civil engineers to optimise the power plant layout and accessibility of the equip-

The power house is home to three differently dimensioned Francis turbines.

photo: Siemens

he hydropower plant is designed as an underground facility, with water being supplied by way of a pressure tunnel. This means that the Smådøla is left to flow undisturbed above ground while contributing to power generation “down below”. Three turbines of different capacity are to be efficiency optimised to generate a total of 15.21 MW, depending on the available volume of water. The plant is scheduled to be commissioned in 2015. Siemens was awarded the contract by Norwegian energy provider A/S Eidefoss. The order includes the supply of the entire mechanical, electrical and building technology for the water intake, the power house as well as a service building in front of it – i. e., a complete “water-to-wire” package. “We decided in favour of Siemens for this project, as their offer was technically convincing and met all our tender requirements per-

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photo: Siemens

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The Siemens engineers demonstrated their hydropower knowledge in the far north

ment with the indoor crane, and to prepare the required working areas and transport paths. A special challenge was posed by the distributed locations of the various high-volume power consumers, such as the ventilation units that supply fresh air to the tunnel and cavern. This made it necessary to install an additional grid level for energy transfer, including step-up and step-down transformers. Thanks to their experience, the Siemens engineers confidently mastered such tasks as connecting the power station to the grid at the Eidefoss control centre some 20 km away, or calculating an optimum switching matrix between the machines depending on the available water volume. THE CHALLENGE: INSTALLATION AND START-UP Creating local value is important to Siemens, which is why local firms were subcontracted for instillation work wherever possible. With “hands-on mentality”, Siemens foremen supervised the installation work, lending a helping hand where necessary. Due to the very limited space in the cavern and access tunnel, transporting the equipment to the installation side and storing it without obstructing other components posed a logistic challenge. With the construction site located in the Norwegian mountains, the installation work was accompanied by changing environmental conditions all year round. As a result, the Siemens team was constantly faced with challenges such as road damage due to heavy rain, or extreme snow conditions. However, careful pre-planning of transports and the excellent cooperation with Eidefoss allowed them to compensate for these influencing factors.

photo: Siemens

Access road to the power plant construction site in the deep of winter

In the end, the start-up went ahead in the winter, as planned. In the intake area, the Siemens engineers were faced with temperatures as low as –25 °C, wind speeds of up to 100 km/h and snowdrifts more than a metre high. Among other things, these conditions led to the intake gates icing over. But thanks to the dedicated personal effort of everyone in the Siemens team and local firms specialising in de-icing, this problem was eventually solved as well. Finally, the start-up process could be completed according to schedule. CONCENTRATED HYDROPOWER COMPETENCE IN SALZBURG Siemens Austria’s Small Hydropower Competence Centre in Salzburg is the global hub for the group’s worldwide small-hydropower business. With a product range covering everything from turbines to transmission lines, Siemens stands out as a single-source provider of all components for small hydropower stations. The portfolio includes everything from planning to engineering, delivery, installation and start-up of facilities up to 30 MW. Mechanical power station components such as turbines and generators are combined with electrical and control technology systems. So far, the Competence Centre for Small Hydropower in Salzburg has completed more than 400 projects worldwide. In addition to the alpine region, projects were implemented in southeastern Europe – Greece and Turkey, for example – and in Scandinavia.

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3 horizontal Francis Turbines including sluice valves and pressure pipeline 3 Synchronous Generators Generator output: 10.5 MVA 6.6 kV / 3,5 MVA 6.6 kV / 1.4 MVA 0.69 kV 3 Main Transformers (T1,T2,T3) T1: 10.5 MVA 6,6/22 kV T2: 3.5 MVA 6.6/22 kV T3: 1.5 MVA 0.96/22 kV 1 Aux. Power Transformator – 315 kVA 22/0,4 kV Medium-high voltage cable Medium-high voltage switch gear Steel hydraulics constrution catchment Overhead crane Standby power supply diesel generator Shielding method Control and communication system Turbine automation Low voltage distribution board Building technology

photo: Eidefoss

Technical Equipment

Dam in the Norwegian mountains at 1,000 m.a.s.l. near the tree line

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he river Ill has always been considered a lifeline for Austria’s westernmost town, Feldkirch. As fas back as the Middle Ages, water from the river was utilised to power hammer- and sawmills, tanneries and grain mills. For this purpose, the water was diverted from the river and channeled to the facilities. “The town’s first power plant was built in the years 1905 and 1906 in the same spot where the old town mills used to be,” says Hans-Jörg Mathis, head of the Electrical Energy division at Stadtwerke Feldkirch. “This made Feldkirch the first town in Vorarlberg to have its own communal power utility.” Over the following decades, the growing electricity demand led to repeated discussions about the construction of a power plant on the river Ill. Most recently, this happened in

Where the Ill flows into the Alpenrhein, Stadtwerke Feldkirch have been putting up a new hydropower plant within the past two years. An essential success factor consisted in full compliance with requirements in terms of ecology, landscape conservation and high-water protection

the years between 1981 and 1987, when the Vorarlberg-based Illwerke contemplated the construction of a chain of power plants. However, the proposed extensive dam-building measures met with strong public resistance, so the plan had to be dropped eventually. RECONSTRUCTING THE ILL ESTUARY Still, the human impact on the area surrounding the estuary became more and more noticeable as time went by. The extraction of gravel from the headwater region of the Rhine during the first half of the thwentieth century caused a deepening of the riverbed. “In the 1950s, the Ill and Rhine were almost on the same level in the estuary,” says Mathis. “But over time it became necessary to bring large stone blocks into the estuary to prop up the riverbed of the Ill and to ensure the stability of the high-water dams upstream.” As it turned out, however, the gradually built up stone ramp was not as stable as expected. This became evident during the massive flood

in May 1999, when water volumes of up to 560 m3/s washed away the entire inner bend of the Ill estuary. Massive armour stones were brought in as an initial measure. This was followed by a comprehensive estuary reconstruction project, which extended in scope to the cut bank on the Swiss side of the border. The course of the river was altered in the estuary area so the Ill now takes a right-hand bend and empties into the Rhine at an acute angle by way of two block ramps. The project was completed in 2002. TRACKING DOWN ECOLOGICAL SHORTCOMINGS Only a few years later, in 2005, the idea of a possible hydroelectric utilisation of the Illspitz estuary area emerged at Stadtwerke Feldkirch. A market potential study was initiated, which confirmed the economic feasibility of such a project. “Considering the failed attempts in the past, our main guiding principle was to exercise extreme sensitivity in the

The flood of October 2012 devastated the construction site. The left-hand dyke was washed away along a 60 m stretch. The gravel material formed an extensive bank, diverting the river to the cut bank on the Swiss side of the border.

photo credits: Stw. Feldkirch

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Foto: zek

After nine years of intense preparation, planning and implementation, Stadtwerke Feldkirch’s new Illspitz power plant has been officially inaugurated. During the opening ceremony on October 5, 2014, the facility was inaugurated and presented to the public as part of an open-day event. The most characteristic feature of this power plant, which is situated at the estuary where the river Ill flows into the Alpenrhein, is the complex concept behind it, which meets the most stringent requirements in terms of natural and landscape conservation, and flood protection. Equipped with two 3.6 MW Kaplan bulb turbines, it will generate 30 GWh of clean energy per year.

photo credits: Stadtwerke Feldkirch / Mathis

CITY OF FELDKIRCH BRINGS ECOLOGICAL MODEL FACILITY TO THE GRID

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photo credits: zek

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Downstream view of the weir gate construction and block ramp

three key areas of ecology, landscape conservation and flood protection. With that in mind, we got busy working out a concept for a runof-river power plant that was to exploit existing synergies as much as possible. Of course, we also had to ensure compliance with the European Water Framework Directive,” explains Hans-Jörg Mathis. As a result, the energy economical objectives were essentially made subject to the ecological requirements, and not the other way round. The initial task was to track down ecological shortcomings at the project site to reduce or possibly eliminate them as part of the planned project. Rescuing the alluvial forest “Apart from two other ecological issues, our main focus was on the critically low ground water level in the adjacent riverside forest, which was caused by the deepening of the Rhine riverbed over the previous decades. Due to the low ground water level, the area was in immediate danger of losing the essential characteristics of an alluvial riverside forest and, as a result, a lot of rare plant and animal species. When we first proposed our solution concept to the responsible politicians and officials, we realised that this might open a door towards the construction of our proposed power plant.” Next, a series of reports was commissioned to provide more details on bed-load discharge, high-water protection, and the geological and ecological conditions. COMPREHENSIVE PACKAGE OF MEASURES Working with the planning office of Dr Hutarew & Partner, Stadtwerke Feldkirch proceeded to work out a concept and planning permission application documents for a power plant at the Illspitz (Ill estuary). The concept called for a relatively modest impoundment level of 3.5 m relative to the average water level, with a triple weir gate facility. The intake structure was to be erected on the orographic left bank, at the outer bend of the Ill, flanking the Rhine. From there, the used motive water was to be discharged directly into the Rhine in the area of the original Ill estuary.

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Flow Rate: 2 x 60 m3/s Turbines: 2 x 1 Bulb-Kaplan-Turbine Runner diameter Ø: 2850 mm Nominal rotation speed: 157,89 rpm Generator: synchronous generator Generator output: 4.000 kVA Number of poles: 38 cos phi: 0,9 concrete: 30.000 m3 Start of work: August 2012 Inauguration: October 5th 2014 Annual energy capacity: approx. 30 GWh

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Head: 4,5 - 8,5 m Manufacturer: ANDRITZ HYDRO Number of Blades: 4 Output: 7,2 MW Manufacturer: ELIN Motoren Current: 905 A Generator diameter Ø: 2900 mm Generator weight: 32 to steel hydraulics: Künz commissioning: August 2014 capital investment: 35 Mio. Euro

The list of required ecological measures included the extension of the existing estuary branch by around 1 km in the shape of a near-natural raceway with regulated supply, as well as the regulation of the ground water supply for the alluvial forest. Also, the solid riverbed construction of the main Ill river channel was to be removed along a 300 m stretch to create a 250 m shallow water zone in the reservoir area near the gates. Finally, the package of ecological measures was to include three fish ladders and an additional innovative downstream fish pass. OFFICIAL BACKING FOR THE PROJECT However, it was not until several years later that the first excavator shovel was able to start digging into the gravelbed at the Illspitz. The political and administrative permission process lasted from 2008 until July 2011, when, finally, the water usage permit was granted. In view of the local community’s overwhelming approval of the power plant project, Feldkirch’s town fathers also gave the project their unanimous consent. Soon after that, calls for tenders for key components and equipment were issued. The construction planning and tender process was supervised by the Pforzheim-based team of engineers in collaboration with the local planning office of BHM INGENIEURE. Initial preparatory work began in autumn of 2011, with the construction of the conduit for the increased ground water volume in the Natural2000 zone at Matschels and the laying of the power cables that were to be used for the construction site and and later as grid feed-in lines. The earth works for the new 1 km side channel were also initiated in the spring of 2012 in preparation for the construction of the power house. FLOOD DAMAGE August 8, 2012 marked the official kick-off for the construction work. The excavation pit and specific limiting conditions imposed particularly challenging conditions, as Josef Feldbauer of BHM INGENIEURE explains. Only a few months into the construction, the project suffered a serious setback. The massive flood in the autumn of 2012 caused an eight-week delay and required the reconstruction of the formation level. “In view of the construction and excavation work ahead of us, our focus was on the underground pressure level, which we had to monitor constantly by means of pressure sensors. Using vacuum wells, we gradually reduced the water pressure in the sealing layers beneath the power house foundation.” MORE WATER FOR THE TURBINES Fortunately, the high water did not affect the ongoing work on the weir gate system. While installation work on the first weir gate went ahead in the autumn of 2013, the project leaders had some pleasant news for the public: “The turbines can process more motive water than we originally expected. Instead of 45 m3/s, they have an actual flow capacity of up to 60 m3/s each. They were provided by hydropower specialist May 2015

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photo credits: Stw. Feldkirch

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Lifting and installing the 4-blade turbine by ANDRITZ HYDRO.

ANDRITZ HYDRO Ravensburg, with whom have had very positive experiences in the past. However, this increase in processing capacity required a re-negotiation of the water rights. This was granted, not least because the the plant’s ecological characteristics, including the length and height of damming, remained exactly the same. Also, there was no reason to assume that this would have any adverse effect on the ground water level. From an energy economical point of view, we are pleased to be able to utilise the additional 120 m3/s, which occur over a period of around two or three weeks a year. Overall, this give us a sizeable 12 per cent increase in standard capacity,” explains Hans-Jörg Mathis. A HEART OF HIGH-END TECHNOLOGY The technical milestones were completed already in mid-April of 2014 with the delivery of the two Kaplan bulb turbines. With the help of a

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Final installation work being performed on the generator, before the bulb – the enclosure – is sealed.

telescopic crane, the components, each weighing 47 tonnes, were lifted, positioned and installed with millimetre precision. Once again, the installation team from ANDRITZ HYDRO demonstrated its high level of competence. The installation of the generators was scheduled for the following day. Installing the 32-tons generators by ELIN Motoren, which measure 2.9 m in diameter, again required the use of the telescopic crane. As on the day before, the installation work went ahead without a hitch. An essential requirement for the machine solution, imposed by the operators, was that it had to be gearless. This suggested a bulb design, where the directly coupled synchronous generator is submerged in motive water and thus cooled at the same time. By aligning the turbine horizontally inside the “bulb” housing, ANDRITZ HYDRO has not only achieved an extremely compact design that is ideal for low heads, but has provided a turbine solution that is high in efficiency and low in noise.

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photo credits: Stw. Feldkirch

Hans-Jörg Mathis (left), with members of the Vorarlberger Illwerke team visiting the construction site, and the 2.85 m Kaplan runner in the background.

The ultimate availability and durability of the machine unit are guaranteed by the high quality of its components. This includes the fourbladed runner as well as the generator, which was provided by long established manufacturer ELIN Motoren, which is based in the Styrian town of Weiz. Based on a brushless design, the synchronous generator is equipped with 19 pole pairs and has a rated apparent power of 4,000 kVA. At 157.89 rpm the rotor revolves exactly at the same rated speed of rotation as the runner. It is this extremely low rotational speed that ensures an ultimately ‘fish-friendly’ operation.

A MODEL PROJECT After its successful inauguration, hydropower plant Illspitz finally went into regular operation. For the project leaders, almost a decade of planning and implementation had finally come to a truly happy end. In times when it is becoming increasingly difficult to ensure the viability of a power plant project, the new Illspitz power plant has attracted much attention both in Austria and across the border in Switzerland. The reason for this, rather than the facility’s 28 to 30 GWh of annual output to the grid, is the overall concept behind it all. If it is possible to put up a power plant in the sensitive landscape of the federal state’s largest alluvial forest region next to a “Natura 2000” zone, and if this ends up adding actual value to the ecology and landscape, then those responsible must have done a lot of things right. Overall, around € 35m were invested into the project, including € 4m of green energy subsidies and another 4 million raised through a civic participation programme. With the capacity now successfully increased to 60 GWh overall, the town of Feldkirch today is able to supply all of its households with electrical energy from its own, clean production.

photo credits: Stw. Feldkirch

SUCCESSFUL COMMISSIONING Initial contact with power plant water was made on July 26. Once the sheet piling had been put up in front of the intake and the weir gate system was prepared for reservoir operation, it was time to go ahead with the hydraulic start-up of the first machine unit. Not long after that, the second unit was taken into operation as well. On August 4th the time had finally come. The Mayor of Feldkirch, Mr Berchthold, together with Stadtwerke representative Mr Keckeis and Managing Director Manfred Trefalt took the

opportunity to push the start-up button. With both machines successfully put into trial operation, the project had entered its final phase. Apart from the usual fine tuning of the turbines during the trial run, a series of final tasks – some smaller, some more extensive, remained to be done. Everything was supposed to be ready for the great day of the inauguration and official presentation to the public of the new power plant: October 5th. The inauguration ceremony was attended by many guests of honour and members of the public, who had repeatedly confirmed their support of the power plant project.

A power plant with a high attraction factor: the official inauguration of the new facilities was celebrated in glorious weather, attended by around 5,000 interested members of the public.

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photo credit: Künz

Designed as segments with attached weir baffles, the 15 m wide weir gates ensure the reliable discharge of excess water and bedload.

HYDRO STEEL ENGINEERING SPECIALIST PROVIDES EQUIPMENT FOR AUSTRIA’S WESTERNMOST POWER PLANT Floods like the ones in 1999 and in October 2012 showed the kind of natural forces at work in the area where the Ill flows into the Rhine – and the massive amounts of bed-load carried by the river in extreme situations. It was reason enough for this aspect to be taken into consideration during the planning stages for the power plant, with a particular focus on robust, functional and reliable hydraulic steelwork structures. A project of this dimension demanded a hydro steel engineering specialist with extensive experience and a solid reputation – a provider like Hans Künz GmbH in Hard.

photo credit: Künz

he critical issues of high-water protection and bed-load movement in particular meant that the power plant constructors would have to come up with ultra-solid solutions. To the planners it was clear from the beginning that a job like this would require hydro steel structures of the highest quality. With all that in the background, the contract was awarded to renowned hydraulic steelwork engineering provider Hans Künz GmbH. The contract for the hydraulic architecture of hydropower plant Illspitz included three radial gates with flap gates for the weir structure, as well as two intake trash rakes, a set of dam beams, two outlet gates, two cable suspended trash rack cleaners, one coarse screen, and one needle rod. “The flood of 2012 was an important influencing factor for our project. Although Künz was not affected directly, the consequences of the event confronted us with numerous challenges throughout the project, while the Stadtwerke Feldkirch kept to their ambitious goal of going into trial operation in the summer of 2014. Thanks to the close cooperation of everyone invol-

Two of the three weir gates after the dry run

May 2015

ved and their constant focus on the goal ahead, we were finally able to celebrate the official inauguration of the plant on the first weekend in October,” says Johannes Galehr, project manager at Künz and joint project lead with his colleague Jürgen Feuerstein. ALTERNATIVE SPILLWAY SOLUTION WINS THE DAY The core component of the hydraulic engineering structure are the 15 m wide radial gates with attached flap gates. This had not been the plan from the beginning. “Originally, the plans called for a different gate system with an automatic opening mechanism. However, in the end our solution with three structurally identical radial gates with attached flap gates won out, as it provides a larger overall outlet cross section,” explains Jürgen Feuerstein. Using the attached hydraulic flap gate, each of the gates can be used for impound regulation while providing an efficient way of clearing away driftwood and debris material. Unlike the usual impound gates, the flap gates are rather large compared to the overall cross sectional area. This construction required a lot of expertise on the part of our engineers. At maximum storage level, each of the gates is able to drain 50 cubic metres of water per second. “The levelcontrolled opening mechanism for the gates provides extra protection, as they can drain the entire discharge volume of the river Ill, even in case of a power outage, by purely mechanical means,” says Feuerstein. In case of large discharge volumes, the weir gates are opened all the way to allow for the bedload to be carried off. CUSTOMER-ORIENTED SOLUTIONS BY KÜNZ Another essential hydraulic steelwork component, the turbine discharge gates, were installed facing towards the Rhine. Their control mechanism is linked to the turbines, which allows them to be deactivated in an emergency to prevent them from being damaged.

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Providing another important function, the new trash rack cleaners were designed by Künz as stationary cable-operated TRCMs. What makes these machines rather special is their ability to comply with hydro-ecological standards that require the debris to be transported along to the tailwater area. For this purpose, Künz installed flap gates. A separate channel system has been realized, which runs parallel to the fish pass towards the tailwater area. This hydro-ecological feature not only ensures that essential organic substances remain in the water, it even saves operators the cost of separate disposal. Another special feature implemented by the experienced hydo steelwork engineers from Hard was a needle dam construction. As Johannes Galehr explains, “In general, the needle dam-type weir is a well-proven solution, although it is rather rare in these regions, and Künz had never done one of the required design before. The fact that the construction and commissioning went ahead without any problems gave impressive proof of the Künz team’s ability to provide an optimum response to special customer requirements. The needle frame is designed so it can be lifted into the water and pulled towards each of the three gates with minimal effort. This makes needle dam also perfectly suited as an closing device for revisions.”

photo credit: Künz

HYDRO

Lifting and adjusting the 26-tonne weir segment required millimetre precision

MILESTONE IN MARCH 2013 As for the project schedule for the hydro steel engineers, manufacturing of the first components began in August 2012, following the general kick-off to manufacturing in April. Installation work began in January 2013. Over the following weeks, the Künz installation team had to put all their experience into fitting radial gates 2 and 3 with the weir segments within the scheduled time frame. “The two segments with attached flap gates were delivered on March 11th, and their installation was scheduled for the very next day. Using a telescopic crane, our engineers lifted, aligned and installed the 26-tonne components with milli-

metre precision. Everything went smoothly,” says Feuerstein. That completed the first milestone of the power plant project, and the overall facility was inaugurated in late July 2014. Hydropower plant Illspitz is one of the most significant reference projects in Künz’ company history, not just because of the geographic proximity and the future-oriented concept behind it, but primarily because it allowed the Künz team once again to demonstrate their competence. This competence is the result of decades of experience in heavy-duty hydraulic steelwork engineering, and it is being put into practice in all business areas by a young, creative team of highly motivated engineers.

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Since 2005, the Ukrainian company Kommertsconsult has been actively involved in renewable energies in Transcarpathia, in the western part of Ukraine. Previously the focus had primarily been on exploiting hydro power and gaining various different experiences. Based on these experiences, the managers in charge decided that for their latest power plant project – Shypot 2 – they would place their trust in hydro power technology from the Alpine region. They discovered a highly innovative and pragmatic partner in the form of the South Tyrolean Markus Wild, who was willing through his company Wild Metal to deliver Alpine hydro power technology to Transcarpathia. And this was done with great success: Equipped with high-end hydraulic steelwork from Wild Metal and highly efficient turbine technology from the company Troyer AG, the customer was able to deliver a resoundingly positive verdict on the South TyroleanUkrainian cooperation.

ranscarpathia, the most westerly province in Ukraine, is around 40% larger than South Tyrol and has roughly twice as many people living in it. However, the comparison when it comes to hydro power comes down in favour of South Tyrol: Whereas there are around 1,000 hydroelectric power plants in operation in the free province, in Transcarpathia they number just seven. One company which is involved with renewable energies in general and hydro power in particular is the company Kommertsсonsult, which belongs to the energy group RENER with its headquarters in Uzghorod - the capital of Transcarpathia. The company currently operates three hydroelectric power plants which each generate approx. 1 MW of power and two photovoltaic installations with a maximum output of 5 and 10 MW. In 2005, the first applications to obtain the permits to construct hydroelectric power plants were launched. To be allowed to build such plants, permits from both state authorities in Kiev and from the province are required. The most important element at the start of a project is to win the approval of the local community

May 2015

photo: Wild Metal

SOUTH TYROLEAN HYDRO POWER TECHNOLOGY SCORES POINTS IN WEST UKRAINE

Both in terms of the external appearance and the hydro power technology installed, the Shypot 2 power plant in western Ukraine compares favourably with modern, Alpine small-scale hydroelectric power plants

concerned. In general, 140 permits need to be obtained to implement a hydro power project. For the final permit to start operating the plant and feed power into the public grid, the plant must first have been fully constructed. After this, the plant is inspected by the local authority and - if all of the regulations have been complied with - the operating licence is issued. The water usage permit is awarded for one to three years and must be renewed on a regular basis. The law which guarantees that the electricity produced will be purchased is initially valid until 2030. INITIAL EXPERIENCES OF HYDRO POWER With a great deal of commitment and dedication, the company Kommertsconsult was able in 2008 to obtain the first permit allowing the construction of the Krasna power plant. But a huge problem arose at an early stage here: It was incredibly difficult to find a competent project engineer. Although there are state institutions which in theory offer power plant planning, in actual fact they are unable to boast any experience in the area of smallscale hydro power. Ultimately, a Ukrainian project engineer was found after all. The plant was connected to the grid in 2010 with the first machine producing a maximum of 800 kW. In 2011, there was approval for an expansion with a second Francis turbine which was able to start operating in 2012. The second project to be implemented by the company is located on the Shypot River. In this case, the planning remit was awarded to Armenian engineers. This project involves the use of a Cink cross-flow turbine which produces around 1020 kW and was also able to begin operating in 2012.

SOUTH TYROLEAN DEMONSTRATES PIONEERING SPIRIT For the next project, the developers had resolved to deliver a showpiece plant in Ukraine featuring state-of-the-art technology. In one of the zek HYDRO journals, they had come across the innovative system for water intakes, the Grizzly rake from the company Wild Metal. On a tour inspecting hydroelectric power plants in the Alpine region, they also got to know the company Wild Metal and the product and appreciated the superior turbine technology from the company Troyer AG. In January 2013, the developers invited Markus Wild and Adolf Dengg to visit western Ukraine in order to visit the locations for the forthcoming projects and to assist them in deciding what should be given priority. The Shypot 2 project was the most advanced in terms of the permits that had been secured. It was agreed that Wild Metal would draw up the plant concept and the detailed plans. The definitive plans were drawn up in the in-house planning department to ensure that they conformed to the Ukrainian laws and standards. In a next stage, the company Wild Metal was again asked to supply all of the electromechanical plant technology along with the steel hydraulic engineering. This meant a considerable risk for the mediumsized company from South Tyrol, but this reflects the pioneering spirit of Markus Wild. DIFFICULT LAYING OF PIPES At the end of the 2013/2014 winter season, the construction work commenced with the preparation of the route of the pipeline, which required the felling of trees. As soon as the temperatures allowed, the first metres of

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photos: Wild Metal

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Water catchment under construction

The route of the pipeline runs for around 3 km on the side of a mountain along the forest road.

the DN 1000 steel pipeline were laid. The entire route of the pipeline runs on the side of a mountain along a forest road which runs next to the body of water over a distance of around 3 km from the catchment to the powerhouse. The amount of space available proved to be very constricted. In some places, the slope had to be worked up to a height of 20 m. Sections of loose rock alternated with craggy areas and crossings of small tributaries. In order to confine the cutting of the hillside to a reasonable limit, in large areas just a trough was dug out to produce a constant longitudinal gradient for the pipeline. In order to achieve the coverage of the pipeline required to ensure that it could be operated without any impact from frost, a partition was constructed between the road and the pipeline using gabions or wooden plank walls and this was backfilled with excavated material. This labour-intensive solution was implemented with the assistance of workers from the surrounding area.

even deeper has a grated maintenance walkway fitted over the entire width above the level of the water. This means that the sluice and the hydraulic equipment are easily accessible. The only thing that can still be seen today is the entrance door. Passersby have no inkling of the construction volume below the ground. The catchment is configured to be accessible for living organisms in the body of water via an industrial fish ladder, with the concrete walls having been clad with natural stone in order to improve their appearance. As a general rule, the developer, Sergej Kovach, and his manager for the dedicated construction sector, Yuriy Korolychin, placed maximum importance on a clean finish and creative design with the minutest of detailed touches. TURBINE LIKEWISE FROM SOUTH TYROL Operating in the powerhouse is a vertical 4-nozzle Pelton turbine from the company Troyer which delivers a maximum output of around 1 MW and was supplied by Markus Wild as part of his overall assignment. This also includes the Hitzinger synchronous generator, the transformer, the control equipment, the low-voltage installations and the medium-voltage installations as well as the pipelines leading to the catchment and the control panel for the catchment installed in the pressurised retaining basin together with a small transformer. The power supply for the catchment area was deliberately designed to be stronger because as a result it was also possible to simultaneously supply power to a nearby holiday home. With regard to the previous experiences that the power plant operators gained with different models of turbine from a variety of different sources, for the Shypot II power plant they decided to place their trust in the reliably robust and powerful technology of one of the most innoNikolai leading assembler Ukraine, Ezio leading assembler Wild Metal, Yuriy director of the building sector, Sergiy Kovach Owner / Client

The feed water is directed via 9 Grizzly 1000 modules and underneath the fish passageway through to the underground pressurised retaining basin.

photo: Wild Metal

INNOVATIVE SLUICE DESIGN For the construction of the water catchment, the body of water was routed past the side of the construction site using steel pipes. The feed water with a design discharge capacity of approx. 900 l/s is captured using 9 Grizzly 1000 modules and directed underneath the fish passageway through to the underground pressurised retaining basin. On the orographical left-hand side a sluice gate for the upstream basin was installed and, with a cylinder recessed in the double protective plate, this represents another innovative solution from the company Wild Metal. Apart from the opening in the concrete on the front of the new barrier, none of the sluice gate is visible. For the base excavation of the construction pit for the pressurised retaining basin, it was necessary to dig down to a depth of more than 12 metres. The pressurised retaining basin with an outgoing pipe placed

The penstock is made from welded steel pipes

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photo: Wild Metal

HYDRO

The vertical 4 nozzle Pelton turbine from Troyer is designed for 1 MW capacity.

vative companies from the Alpine region â&#x20AC;&#x201C; in the technology of Troyer AG from the town of Sterzing in South Tyrol. The high-quality runner is milled from a stainless steel monoblock, and the design of the turbine mirrors the state of the art in hydropower technology. It is a high performance turbine to ensure efficient and reliable operation for many decades. The extremely smooth running coupled with strong efficiency data right across all operating points reinforced the operators' conviction that they had made the right choice. Ultimately, the reference installations that they had visited in the Alps before they made their decision offered an extremely persuasive argument. For the experienced hydro power specialists from South Tyrol, who also boast a

May 2015

great deal of experience in foreign markets, the assignment from the Ukraine also represented uncharted territory. However, with the turbine that was supplied, Troyer AG was able to impressively demonstrate that it can stand the test in North-East Europe very well. COMMITMENT WITH A SOCIAL BENEFIT The facade of the new powerhouse has a unique character of its own thanks to the sensitive design incorporating traditional and modern elements. It stands comparison with the most modern plants in the Alps from both a technical and visual point of view. The company Kommertsconsult is planning in the future to become involved with as broad a range of sources of renewable energy as possible. To this end, a kind of group struc-

Technical adviser DI Dengg Adolf (left) and Ezio Zandonella Maiucco inspecting the fish ladder

ture with the name RENER is being created. One subsidiary will push ahead with projects in the area of providing energy from biomass. Another very important aspect for the company is implementing social compensatory measures alongside the projects. For example, a kindergarten has already been built in the community in which the next hydroelectric power plant will be constructed. Another primary concern for the developers is that, in addition to the workers from their own construction division, they should also strive to employ people from the local area surrounding the project and then subsequently get them involved in operating the plant. And not least in underdeveloped regions the people are able to enjoy a certain independence in respect of their power supply.

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Combining sustainability and economics was the main goal for the new Turrachbach power plant, which was put into operation in December 2013 in the Styrian village of Predlitz. Fürstlich Schwarzenberg'sche Familienstiftung Vaduz, the family foundation operating the power plant, counted on perfect technological and thoroughly planned solutions to guarantee a reliable power plant operation for the next decades. The installed OSSBERGER cross-flow turbine will on average produce about 5.4 GWh of clean electricity a year from the power of the Turrachbach creek. With this power plant the operating company again sets an example in working sustainably with natural resources.

ron was the resource that kept the economy of the Styrian village of Turrach – which has since changed its name to Predlitz-Turrach – running for centuries. In the mid 19th century the annual iron ore production was 6,000 tons, which earned the mining industry of Turrach an international reputation. Turrach's standing was not least achieved through the first usage of the Bessemer process on the European continent in 1863. Nevertheless, the area's economy declined in the following four decades. The small factory in Turrach had no chance of competing with the early large-scale iron extraction industry. All branches of the local industry - iron extraction, steel production and ore mining – were shut down in 1906. The power house was built in a narrow point of the valley.

“Considering the fact that the iron industry always depended on energy supply, which was at first provided through lignite, we may speak of Turrach as a village where energy production has a long tradition,” Michael Sterneck, diploma engineer and director of Schwarzenberg'sche Familienstiftung Murau, explains. The company's main business is agriculture and forestry and it administers 20,000 hectares of forest. In the last couple of years the company has added another branch of energy recovery: hydropower. “We are very much bound to the concept of sustainability. Our aim is to use the potential of our natural resources rationally. Therefore hydropower was and still is an important option.” CERTAIN CREEKS EXCLUDED A few years ago Schwarzenberg'sche Familienstiftung commissioned planning agency PITTINO ZT GmbH, based in Graz, Styria, to perform a comprehensive potential study to explore all possibilities for hydropower projects on the company's grounds. Mr Sterneck says: “One major objective was to set up an environmentally friendly project and from the beginning we agreed not to use waters whose natural terrain was, from our point of view, to be protected. On the one hand we excluded certain creeks, on the other hand we focused on waters that required less

photo credit: zek

The water catchment at the Turrachbach in Styria.

May 2015

photo credit: zek

AUSTRIAN TURRACHBACH POWER PLANT IMPRESSES WITH SUSTAINABILITY

protection or already featured some buildings – and therefore provided an appropriate location for a hydropower plant.” The research soon showed first results within the following years. Two small-scale hydropower plants with an annual output of about 1.8 GWh each were built. With these plants the operators gained a lot of experience which would again have an influence on the following project: the Turrachbach power plant. But before the project could be launched an economic basis had to be established. MEETING HIGH QUALITY STANDARDS With the commissioned planning agency having conducted comprehensive variant studies, a solution for both high-quality design and economic execution was found. The Turrachbach power plant was conceptualized as a medium-pressure power plant using a maximum of 3,000 l/s from the Turrachbach to produce electricity. The structure is mainly that of a weir structure with a 17 m wide steel fish belly flap gate, a bottom outlet and a side channel through which the process water reaches the double-chamber sedimentation basin. From there the water flows through a 2,570 m long penstock to the power house, which was built in a narrow point of the valley directly onto a precipice.

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phto credits: zek

HYDRO

OSSBERGER's cross-flow turbines excel at simplicity and robustness. The installed top-performing machine unit in the Turrachbach power plant is designed for an output of 1.63 MW and on average produces 5.4 GWh of clean electricity a year.

ADVANTAGES OF CROSS-FLOW TURBINES The design of the penstock was just as important as choosing the right turbine. “We reflected for quite some time on the most reasonable choice of machine type. Eventually we decided that a cross-flow turbine by OSSBERGER would be the ideal solution,” says director Michael Sterneck. “It is important to mention that we are not an energy supply company. Our forestry staff have neither electrical nor mechanical engineering know-how and are not trained to work with complicated hydropower machine units nor to react in precarious situations. For this reason we decided on an uncomplicated turbine, which has repeatedly proved valuable and robust at the same time.” But the turbine with the cylindrical runner offered even more advantages. The common arrangement of the guide vanes on 1/3 and 2/3 of the breadth allows a simple adaptation to the water flow. The smaller runner chamber operates with minor quantities of process water, while the larger chamber uses medium quantities of water and in case the water flow exceeds the medium level both chambers are employed. The cross-flow turbine is simple to control, withstands sediments and debris in the process water and excels through a high part-load efficiency. With its reliability and excellent degree of efficiency regarding the part-load operation the turbine qualifies for strongly deviating flow patterns, which torrents, such as the Turrachbach creek, show throughout the year. The turbine is designed for a flow rate of 3,000 l/s and

a gross head of 71.10 m. It attains an output of 1,630 kW. The low rotational speed of the turbine is transmitted through a gearbox to the generator's rotational speed of 1,000 rpm. The synchronous generator has a nominal output of 2,029 kVA. A HARMONIOUS PROJECT FROM ESTHETICS TO ECOLOGY In December 2013 the machine unit was commissioned. It supplies the electrical grid with an annual average of 5.40 GWh and thus is the power plant with the best performance and the highest output of Schwarzenberg'sche Familienstiftung. The plant bears the seal of a company that pursues the necessary economic aspects and focuses on its commitment to sustainability and social responsibility. “Of course, we want to be commercially successful with projects like this. But we also want to obtain results that are well accepted by the people. The projects have to be harmonious in every sense, from their esthetics to their ecology,” says Mr Sterneck. The rates for electricity from hydropower are currently low in Austria, affecting the profitability of a top-performing hydropower plant. Longterm planning is inevitable in this context. “We are used to planning for the long term, which we have learned from our history in the forestry industry. Hence, it is not important to us if a project like a hydropower plant amortizes after 15 years or after 18 years. We focus more on solid and environmentally friendly structures,” Mr Sterneck explains.

Technical Data w

Flow Rate: 3000 l/s

Net Head: 67.50 m

Turbine: Cross-Flow Turbine

Manufacturer: Ossberger

Turbine Rotation Speed: 324 rpm

Output: 1727 kW

Generator: Synchronous Generator

Generator Output: 2029 kVA

Rotation Speed: 1.000 rpm

Fish ladder: Vertical Slot pass

length: 40 m / 15 pools

penstock length: 2646.3 m

Material: GF-UP & duct. cast

planning: PITTINO ZT GmbH

Annual Energy Capacity: 5.40 GWh

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HYDRO

photo credits: Energiedienst

RYBURG-SCHWÖRSTADT POWER STATION INVESTS MILLIONS IN ENVIRONMENTAL IMPACT IMPROVEMENTS

The annualy mid-value production at the Ryburg-Schwörstadt border power station is around 760 GWh of green electricity. Earnings are split 50% between Germany and Switzerland.

Ryburg-Schwörstadt power station is situated right on the border between Germany and Switzerland and was built between 1926 and 1931. A power output of 120 MW makes this plant the largest hydroelectric station on the High Rhine. In 2010 the respective authorities granted the operators a license for another 60 years. This was linked to a total of 17 compensatory measures designed to achieve a positive long term effect on the plant’s environmental impact. The most elaborate measure was the integration of a new 1.2 kilometre fish pass. At the same time a downstream water discharge power station was also set up by the fish pass, enabling the ecological measure to generate additional energy.

RULES AND REGULATIONS Overall, the authorities and associations in charge agreed 17 measures with the power station. Ryburg-Schwörstadt AG invested around 20 million Swiss Francs in implementing the catalogue of measures which included expanding the swamped up zones, creating flat bank areas and the construction of a pedestrian crossing at the power station.

May 2015

The most complex building step that created the greatest ecological benefit was the integration of a new fish pass. This 1200-metre watercourse ensures all the local fish can swim around the power station safely. Research showed the ideal water speed for encouraging fish to swim upstream on this section of the Rhine was 6 m³/s. After around 800 metres the bypass watercourse has to navigate a steep height difference of a maximum of 10.6 m, so from this point onwards the planners integrated a flowreducing rough surface fish pass. Since the stone block step construction fish pass wouldn’t be able to stand up to the 6 m³/s, the decision was made to redirect 4.6 m³ of this water along a pressurised underground pipeline (DN 1800) to a newly built power station able to exploit the energy potential of the redirected water. TURBINE RUNS SMOOTHLY EVEN WITHOUT OIL Once the protracted licensing negotiations had been completed, construction work on the fish pass and the downstream power station finally commenced in 2012. ‘Since the pressurised discharge line had to be run under a new rough surface fish pass, part of the way, all building work had to be started parallel. One practical benefit was that the excavation work for the pipeline was used to

model the fish pass’ recounted Beat Karrer.In the actual powerhouse power is generated by a doubly-regulated Kaplan pipe turbine made by the German manufacturers Wiegert & Bähr. In the planning phase, due to the large changes in the water level of the Rhine, this type of turbine was considered the best choice. Furthermore, the efficiency level of a doubly-regulated Kaplan machine can be adapted very well to suit the entire range of discharge volumes and speeds. The bearing of the turbine shaft is lubricated with station water and does not require oil. photo credits: Wiegert & Bähr

he section of the Rhine that flows between Lake Constance and Basel is known as the High Rhine and forms a natural border between Germany and Switzerland. It was necessary to meet the regulative expectations of two countries, since the Ryburg-Schwörstadt power station occupies land on both sides of the border - BadenWürttemberg in Germany and Aarau canton on the Swiss side. This was also why the initial planning and environmental impact reports required for an extension of the license were compiled in 1996. Managing Director Beat Karrer explained the hurdles involved in being relicensed: ‘The application for an extension of the license was finally submitted in 2007. Although it took a long time to be granted an operating license because the various offices had to come to a consensus and agree a joint approach, we were very well prepared. Fortunately, there weren’t any extreme difficulties or objections’.

Synchronised generator and turbine are ideally situated for servicing tasks.

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It can generate 351 kW, and revolves at 430 rpm. Annually it is estimated around 2.5 GWh of clean electricity can be produced. A technician from Ryburg-Schwörstadt power station was on site the whole time the turbine was being assembled at the Wiegert & Bähr production base. In this way he was able to gain the best possible insight into the functioning of the machine and to familiarise himself with every individual component. The adaption and fitting of the turbine and the shut-off valve in the compact power house was a particularly tough challenge for the turbine builders. Utmost priority was given to ensuring the interior of the machine was accessible for future maintenance work. Optimum maintenance-friendliness was achieved as the arrangement of the turbines in the power house was agreed upon in cooperation with the allocated planners from Dr. Rolf-Jürgen Gebler civil engineering office, who were also responsible for the planning of the bypass watercourse. EVERYTHING FROM A SINGLE SOURCE In addition to the turbine, Wiegert & Bähr were also responsible for all the structural steel construction for the new downstream discharge power station. This included the installation of a swinging gate of 3.16m in width and 2.24m in height at the in-flow end of the new bypass watercourse. The gate is driven by a linear actuator and regulates the amount of water flowing down the fish pass. W&B engineers also installed two new inlet rakes with the accompanying rake cleaning systems. The first rake was 4.5 m wide with a rod length of 3.71 m and a rod-to-rod distance of 15 mm. It was mounted to the turbine by the distributor. The second inlet rake is mounted to the dividing pillars between the machine room and weir. From this position additional water was directed to the end of the dividing pillar to encourage the fish to use the pass, where another two points of entry are located. The fish swim via the central pillars to a vertical slot fish pass that is linked up to the bank-side rough surface fish pass. The trash rack cleaner of the separator rod system also features a 15 mm rod gap. However, at a width of just 1.84 m and a rod length of 2.89m it is considerably smaller than its counterpart. ‘The removal of driftwood and flotsam from the rakes is done by two large and identical tooth-comb cleaners driven by an electromechanical engine. Similarly, when constructing the swing gate the decision was made not to use a hydraulic drive to avoid the need for oil and grease’ said Markus Rest, head of construction at Wiegert & Bähr, expanding on the system’s advantages. The rise and fall speed of the trash rack cleaner can be selected and is controlled via the adjustable frequency converter, which also ensures the systems can be started and stopped gradually. Constant pressure is exerted by the trash rack cleaner on the rake due to the use of an electric linear motor and a set of pretensioned springs.

photo credits: Wiegert & Bähr

HYDRO

Assembly of the double-regulated Kaplan tube turbine.

IT PAYS TO INVEST The new discharge water power station has been in operation since the 1st April last year. Beat Karrer, CEO, is very pleased with the progress the project has made: ‘The fish accepted the ladder immediately, the turbine is running smoothly and there is a large degree of acceptance from the local people and environmentalist associations. It’s working in everyone’s favour and it was a good idea to involve all parties in the discussions’. In total Ryburg-Schwörstadt AG power station management has ploughed over 20 million Swiss Francs into this large-scale project and within 3 years has been able to meet every one of the 17 licensing conditions. As well as being of benefit to the environment, these investments are helping to boost the local and regional economies along and beyond the High Rhine, since a large proportion of the building work was carried out by companies based in the region.

TECHNICAL DATA • Design Flow: 4,6

m³/s

• Net Head: 8,84 m

• Machine: Kaplan, doubly-regulated

• Manufacterer: Wiegert & Bähr

• Runner Speed: 430 rpm

• Turbine Output: 351 kW

• Generator: Synchronous

• Manufacterer: AEM

• Nominal Apparent Output: 430 kVA

• Nominal Voltage: 400 V

• Average Energy Capacity: 2,5 GWh

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The island state of Sri Lanka has quite a long history of hydropower utilisation. This is one of the reasons why the quality of hydropower machines from the alpine region are highly appreciated here. For years, Upper Austrian hydropower specialist GLOBAL Hydro Energy GmbH has been contributing to the high reputation of Austrian technology on the Sri Lankan hydropower market. With 19 installed hydropower plants under its belt, GLOBAL Hydro is now one of the industry’s leading providers of hydropower solutions. The most recent project was completed last year in the central province of Matale on the Sudu Ganga. GLOBAL Hydro not only provided the electromechanical equipment for the new low-head power plant, but also installed the entire hydraulic steelwork. With the handover to the customer, the project was successfully completed last October.

n Sri Lanka, hydropower constitutes the most important form of electrical energy. Almost half of the entire electrical energy in the national grid is supplied by the hydropower plants that are distributed across the entire island state. Although the market for largescale hydropower has by now reached its limit due to the lack of available sites, the Indian Ocean state with its 103 rivers still offers a sizeable growth potential in terms of small hydropower. Recently, the Sri Lankan government has made it quite clear that they intend to exploit that potential. A new law was passed already a few years ago that allows private enterprises to build power plants as well. One of the firms taking advantage of this opportunity is Ross Hydro Power, whose owner is in the concrete and tiling business. Since 2010 Ross had been planning a small-hydropower plant on the Sudu Ganga in the central Sri Lankan province of Matale – and obtaining the required planning permission.

explains project manager Thomas Kuffner of GLOBAL Hydro. For him and his team, the location was anything but “terra incognita”. After all, a few years earlier GLOBAL Hydro had been supplying turbines for hydropower plant Rajjammana some 15 km downstream. As the contract for the electromechanical equipment and hydraulic structures had been awarded to the Upper Austrian hydropower specialists already in March 2012, the first excavators arrived at the site already in June. However, the first year of construction work was marked by a considerable setback: In December 2012, a once-in-a-hundredyears high-water flooded the entire construction site. Spilling over the riverbed, the Sudu Ganga quickly destroyed part of the existing basic structures, leaving damage, increased construction costs and a delayed project schedule in its wake.

photo credit: GLOBAL Hydro

TURBINE SPECIALIST PROVES HYDRAULIC STEELWORK ENGINEERING COMPETENCE After this incident, the construction project was spared any further catastrophic events, so that the power plant facility slowly began to take shape in 2013. In March 2014, it was finally time for the GLOBAL Hydro engineers to step up to the challenge – a challenge that would test them to their limits. One reason for this was the climatic

photo credit: GLOBAL Hydro

FAMILIAR HYDROPOWER TERRAIN FOR GLOBAL HYDRO The site was not virgin territory as far as hydropower projects was concerned. “Previously, there used to be a small power station there, around a hundred years old, with just one turbine. However, none of the original structures could be salvaged for reuse in the new project,”

GLOBAL Hydro delivered the two powerful machine units to Sri Lanka. The two identically constructed vertical Kaplan turbines are designed for a capacity of 2,421 kW each.

Hydropower plant Ross is situated on the Sudu Ganga in one of Sri Lanka’s central provinces.

The Upper Austrian hydropower specialist also provided the entire hydraulic steelwork for the facility.

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photo credit: GLOBAL Hydro

UPPER AUSTRIAN HYDROPOWER SPECIALIST STRENGTHENS MARKET POSITION IN SRI LANKA

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photo credit: GLOBAL Hydro

HYDRO

With 19 small-scale hydropower projects completed in Sri Lanka so far, GLOBAL Hydro is among the island state’s market leaders.

The durable hydropower technology provided by the Austrian manufacturer is essential to ensuring reliable plant operation.

conditions, another was the fact that with this project the team was venturing into new hydraulic engineering territory. After all, the contract included not just the turbines, generators and gearing boxes, but also the coarse and fine racks, intake gates, trash rack cleaners and flushing gates. Both the construction and on-site installation requirements posed new challenges to the GLOBAL Hydro engineers and technicians – a test of their abilities, however, that they passed with flying colours. “Although Sri Lanka boasts an extensive hydropower infrastructure, it’s still quite difficult to find the proper heavy-duty equipment that’s required for installation work. This was an issue, especially when we were supposed to install the hydraulic steelwork engineering equipment,” says Thomas Kuffner, explaining why this can sometimes cause project delays in the Far East. “Lack of appropriate tools or equipment often is a real problem in Sri Lanka,” he says. Getting the gate operating mechanism to the construction site was not easy either. Since it had to be transported in its pre-assembled state, a heavy

haulage vehicle was needed, and arranging for one turned out to be a real challenge. SMOOTH COMMISSIONING Despite all these obstacles, the installation and commissioning work went smoothly without any further incidents. On September 16th last year, the two Kaplan pit turbines were spun up for the first time. With the trial operation in full swing, hydropower project Sudu Ganga entered its final phase. Conceptually, the facility is a low-head power station with a maximum flow capacity of 60 m3/s. By way of a lateral intake, the water is split into two non-pressure channels and flows past the fine racks to the turbine chamber. The generously dimensioned power house is home to two vertical Kaplan turbines, which are designed for a maximum head of 9.6 m and a design flow rate of 30 m3/s each. The nominal speed of the turbines is 177 rpm. An Eisenbeiss gearing increases this rotational speed to an operating speed of 750 rpm. This

is the required drive speed for the synchronous generators by Hitzinger, which have a nominal capacity of 2.9 kVA. Both the generators with their gearing assembly and the hydraulics with the regulating mechanism were included in the scope of GLOBAL Hydro’s delivery. A WELL-ESTABLISHED BRAND ALSO IN THE FAR EAST For the constructors, HPP Ross marked their first hydropower project so far. For Austrianbased hydropower specialist GLOBAL Hydro, it was the nineteenth project of this type in the Southeast Asian island state. This makes the Upper Austrian provider the undisputed market leader in the Sri Lankan hydropower market. Where market performance is concerned, is not just the high quality of the equipment that sets GLOBAL Hydro apart, but also their superior reliability and flexibility, which has enabled their success in this local hydropower market. The new hydropower plant Ross may serve as a case in point.

Today, the operators in Sri Lanka are proud of their new small-hydropower plant. Pictured in the centre is Project Manager Thomas Kuffner.

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Flow Rate: 60 m3/s Net head: 9,0 m Turbines: 2 vertical Kaplan turbines Manufacturer: GLOBAL Hydro Energy Nominal runner speed: 177 rpm Output: 2421 kW (each)

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Gear boxes: 177 rpm / 750 rpm Manufacturer: Eisenbeiss Generator: synchronous generator Manufacturer: Hitzinger Output: 2900 kVA Voltage: 690 V Overspeed: 1850 Upm Control system: HEROS

photo credit: GLOBAL Hydro

Technical Data

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The Lixhe hydro-electric power station on the river Meuse is Belgium’s biggest running-water power plant. As the four single regulation Straflo turbines did not facilitate flexible operation, two of them were replaced by state-of-the-art double regulation Kaplan Bulb turbines. The nominal output remained unchanged.

photo credit: EDF Luminus

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TURBINE REPLACEMENT ENHANCES VERSATILITY OF BIGGEST RUNNING-WATER POWER STATION IN BELGIUM The Lixhe hydro-electric power plant is situated some 10 kilometres south of Maastricht, not far from the Dutch and German borders. Currently operated by the Belgian electricity supplier EDF Luminus, the plant commenced operations in 1980. It was originally equipped with four identical Straflo turbines with horizontal axes. Their poor control characteristics, however, turned out a weak point with regard to the modern, adaptive operation of the power station. This is why as part of an elaborate construction project, two of the four Straflo turbines were recently replaced by double regulation Kaplan Bulb turbines from ANDRITZ Hydro. Meanwhile, Belgium’s biggest running-water power station has recommenced operations with all its generators. All thanks to its newly obtained flexibility, it is proving its worth in everyday service.

n the historical development of hydroelectric power in Belgium, 1980 was a year of great significance. With the Andenne and Lixhe power stations, two modern production plants commenced operation on the Meuse River. On average, they have jointly been providing some 96 GWh of clean electricity per year to the Belgian power grid. For a country on place 104 in the global ranking of installed hydro-electric capacities, these are two highly significant base load renewable energy producers. The Lixhe power station is even considered the most powerful running-water hydro-electric facility in all of Belgium. What the two plants had in common aside of the time they were built was their basically identical electromechanical equipment. Until

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2013, Straflo turbines were the only design used in both the Andenne and Lixhe stations. The Andenne station had three with 3.05 MW each, while the Lixhe station featured four with 4.5 MW each. At the time, Straflo turbines constituted a highly advanced form of low-pressure turbine with an outstandingly short design as its key advantage. This significantly lowered erection costs. In the Lixhe power station, savings due to the reduced building volume amounted to 15 percent. There is, however, a downside to this. STRAFLO – A DESIGN WITH WEAKNESSES “With regard to its flexibility and its control characteristics, Straflo turbines have a clear disadvantage. As this hydroelectric set only features single regulation, its operational

range is comparatively narrow: Below 70 percent admission, it shows a steep decline in efficiency and it should be detached from the grid“, explains DI Martin Reisser from ANDRITZ Hydro in Ravensburg, Germany, adding, “There has indeed been an attempt to build double regulation Straflo turbines. As far as I know, two of these hydroelectric sets were deployed. Unfortunately, though, they did not function properly. There is a simple reason for this: Nobody ever found a practicable way to keep the pitch of the runner blades and that of the guide vanes aligned. This resulted in uneven operations which invariably entails cavitations. This is why in the end this concept was abandoned. Generally speaking, the classic Straflo turbine will not prevail because in addition to its poor regulation

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photo credit: ANDRITZ

A 4 MW synchronous generator during acceptance procedures at the ELIN Motoren plant in Weiz, Austria. Martin Heutele, ANDRITZ Hydro, Anne- France Fontaine, EDF Luminus, Mr. Jean-Luc Fagnoule, EDF Luminus, Thomas Taferner, ELIN Motoren

INFLEXIBLE OPERATIONS ACCOUNTS FOR UPSURGE ISSUE People in charge at EDF Luminus are quite aware of this disadvantage. “We regularly have to replace the sealing strip, and that is far from simple,” says Anne-France Fontaine, who conducted the alteration activities at the Lixhe power station. It was a bit of a foretaste to the extremely laborious retrofit of the Lixhe power station that was to follow. In 2009, the operators were confronted with new guidelines. They were required to carry out studies with regard to the power station’s passability by fish, and they had to get a grip on its upsurge issue. As the latter was without a doubt quite obviously a direct result of the poor regulation characteristics of the four Straflo turbines, their replacement – at least in part – suggested itself. “In everyday operations, we were forced to turn off the hydroelectric sets whenever the upstream head dropped below the 70 percent mark. Consequently, the upstream head naturally began to rise again. After the turbines returned to ser-

vice, it dropped again. This led to the undesired surges we were required to reduce or eliminate in guidelines from the public authorities,” says Anne-France Fontaine. REDUCTION IN CAPACITY Subsequently, EDF Luminus, Belgium’s biggest operator of hydro-electric power stations, commissioned extensive variation studies. As the most economically viable solution, these studies suggested to replace two of the four

photo credit: ANDRITZ

characteristics, it comes with another drawback: In case of runners with big diameters like here at Lixhe where the diameter is 2.6 metres, the tips of the runner blades can reach an enormous tangential velocity. The immediate proximity of the rubber seal increases the chance of small leakages. In practice, related maintenance work will in most cases be unavoidable.”

Straflo turbines by double regulation Kaplan Bulb turbines. “The installation length of the installed Straflo hydroelectric sets is particularly short. This prevented the installation of equally-sized double regulation Bulb turbines at the same positions. It was only possible to install machines with a smaller diameter. In the end, two Bulb turbines with a 2.6 m diameter replaced pre-existing Straflo turbines 3.5 m in diameter. As a matter of course, this also means a reduction in capacity and conse-

The two identical Bulb turbines with a 3.035 MW power rating for the Lixhe power station awaiting transport to Belgium at the ANDRITZ Hydro plant in Ravensburg, Germany.

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photo credit: zek

DESIGN CHALLENGES Following the approval by EDF Luminus for the refurbishing project in 2011, the contract for the electromechanical equipment was awarded to ANDRITZ Hydro in Ravensburg, Germany, in the autumn of 2012. The main challenge for the experienced turbine makers was to design the two new turbines such that they can be fitted between the existing head and tail water stop logs. In preparation of this, an in-depth survey of the installation situation had been carried out earlier. For this, the ANDRITZ Hydro design engineers not least also elaborated a 3D analysis that allows various views and sections. Finally, the Bulb turbine was designed to match a 6.61 m net head and a nominal discharge of 51.0 m3/sec. The 4-blade runner turns at 176.47 rpm and has a nominal power output of 3.035 kW. Aside of the electrical equipment supporting the turbines, the two directly coupled generators were also included in the package supplied by ANDRITZ Hydro. They were made by the Austrian manufacturer ELIN Motoren who has a century-long tradition in building generators for hydro-electric power stations. Their nominal

Demolition work as preparation for the installation of the two new hydroelectric sets.

The 4-blade runner is the heart of the new Bulb turbine.

apparent output is 4.070 kW. They are cooled by the passing water flow which is another benefit they have over the strictly air-cooled Straflo turbines. CONVERSION DURING OPERATION “Due to the aforementioned dimensional differences, it is tremendously difficult to design a double regulation turbine to fit into the existing cavity of a Straflo turbine“, says Martin Reisser. His opinion is supported by the Belgian project manager: “It is invariably more difficult to convert an existing power station than to build a new one from scratch. But this project really was a great challenge for all involved. First, numerous requirements from the authorities had to be fulfilled. Quite naturally there were issues in the field of statics and ultimately of construction logistics as

As part of the conversion work, all of the control and communication systems were replaced as well. The two remaining Straflo turbines were upgraded from the original equipment based on relays to current digital technology.

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Runner Installation. Each turbine weighs some 40 tons.

photo credits: ANDRITZ

quently a performance reduction at full load. While the original hydroelectric sets had a power of 4.5 MW each, the new turbines are rated at 3.035 MW. Had we replaced all four generating sets, overall output would inevitably have dropped. By replacing only two of the turbines, we managed to keep production at the same level while at the same time achieving the operational flexibility required“, the project manager summarises. Along with the replacement of the electromechanical equipment, modernisation of the control and communication systems was on the agenda as well.

well. After all, times were when numerous people from many companies were ‘roaming’ the construction site“. Implementation work commenced in June of 2013 with the removal of the two Straflo turbines. An important aspect of the project organisation was to keep the two remaining turbines in operation in parallel with the ongoing work. This was not possible during the dismantling. Particularly the demolition of the concrete structures caused vibrations that could have had detrimental effects on the two Straflo turbines. In the subsequent project phase during which the entire electrical equipment of these turbines was replaced, they were quite obviously also turned off. “Generally, we have tried to keep the two Straflo turbines in operation whenever possible“, says Anne-France Fontaine. STUMBLING BLOCKS ALONG THE COURSE OF THE PROJECT In order to protect the two generating sets from the dust produced by the conversion work, an XXL-sized curtain was put up. Not with the desired success, though. Fontaine: “Unfortunately, this did not work quite as well as we had imagined. Owing to the fact that the old generators are air-cooled, we could not fully prevent a little dust from getting through to the generators. After a while, the dust settles in the stator and has adverse effects on the efficiency“. This was not the only issue the project team was confronted with. Another stumbling block was the old overhead crane. This crane was well designed to take the weight of the new machinery and had been successfully tested with 40T loads in presence of a notified body prior to star-

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The 4-blade runner turns at 176.47 rpm and has a nominal power output of 3.035 kW.

ting the project. Unfortunately this crane was old and had already „suffered“ during installation of the machines in 1980. The maintenance and repair works during the course of the project were so costly and time-consuming that it was finally replaced by a brand new one. Another challenge was the construction of the two downstreampipes. It was decided to build these using timber formwork. A decision that Anne-France Fontaine and her team would not make again: “This made it very laborious and excessively complicated. If I had to do it again, I would opt for a metal variant“, the project manager confirms. ELECTRICITY PRODUCTION AS OF AUGUST, 2014 In March of last year, preparatory construction work had finally reached such a state that the first of the two turbines could start its long journey to Belgium from the ANDRITZ production plant in the Southern Germany. Following its arrival on site, the experienced ANDRITZ Hydro installation team proved that the excellent reputation it enjoys is well justified. With a lot of sensitivity yet target-oriented and quick, they completed the installation of the first turbine. In retrospect, Anne-France Fontaine confirms this: “Co-operation with ANDRITZ Hydro was indeed excellent. We could rely on a high level of workmanship quality and between their people and ours, everything worked out just fine“. In August of 2014, the new generating sets in the converted Lixhe power station finally started producing electricity. This marked an historic milestone for Belgium’s biggest running-water hydro-electric

Technical Data w

Design Flow: 272 m3/s

Turbines: 2 Straflo-Turbines (1979) + 2 Kaplan-Bulb-Turbines (2013)

Straflo-Turbines: Ø : 3.55 m

Nominal Output: 4.5 MWeach

Kaplan-Bulb-Turbines Ø : 2.6 m

Nominal Output: 3.035 MWeach

Runner speed: 176.47 rpm

Number of Blades: 4

Manufacturer: ANDRITZ Hydro

Weight : 40 t each

Generatores: 2 synchronous gener.

Manufacturer: ELIN Motoren

Apparent output: 4’070 kVA

Current: 6.0 kV

Average Energy Capacity: 61 GWh

Head: 6,95 m

graphics: ANDRITZ

photo credit: ANDRITZ

In preparation of the conversion project, ANDRITZ Hydro design engineers performed in-depth 3D analyses. Performing the conversion from a Straflo turbine with its singularly short dimensions to another, longer turbine design such as a Bulb turbine is particularly challenging.

facility, even though conversion work had not been completed yet. Currently, the last batches of work are in their final stages while extensive operational tests are carried out. “At this time, all operational conditions are being tested through their paces. Additionally, the optimal operating points are determined and fine-tuned“, says the project manager. She and her team are now drawing a positive balance of the conversion project that came with many challenges for all involved. The operators confirm that they are very satisfied with the efficiency of the turbines and with the high flexibility of the power station’s regulation that has been achieved at last. At a nominal water flow of 51.0 m3/sec. each, the generating sets can stay online at works water volumes as low as 15 m3/sec. with no problems. This constitutes the foundation on which the new Lixhe power station can now ensure constant head and tail water levels. EYES ON THE NEXT PROJECT TThe rich experience gained during this conversion project is expected to pay off in the near future. The Lixhe power station will not remain the only EDF Luminus plant to be converted, after all. In the next few years, conversion of the Andenne power station is top on the agenda of Belgium’s second biggest electricity supplier. The plant is situated some 30 kilometres upstream from Lixhe and is also still equipped with Straflo turbines, of which it has three. Before long, two of them are planned to be replaced by state-of-the-art double regulation Kaplan Bulb turbines. That the operators will again rely on the proven quality supplied by ANDRITZ Hydro is almost a matter of course. A lot of know-how gathered in the Lixhe project will in any case be reused for the upstream hydro-electric station in Andenne. And the waves near the Belgian border to the Netherlands will likely soon altogether be a thing of the past. Some ten percent of the overall electricity generation capacity installed in Belgium – slightly more than 2,000 MW – are contributed by EDF Luminus who like to view themselves as “first challenger“ of Belgium’s biggest electricity supplier. Renewable resources such as wind and water account for 200 MW or ten percent of this capacity. With 73 MW installed hydro-electric power, EDF is the biggest operator of hydro-electric power stations in the country, producing electricity in seven big running-water power stations on the rivers Meuse and Sambre. The Brussels-based power company currently employs some 1,000 people. Its main shareholder is the French electricity corporation, EDF, holding 63.5 %. May 2015

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Picture: zek

The new turbine house of hydropower plant Steigs Mels was relocated underground towards the outer perimeter of the former textile mill’s premises. The three twin-nozzle Pelton turbines were replaced by a 6-nozzle Pelton turbine by Andritz Hydro.

TEXTILE MANUFACTURER STOFFEL’S HYDROPOWER PLANT IN MELS SHINES IN NEW SPLENDOUR Swiss-based textile mill Stoffel Mels closed its operations after 125 years of business. SAK (St. Gallisch-Appenzellische Kraftwerke AG) won a bid for the entire site, which includes a hydropower plant, in 2007. Together with the community of Mels in the canton of Saint Gall, SAK founded “Kraftwerke Stoffel AG” and refurbished the old power plant facilities. The three twin-nozzle Pelton turbines were replaced by a modern 6-nozzle Pelton turbine by ANDRITZ Hydro. The turbine house was moved to the outer perimeter of the mill premises. Also, the intake was completely renewed, and the water path was renovated as well. Overall, the operators invested CHF14 million into the project, hoping for an output of at least 14 million kWh per normal year.

he Stoffel Mels textile mill is situated in the town of the same name in the canton of Saint Gall. The firm’s history goes back to the year 1866. In that year, Glarus-based company Heer built the textile mill in Mels. Back then, the operating license included the permission to abstract water from the river. During the following years, the hydraulic structures were installed. After many years of successful operation, even during the war, in 1995 several changes in ownership had finally brought the 125-year history of the textile mill high above the town of Mels to a close. Twelve years later, in 2007, the entire property was acquired by St.Gallisch-Appenzellische Kraftwerke AG (SAK). SAK is the leading regional service provider for power grids and energy supply in the cantons of Saint Gall, Appenzell Ausserrhoden and Appenzell Innerrhoden. Hydropower plant as a purchasing incentive

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When purchasing the property, SAK’s main focus was on making use of the hydropower plant and power generating license that came with it. A buyer for the other section of the property was sought and found in 2010. The buyer is planning for a mix of development projects, including lofts, studios, commercial buildings and restaurants. MOVING THE TURBINE HOUSE SAK kept operating the existing power station until July 29, 2013. However, SAK was already working on plans for the partial rebuilding and renovation of the power plant, together with renowned Swiss planning office Rüesch Engineering AG, of the town of Herisau. The main focus of these plans was the construction of a new turbine house in a different spot closer to the plant site perimeter. Designed as an underground construction, it will be built into the bedrock.

REBUILDING THE INTAKE In addition, the plans also called for various reconstruction measures. However, the nonpressure tunnel, water reservoir and penstock were to be reused. Construction work continued during the winter, unaffected by the weather – except in the intake area, where it was a critical factor. As a result, this area turned out to be the bottleneck in terms of project planning. “Some of the work scheduled for the winter months had to be carried out in the water,” says Ralph Egeter, Project Manager and Managing Director of Kraftwerk Stoffel AG. “But thanks to the mild weather, we were still able to complete the work on schedule at the end of March 2014.” The new intake has a wider profile and was equipped with a larger desilter. The river Seez is a veritable mountain torrent, whose water volume can rise from 1 m3/s to 60 m3/s in a very short time. As a result, it

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Photo credits: SAK

for the machine to be completely decoupled (i. e., disengaged) from the turbine house. “Our initial measurements showed sensational readings close to zero,” Egeter is happy to report. Pelton facilities are known to get very noisy at times, especially in the area of the tailwater canal. This is why the roofing of the tailwater canal at the turbine house in Steigs has been fitted on the inside with two successive noise absorbing concrete structures.

The 6-nozzle Pelton turbine by Andritz hydro was named “Angelina”. It has an output of 3.2 MW and a maximum flow capacity of 2,340 l/s.

transports a huge amount of bedload material and suspended sediment. This must be kept away from the pipework so it cannot get to the turbine blades of the new machines in the turbine house. SOPHISTICATED NOISE INSULATION Inside, energy production is now the responsibility of a modern vertical 6-nozzle Pelton turbine by Andritz Hydro. With an impressive capacity of 3.2 MW, the turbine, in combination with the 4 MVA generator by Indar,

is expected to generate at least 14 million kWh a year. The turbine was given the name “Angelina”. Another feature that sets this turbine house apart from others is its sophisticated noise insulation. It is designed to protect the neighbouring buildings against vibration. To prevent the lower frequencies – the so-called ‘structure-borne sound’ – from propagating through the bedrock to the neighbouring buildings above ground, the foundation encapsulating the machine has been coated with noise absorbing sylomere. This allowed

ELECTRICITY FOR 3,500 HOUSEHOLDS After nine months of construction, hydropower plant Steigs was ready for trial operation in mid-May. 135 years after its inauguration, a part of the Stoffel Areal has been restored to its former glory, with the machine unit in the new turbine house providing high-quality eco-power for 3,500 households. Egeter is highly satisfied with the implementation of the project: “Weatherwise, we were really fortunate, and thanks to the reliability of all contracting parties we were able to finish the project on schedule.” The official inauguration ceremony was held on June 6, 2014, followed a day later by a public opendoor event with guided tours of the entire facility. 700 people followed the invitation to pay Angelina a visit.

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photo credit: Schubert

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The new Stanzer Valley power plant is noted not just for its high technical standards, but also for having a clever participation model which enabled both local utilities and t he local communities to become joint owners of the eco-power plant.

TYROLEAN REGION OPTS FOR COLLECTIVE HYDRO POWER INITIATIVE Thanks to a clever participation model, the project enterprise behind the new Stanzer Valley power plant in the Tyrolean Oberland region is very diversified: the owners are all of the local communities in the Stanzer Valley, three Tyrolean utility companies and the project development company INFRA. This factor gave the power plant project a great deal of prestige in the region. What is more, it is regarded as a real showpiece power plant which sets standards both in organisational and technical terms and not least also from an ecological perspective. The project partners have invested around 58 million euros in the plant, which each year will generate around 52.2 GWh of eco-friendly electricity and due to its storage tunnel will be capable of supplying peak current when it is needed.

ment of the power plant is situated in the community of Flirsch. From here, the water is channelled via a headrace, which is 5.4 km long in total and includes the 4.8 km long inflow and storage tunnel, to the machine house in the community of Strengen. There it encounters three 6-nozzle Pelton turbines which together have an installed capacity of 13.5 MW. The generated power is fed from

photo credit: Schubert

the Stanzer Valley is the extension of the Inn Valley in a straight line in a westerly direction. The valley is drained by the River Rosanna, which ultimately flows as the River Sanna into the River Inn. The corresponding catchment covers an area of 205 km2. The new plant is specifically a run-of-river plant with a storage tunnel. The water catch-

The plant with the three 6-nozzle Pelton turbines is an investment for many generations. Thanks to the choice of materials, the low generator speed and the resulting large dimensions in relation to the turbine output, the turbines are designed for low-maintenance operation over many decades.

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the powerhouse via 25 kV cables into the public grid. Trial operation of the first machine began at the end of October of last year. COMMUNITIES BECOME OPERATORS The project developer INFRA had developed a participation model for the power plant project which was to prove to be pioneering. The crucial aspect was that the intention was to incorporate not just utility companies but also the local communities in the participation model. In contrast to the majority of normal power plant projects, the communities were not compensated but instead became joint owners of the power plant. This meant that it was possible to win over all four of the communities in the Stanzer Valley, as well as the community of Zams. Today the four local communities of Flirsch, Pettneu, St. Anton and Strengen each have a 6.25 per cent stake in the operating company; 5 per cent was assigned to the community of Zams. The biggest shareholder is EW Reutte with a stake of 34 per cent, a further 11 per cent stake is held by EWA St. Anton, STW Imst have secured 15 per cent and another 10 per cent stake is currently held by the project developer INFRA.

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The doping of the residual water and the fish ladder was completely decoupled from the power plant control system by the Schubert team.

There were just a couple of geological fault zones accounting for around 380 m over a total length of 4 km that slightly slowed down the rapid speed of progress of the machine. The 120 m high vertical well including a surge chamber with a diameter of 3 to 4 m was produced using what is known as the Alimak method, an "overhead breakout" which has proven its worth in underground mining for more than half a century. The bottom of the headrace tunnel was lined with tubbing segments. The total length of the discharge channel up to the powerhouse is 500 m. DN 2200 steel pipes were used as plating for the pressure shaft. MACHINES MADE IN AUSTRIA As part of the bidding process to provide the electromechanical equipment, the Tyrolean hydro power specialist offered the most persuasive choice and was commissioned to construct and deliver three vertical-axis 6-nozzle Pelton turbines of identical construction. This option represented the ideal machine solution for the general prevailing conditions. The turbines reach their optimum efficiency with a nozzle opening of 75 per cent and each produce 4.5 MW of power. Conversely, they can also be operated with a minimal flow rate of 200 l/s. Coupled directly onto the Pelton turbines, three powerful synchronous generators from ELIN Motoren GmbH were installed. These are water-cooled machines with a brushless exciter and a rated output of 6000 kVA. Each of the generators weighs 50 tonnes and the bridge leading to the location of the powerhouse had to be specially reinforced so that they could be delivered.

TUNNEL MANAGEMENT REQUIRES FINESSE FROM THE E-TECHNOLOGY SPECIALISTS Together with Geppert and ELIN Motoren, Schubert Elektroanlagen, the specialist in electrical technology and control technology from the Austrian state of Lower Austria, formed the triumvirate that was responsible for provi-

photo credit: Schubert

EATING THE WAY THROUGH THE MOUNTAIN The construction of the tunnel was considered to be the really big challenge of the construction project. The headrace tunnel was created using a tunnel boring machine (TBM) which weighed 380 tonnes and was designed to eat its way through the ground over a length of 4 kilometres. And this proceeded essentially without any major complications.

photo credit: Braun

INFRA will be provided with its shares following the commissioning of the project. In 2011, the plans for the project had already progressed to such an extent that it was possible to submit the project in the autumn of the same year. The official procedures were worked through in 2012. After all of the approvals and notifications from the authorities had been put on the table back in 2012, it was possible for the ground-breaking ceremony to take place in February 2013.

In a normal year, the three machine units will generate around 52.2 GWh of clean electricity.

ding all of the electromechanical equipment for the entire plant. It was in August 2013 that the team from Schubert led by the responsible project engineer Mario Manseder embarked on the power plant project, which for Schubert was to be the biggest and most complex that had so far been undertaken in the company's long history. "From the generator terminal, the main responsibility for all of the measurement and control technology rested with Schubert. This ranges from establishing a connection with the public mains power grid, installing emergency power generators and a safety power supply across the entire electrical installation, fitting a fire alarm system, the safety lighting right through to the building systems, measurement technology and network technology and incorporating the new process control technology into the existing control room technology at the master control room," explains Mario Manseder. In addition, the team from Schubert was also responsible in the area of the powerhouse for another package of measures and services â&#x20AC;&#x201C; starting with the medium-voltage switchgear with cabling and distribution, the machine transformers and auxiliary power transformers, and the medium-voltage switch cabinets through to the machine control, the process control technology and the associated visualisation. The most demanding challenges included programming the storage tunnel management system. Manseder: "For us the objective was to adapt the control and regulation of the power plant to reflect the fluctuations in the electricity market prices. This enables the operator to generate the maximum return from the production of electricity." In the end, the May 2015

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photo credit: Schubert

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All of the measurement and control technology as well as all the visualisations were delivered by the specialists from the company Schubert Elektroanlagen.

total amount of time spent working by the team from Schubert Elektroanlagen was 23,000 hours. WATER FRAMEWORK DIRECTIVE IMPLEMENTED A significant aspect is controlling the residual water and fish ladder doping, which was configured entirely independently of the operation of the power plant. This is necessary in order to ensure reliable doping in this area even if the power plant is shut down. Ecological considerations and measures generally played an important role: "The residual water specification is stipulated with different levels in different months, but at least 1.2 m3/s must remain in the River Rosanna. This means that the Stanzer Valley power plant is one of the first hydroelectric power plants in Austria to implement the latest specifications of the Water Framework Directive in full." Electricity has been generated at the new Stanzer Valley power plant since the end of October 2014. Following the successful commissioning of machine I, machine II began operating just one month later (in November), and machine III finally followed

in December. In spite of the operation on a trial basis, the operators are delighted that it proved possible to achieve the half-year quantity for winter. It is pointed out that even in its first few weeks and months of operation the power plant generated power strictly in accordance with the fluctuations in the curve of the stock market prices. An essential requirement for this is the storage tunnel, which is generally emptied during the day and then refilled overnight. The storage capacity of the entire tunnel is around 50,000 m3. The machine control is designed in such a way that the tunnel can be run almost completely empty before the machines then automatically run down. A PROJECT FOR 100 YEARS Against the background of tough economic conditions for hydro power in Central Europe, the project in the Tyrolean Oberland region is viewed in an extremely positive light. "The electricity price traded on the exchange has fallen by 40% from the decision to go ahead with construction to the present day. This is critical for the financing, but it must not be forgotten that hydro power is a longterm enterprise. This project is designed for

Technical Data w w w w w w w w w w w w w w w

flow rate: 12 m3/s turbines: 3 vertikal Pelton turbines runner diameter Ø: 1.260 mm buckets width: 425 mm turbine capacity: 13,5 MW generators: 3 synchronous generators generator nominal output: 6.000 kVA cos phi: 0,85 pipe material: steel penstock: length: 500 m vertical shaft: length 100 m tunnel length: 4,8 km trash rack cleaner: horizontal cleaner (Braun) control technology: Schubert Elektroanlagen average energy output: 52 GWh

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w w w w w w w w w w w w w w

100 years. And ultimately I know of no major hydro power project in the past which did not face the situation where the electricity price went up and down," says the project coordinator Jakob Klimmer in summary. The Stanzer Valley power plant became a very special project thanks to the successful participation model. Klimmer says: "If the region and the local communities are involved, there are far fewer problems. Many different forces all pull together – and as a consequence the level of cooperation with the authorities was also exemplary. This was the only way that we were able to implement the project in such a short space of time." In total, the partners in the power plant project have invested 58 million euros in the power plant project. This means that the project management team have managed to deliver the project for around 1 million euros less than the costs which were originally envisaged. There are still a few remaining tasks, landscaping and recultivation works as well as approvals to be carried out over the new few months. The official handover can only be commenced when the full design discharge capacity has been reached.

For further informations: head: 141 m manufacturer: Geppert number of nozzles: 6 number of buckets: 18 nominal rotation speed: 375 rpm manufacturer: ELIN Motoren nominal current: 550 A weight: 50 to pipe distributor: ALPE pipe diemension Ø: DN2000 mm pipe diemension Ø: DN2200 mm tunnel dimension Ø: 3.600 mm steel hydraulics constructions: Braun project development process: INFRA

Schubert Elektroanlagen GmbH Industriestraße 3 3200 Ober-Grafendorf Austria Ing. Christian Schwarzenbohler Head of Small Hydro Power Plant c.schwarzenbohler@elektroanlagen.at Mobil: +43 676-832 53 164 Telefon: +43 2747-2535-164 www.elektroanlagen.at

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Photo credits: zek

On 23 December 2014, the delivery of the stator for the second machine represented the arrival of the final major plant component for the Weinzödl power plant.

WORKS ON WEINZÖDL POWER PLANT COMPLETE FOLLOWING INSTALLATION OF THE SECOND MACHINE Following 30 years of successful operation, the Austrian energy provider VERBUND decided to revitalise the Weinzödl power plant, which began operating in 1982. The two Straflo® machine units, which were showing their age, had to make way for two modern Kaplan bulb turbine generators. The first machine unit was delivered and installed in the spring of 2014. When the stator for the second machine group arrived on 23 December 2014, this was the final major component to reach the power plant in the Graz urban area. Following the final installation and a successful test phase, VERBUND expects that the plant will start operating in mid-March 2015. einzödl in the Austrian state of Styria is located in the northern part of the city of Graz. It has always been a mainstay in the history of hydro power in Graz. Back in the days when hydro power was exploited for mechanical purposes, submerged weirs were used to direct the water from the River Mur near Weinzödl into a channel on the left and right running through the urban area of the capital of the state of Styria. But what was regarded back then as a vital artery for industry in southern Austria became less important over the course of time. The advent of electricity meant that the days of mechanical hydro power were numbe-

red and the channels largely lost their useful function. This was why in 1976 the righthand channel was also completely shut down. However, the 23 km long Mühlkanal on the opposite side of the river was spared this fate – it supplies water to a series of small-scale power plants to the present day. One year later – in 1977 – Steiermärkische Elektrizität AG (STEG) commissioned a study to examine the feasibility of constructing a run-ofriver power plant at the site of the former submerged weirs. Following the positive conclusion of this study and further investigations, the Weinzödl power plant was then implemented from 1979 – 1982.

STRAFLO MACHINE UNITS The power plant on the River Mur, which started operating on 14 June 1982, had two horizontally fitted machine units. They each comprised a twin-regulated Straflo turbine with a runner diameter of 3,700 mm from Andritz, Graz und Escher Wyss AG Zurich with a nominal output of 8,300 kW and a three-phase AC synchronous outer rim generator from the company Elin-Union AG with a nominal output of 9,500 kVA. In the area of the weir of the Mühlkanal, a decision was made to construct a discharge power plant and a third machine unit was therefore installed. Also fitted horizontally, it consists of a May 2015

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A mobile crane was used to transfer the component, weighing around 40 t, for installation. The stator gets into the turbine-generator shaft through a hatch.

After the delicate passage through the hatch, the stator is installed on the moving carriage. For this purpose, it needs to be tilted forwards by 8°.

Precision was required by the installation team from the company Chemserv: just a few cm of clearance allow no room for any mistakes.

single-regulated Straflo turbine with an installed capacity of 200 kW. The fixed doping rate is 11 m3/s. With a power output of 15.5 MW, the Weinzödl run-of-river power plant produced around 63,000 MWh of power per year. CHANGE OF THE TYPE OF TURBINE In 2002, the Weinzödl power plant and three other STEG power plants were incorporated into VERBUND Hydro Power GmbH. Roughly a decade later, the new operator began to modernise the inner workings of the plants. One essential point for planning involved the Straflo turbines which were installed. This is because what was regarded as the very latest state of the art 30 years ago has now been superseded. The basic idea behind the Straflo turbine is based on the concept of the turbine and generator unit. In this type of machine, the runner and generator are located right next to one another and the shaft is only used for storage and not for power transmission. The generator poles are located directly on the outer rim of the runner - outside of the flow-carrying tube. As a result of this innovative but also complicated design, the concept places high demands on the sealing technology because no water must get to the electrical parts of the generator. Straflo turbine generators therefore usually rely on a combination of lip and labyrinth seals. But to make sure the turbine works smoothly, regular maintenance intervals for the machine and in particular the system of seals are mandatory. However, these intervals become ever shorter as the machine grows

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older and as a result of feed water that is particularly rich in sediment. Maintenance costs and outlay increase continuously as a result. The managers in charge were therefore of the view that probably the best way to revitalise and thus achieve the associated increase in output of the overall plant was simply to change the type of turbine. This was a decision which does of course make the whole enterprise considerably more difficult, as project manager Meinhard Wessiak stressed: "Fitting a new type of machine into an existing structure is probably the greatest challenge with this project." The project team therefore decided to replace the two Straflo turbine generators with two Kaplan bulb turbine generators. With an output of 16.4 MW instead of the original 15.5 MW, the bottleneck capacity of Weinzödl power plant is increased by around 1 MW. But the annual output can be increased by 13.5 GWh as a result. This is roughly equivalent to the level of consumption of 4,000 households. STRUCTURAL MEASURES REQUIRED In contrast to the old machines, some of which were situated outside of the flow area, the two new ones are sunk entirely within the flow section. Moreover, the new generators are inclined at an angle of 8° from the horizontal, as a result of the hydraulically substantially greater output. This meant that structural measures were required in order to adapt the two shafts to the new design. In this way, the lip seals, whose maintenance constituted a major pro-

blem and resulted in additional costs, were also eliminated. INSTALLATION WITH A RAIL SYSTEM Following the completion of the construction works, the installation of the new generators was the next major challenge. The biggest difficulty here was handling the generator parts as the dimensions and mass of the new machines are much greater than those of the old Straflo machine units. The first of the two machine units was delivered in the spring of 2014 and fully installed. The installation work was divided up here into several stages. The first stage was the delivery of the Kaplan turbine from the company Litostroj Power. Together with the rotor of the generator, this was installed in the adapted turbine shaft. The generator unit, a brushless synchronous bulb-type generator, was delivered by Koncar Generators and Motors Inc. from Zagreb. The Croatian generator specialists won over the people in charge of the project with their robust, reliable and reasonably priced machines. In line with the wish of the customer, it was designed for the highest possible level of efficiency. In addition, relatively low excess temperatures of the active parts of the generator were agreed - below 65 degrees K. The company Koncar was in fact actually able to undershoot this value by 20 degrees Kelvin this was revealed by a measurement after the first generator had been installed. The production site in the Croatian capital is also only around 190 km from Graz, which with a transport weight of 40 t crucially facilitates the logistics arrangements. When fully instal-

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led, the total mass of a generator is around 92 t. Specifically customised for the Weinzรถdl power plant, the two machines are designed for constant operation with a nominal apparent power of 9500 kVA, with a power factor of 0.9 and a rated voltage of 5300 V. After the turbine and rotor of the generator have been successfully installed, the stator is delivered and assembled. This is lifted down into the newly excavated generator shaft through a hatch. At the bottom of the shaft, the stator is fixed on a moving carriage which is placed on a rail structure. This process is a very delicate undertaking as the shaft and the rail structure, as has already been mentioned, are tilted at an angle of 8 degrees. The high component with its high centre of gravity must therefore be tilted towards the rotor and be fixed in this 8 degree position exactly in the middle. One of the ways this is done is using overhead anchors. The next step is to slide the stator over the rotor very carefully using the moving carriage. This is a task that demands the utmost concentration from the installation team performing the work to ensure that the stator does not tip over with an overhanging centre of gravity. An air gap of just 6 mm illustrates how precisely the workers need to operate here. Finally, the machine is then provided with a cap to make it watertight.

The stator is screwed to the moving carriage and secured with overhead anchors - a delicate moment for the installation team in the turbine-generator shaft. Following successful fixing, the stator can finally be slid over the rotor.

20% INCREASE IN ANNUAL OUTPUT On 23 December 2014, the final critical phase of the project began with the delivery of the stator for the second machine group. If everything goes to plan, the second machine will also be connected up to the grid in midMarch 2015. Thanks to the replacement of the machine units, an additional annual output of 13,500 MWh is expected with the

same volume of water, which would equate to an increase of just over 20%. "This would be roughly equivalent to the annual consumption of a small town," reports VERBUND AG. In addition to generating more power, the long-term benefits are also an extension in the lifespan and the overhaul intervals of the new Kaplan bulb turbines and Koncar generators.

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photo credits: Geppert

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Tyrolean based turbine manufacturer Geppert delivered the electro-mechanical technology for a small scale hydro power plant in the cooling water system of the Enerjisa Bandirma Natural Gas Combined Cycle Power Plant in Turkey.

TYROLEAN HYDROPOWER TURBINE PROVIDES BENEFITS FOR TURKISH GAS POWER STATION As a rule, large-scale combined cycle gas and steam power plants consume immense volumes of cooling water. In many cases consumption is so high that it makes sense to install hydroelectric facilities. This is exactly what was decided for the CCPP Bandirma combined cycle gas and steam power station on the Marmara coast in Turkey. 15 m3/s of seawater are required here to keep the machinery cool. Just a few months ago, exploitation of this hydroelectric potential was made possible by the experienced Austrian hydropower specialists at Geppert as they provided and installed the electro-mechanical technology required. The Kaplan turbine is very well protected from the strongly corrosive effects of salty water and provides a constant power output of 3.5 MW. This job set the experienced Tyrolean turbine manufacturers a number of challenges.

he ceremonial state opening of the new Enerjisa Bandirma Natural Gas Combined Cycle Power Plant – or Bandirma CCPP for short – took place at the end of 2010 and was attended by the Turkish Prime Minister Recep Erdogan. Enerjisa is an immense energy producer and invested around 550 million Euros in the power station that – at full capacity – is capable of generating 916 MW and supplying an annual volume of 7000 GWh to the Turkish grid. In fact, the station is responsible for around 3.5% of Turkey’s total electricity supply and it’s the largest and most powerful power station run on natural gas in the entire country. Its overall efficiency rating of 59% also means it is the most modern and effective facility in Turkey. Bandirma CCPP is situated in the port city of the same name on the

photo credits: EnerjiSA

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SALT WATER INTEGRAL TO THE SYSTEM Seawater from the ocean below is used to cool down the thermic processes in the power station. It is pumped into the facility up a total climb of 30m and having been pumped through the heat exchange system, reaching a maximum temperature of 35°C, it is then fed back photo credits: Geppert

Bandirma CCPP is the largest and most powerful gas power station in Turkey.

southern edge of the Sea of Marmara. The city is home to 130,000 inhabitants and is an important business centre. The port is a particularly important transfer hub between Istanbul and Izmir. The new combined cycle gas and steam power station project was completed with the assistance of numerous established energy businesses, and attracted a large degree of international attention.

The specially designed Kaplan turbine is in permanent use

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into the sea. It made good sense to use the remaining height difference of 26 metres for hydro-energetic exploitation. Obviously, the plant operators wanted to make the most out of this opportunity, so they decided to build a suitable hydropower turbine in the cooling water system. This meant facing a multiplicity of challenges posed by salty water and the local particularities of the site, which is why they called on the experience and products of one of the industry’s best known manufacturers. Not only has Geppert from Hall in Tyrol, Austria, been producing turbines for over 100 years, they have also gathered decades of experience in the management and implementation of international hydropower contracts. In May 2013 the Austrian company was awarded a contract to install the electro-mechanical facilities in Turkey. The system was successfully commissioned at the beginning of last summer. NON-STOP FULL POWER ‘The cooling water is pumped at a constant volume throughout the year. Hence, the combined cycle power plant is in permanent use at full capacity. The plan is to schedule 2 weeks of complete downtime every 2 years for repair and maintenance work’ said Geppert’s project manager, Thomas Marthe (Ing.), expanding on the framework of the agreement. In terms of machine construction this entailed optimising operational performance. Geppert’s designers constructed the Kaplan turbine to take these requirements into consideration. However, this proved less of a problem than the use of salty seawater, which is extremely corrosive for metals in warm conditions of up to 35°C. Marthe continued: ‘It was the first time that we had dealt with a system that actively uses salt water, so we had to spend a considerable amount of time discovering which substances, materials and anti-corrosion coatings best suited the task.’ Ultimately, the main parts of the turbine – the mill wheel, control device, main wheel ring and suction pipe – were all made of a high-grade rustproof Duplex steel alloy. The standard steel housing elements were coated with a very special anticorrosion layer. This helped to ensure the

photo credits: Geppert

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The 6-blade-runner was mounted in last year’s spring

parts would work reliably within the cooling system for many years. HYDROPOWER TURBINE INCREASES ENVIRONMENTAL FRIENDLINESS The turbine was installed to take advantage of a net drop of 25 m and a maximum volume of 15 m3/s, and is usually taken to capacity by the 3.5 MW motor. In addition to the turbine the scope of delivery provided by Geppert also included the generator, the closing flap, a compatible cooling system, and all the electro-technical equipment. This station-withina-station was provided as a turnkey project by a consortium led by Geppert, although a local construction company was responsible for all the building agendas. The Tyrolean company has plenty of experience working on hydropo-

wer projects on foreign soil, so transporting the components did not pose any special challenges. Nevertheless, unpleasant obstacles were encountered. ‘For some inexplicable reason customs procedures were very slow-moving and complicated. This led to a construction schedule delay of around three weeks. Fortunately, we were able to catch up during the assembly and commissioning phase, and managed to stay within the overall completion deadline’ recounted Thomas Marthe. The hydropower station within the cooling water system of the combined cycle steam power plant has now been in non-stop operation since last June, and the power it produces contributes in no small measure to the environmental friendliness of the Turkish high-performance steam power station.

photo credits: Geppert

On the right the new power house for the hydropower plant - and on the left the pump station for the cooling water.

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photo credit: Bosch Rexroth AG

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Münster twin lock: unlimited travel for large motor vessels and push-towing units

WATER-SAVING TWIN LOCK IN MÜNSTER COMPLETED The second chamber of the new twin lock was put into operation in Münster in April 2014. The annual cargo guided through here corresponds to a traffic volume of more than half a million trucks. An electro-hydraulic system solution from Rexroth generates and regulates all of the motion required for the locking processes. The hydraulic cylinders are equipped with the longlasting corrosion protection, Enduroq, and a new generation of the contactless position measurement system, CIMS.

ince the construction of the Dortmund-Ems Canal in 1899, initially one and then a total of three locks as of 1913 and 1926 have been surmounting a height difference of 6.2 meters in the southern section near Münster. Inland water transport has changed considerably in the past decades, however. In the past, shipping traffic was characterized by towboats, but today, large motor vessels and pushtowing units with lengths of up to 189 meters are the standard. This presents new requirements for modern locks and made a new construction of the locks in Münster necessary. HALF OF THE WATER REMAINS IN THE SYSTEM The Münster I and Münster II twin locks exchange 8,000 cubic meters of water per lock process - half of the required quantity per chamber. This provides savings in water consumption. The lock process begins once the flap gates at the upstream head and the miter gates at the downstream head are closed. The water flows via two longitudinal channels on both sides of each chamber and through two transverse channels into the chamber with the lower water level. Through this exchange, both chambers reach the same level in the middle between the respective target marks. While the remaining water is drained downwards in the chamber for the descent, the other chamber is filled up by the water intake structure. A total of ten closures in the channels regulate the water level.

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ELECTRO-HYDRAULIC DRIVE SOLUTION: INTELLIGENT AND RELIABLE Electro-hydraulic drives from Rexroth generate all the motion required for the locking processes, the opening and closing of the flap and miter gates, as well as the eight circulating closures in the longitudinal channels and the two transverse closures. For decades, the company has been equipping locks with drive and control technology all over the world. In addition to numerous constructions in Germany, Rexroth solutions are also being used in the Panama Canal, for example. The hydraulics have a major advantage in that the modular design enables the spatial separation of thrust and drive cylinders. This meant the hydraulic power units for the new Münster I and II locks could be placed below the locks, protected in caverns. Only the cylinders directly at the gates and closures are exposed to splashing. ECOLOGICAL, RAPIDLY BIODEGRADABLE HYDRAULIC FLUID The 16 hydraulic power units each consist of two redundant motorpump groups, with an installed output power of 2x15 kW for the roller gates and miter gates as well as 2x7.5 kW for the flap gates. The A10VSO axial piston pumps used from Rexroth are particularly quiet and achieve a level of efficiency which is well over 90 percent. They are able to generate the required flow by means of the swivel angle adjusting mechanism. A special feature of the Rexroth axial piston pumps is that the service life is independent of the hydraulic fluid. With the environ-

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PROVEN CORROSION PROTECTION IN SALT WATER Cylinders with a stroke of 2,200 mm open and close the 52-ton miter gates with a traction force of up to 450 kN. The cylinder stroke for the 13.2-meter wide flap gates at the upstream head is 8,100 mm. The 10 roller gates for the longitudinal and transverse channels are opened and closed by hydraulic cylinders with a stroke of 3,000 mm. All cylinders have corrosion protection for a long service life. The piston rod coating has the task of protecting the steel substrate from corrosion, thus ensuring its function for decades. More than 30 years ago, Rexroth was the first manufacturer to start supplying piston rods with ceramic coatings in the field of steel construction for hydraulic engineering and for use on the high seas. Since then, the company has been evaluating the operating data of more than ten thousand large cylinders worldwide in the widest range of applications and under the most extreme environmental conditions. A fundamental finding emerged: reliable corrosion protection involves more than the coating of the piston rod. Only the application-specific interaction of coating, tribology, and sealing technology ensures comprehensive, long-term protection. Rexroth provides such coordinated system solutions on the basis of its Enduroq surface technology.

photo credit: Bosch Rexroth AG

mentally friendly, rapidly biodegradable hydraulic fluid based on synthetic ester which is used in Münster, the components used are also able to achieve the same service life as with mineral oil. The electronic components of the hydraulic power units open up many possibilities for diagnosis and permanent condition monitoring. Technicians can call up operating states and change parameters at any time.

Outstanding measure in the expansion program of the southern stretch of the Dortmund-Ems Canal

The high velocity oxygen fuel spraying process, referred to as HVOF technology, is particularly suitable for applications near to water. Nozzles are used to repeatedly apply pulverized alloys to the piston rods at high temperature and speed. In the completely processed state, the layer thickness of the Enduroq coatings is at least 200 µm. The Enduroq coatings have already proven themselves worldwide in numerous maritime and offshore applications. The empirical values in these harsh environments convinced WNA Datteln to also use this corrosion protection on the Münster lock. CHEMICAL AND MECHANICAL TESTS Numerous chemical and mechanical tests are also an integral part of the development of new surface technologies. Thus, in addition to testing scratch and wear resistance, a threepoint bending test is also carried out, whereupon the outer layer must not show any cracks. To demonstrate the long-standing corrosion

resistance, a salt spray corrosion test in accordance with ISO 4536 is carried out with a duration of up to 4,200 h. In addition, Rexroth matches the seals with the coating and the respective application. Rexroth has developed a seal matrix for a wide variety of applications and surface technologies in a comprehensive research project together with the world's leading seal manufacturers. This systematic corrosion protection reduces maintenance and maintenance costs and ensures the long-lasting functionality of the cylinders. HIGHLIGHT OF THE EXPANSION PROGRAM The new construction of the Münster I and II twin locks ranks among the outstanding measures undertaken in the expansion program of the southern stretch of the Dortmund-Ems Canal and ensures that considerably more than the average of 16,000 vessels and push-towing units to date will be handled every year.

Downstream head with miter gate: cylinders with a stroke of 2,200 mm open

photo credit: Bosch Rexroth AG

Locks replace 2,000 trucks daily As constructor, the Federal Waterways and Shipping Administration (WNA Datteln) took over the new construction of a twin lock with two identical lock chambers. The usable dimensions are 190 meters in length and 12.5 meters in width. In order to ensure shipping traffic continued unhindered during the construction work, which began in 1991, the new construction was carried out in stages. The first lock chamber was put into operation already in 2009, and its sister chamber was completed alongside it in April 2014. The annual cargo handled in the twin lock corresponds to a capacity of more than 510,000 trucks. The Münster lock thereby contributes to relieving the road network and reducing CO2 emissions in Germany.

Author: Arnold Habermann / Bosch Rexroth AG Department: Sales Steel Construction for Hydraulic Engineering

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BADEN OPERATORS UPGRADE BY DIVING DOWN

n early 2011 building work commenced on the Aue power plant in Baden in Switzerland. The Limmat river flow power station had started to show its age and the license was due to run out in 2015. Hence, relicensing was a pressing issue, and for the operators – Limmatkraftwerke AG – the task was to compile a suitable package of measures to gain a license for the following 60 years. One issue was adaption to the updated official requirements, and another was the need to modernise parts of the plant that were worn out and outdated. Two years were estimated for the building work on a budget of CHF 20 million.

NEW MACHINE GROUP One of the key terms for relicensing was an increase in the volumes of water discharged to guarantee the minimum water level. In order to compensate possible production losses the decision was made to add a water discharge power plant to the weir with a power output of 0.5 MW. As regards the license for the following 60 years, the power plant had to be thoroughly modernised; in particular the third machine group from 1925. ‘s’Grossi’ or

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During the relicensing process the Aue power plant in Baden (CH) was renovated and a water discharge power station was added.

photo credits: Limmatkraftwerke AG

The Aue power plant in Baden, Switzerland, was officially opened on the 13th September 2014 after three years of intensive building work. Limmatkraftwerke AG invested a total of CHF 25 million in the rebuilding and expansion of their river power plant on the Limmat. The reason for the intensive construction activities was that the license for the power plant was due to run out in 2015, and the associated relicensing procedures had to be followed. In order to comply with licensing standards for the next 60 years, the oldest of the machine groups, dating back to 1925, was replaced completely. Since relicensing entailed guaranteeing a larger volume of diverted discharged water, a water discharge power station was added to the Aue power plant water diversion weir. Two years were planned for the overall building work. However, Baden’s most important groundwater stream flows right under the power plant at Aue and caused considerable difficulties. In order to avoid soiling the stream, the decision was made to dive.

‘Grandma’, as the group was lovingly called, had to make room for a younger and more powerful system. The other two machine groups that date back to 1966 were kept in operation. The machine groups, and indeed the entire power plant, are to be fitted with the latest plant technology. SUBTERRANEAN WATER FLOW COMPLICATED BUILDING WORK When machine group no.3 was installed in 1925 the Francis turbine was a common choice for low pressure requirements. Back then the Kaplan turbine had only been available for 12 years and had not yet become widely established. During relicensing negotiations the decision was made to change the type of turbine in use. Limmatkraftwerke AG chose to replace ‘Grandma’ with a modern 2.28 MW Kaplan tube turbine manufactured by Andritz Hydro producing more than double the power of the old 1 MW Francis turbine. The new machine group is also much larger than the 90-year-old ‘Grandma’, necessitating a wider and deeper space for installation. Work that initially sounded like standard excavation and concreting soon caused a

number of planning problems at the Aue power plant: ‘We are right next to the Aue pump station here, the largest ground water catchment in the region. The big problem in the planning phase was that Baden’s most important ground water flow runs directly below our power plant, so we were forced to be very careful when excavating’, explained Andreas Doessegger, project manager for Limmatkraftwerke AG. Two options were discussed to avoid soiling the ground water. One was draining the excavation site and sealing it using injection technology. The other was for the building work to be carried out by divers. Ultimately, after intensive deliberation, the option with divers was believed to involve the least risk of contamination, greater financial viability and promised speedier completion. DIVING MORE DIFFICULT THAN EXPECTED There are numerous hazards attached to diving and there is limited experience of this specific type of power plant diving work. Furthermore, the hand-sketched plans from 1905 did not provide the divers with information about what to expect. Nevertheless,

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The diving work was divided into 14 stages, alternating between teams of two divers.

The synchronised generator was mounted to the turbine. It has an official power output of 2600 kVA and uses a bevel gear (90°) connected up to the shaft of the turbine.

there were more arguments in favour of underwater building work. This was divided up into 14 construction phases. 2-man teams of were on constant rotation, since each diver is only permitted legally and medically to stay under water for a limited period. At the beginning of each building phase it was necessary to remove material, lift it out and secure the working surfaces. Reinforcements and formwork were put in place. Underwater concreting formed the final part of each stage. In the very first building phase it soon became clear just how difficult the work would be: ‘As soon as one of the divers began to excavate the water misted up, so many of the steps had to be conducted despite poor visibility’, Mr. Doessegger explained. Of course, this had a significant effect on the time needed to complete each step. All in all the divers were busy with excavation work for a full two years.

responsible for the provision, installation and commissioning of the generator and voltage regulator. Premel SA employed two project managers and up to four assembly engineers for three years on these projects. The highly experienced team dealt with the coordination of the various groups and individuals, and execution of the myriad tasks with ease. André Leibundgut, CEO at Premel SA, was very pleased having overseen the successful commissioning of three generators and emphasised the importance of this project for the company: ‘The installation of these generators shows that Premel is very present on the northern side of Switzerlard and is capable of completing large contracts. The reaction time of our employees in Dübendorf is very good showing how close to customers we

are’. In September 2014 the commissioning of machine group no.3 marked the successful completion of the ‘Kraftwerk Aue’ relicensing process. On the 12th September 2014 Limmatkraftwerke AG held its project completion ceremony in Baden and expressed its gratitude to all the companies and individuals involved in the successful period of cooperation. The new machine group will enable Limmatkraftwerke AG to increase the annual production at the Aue power plant by 2.5 GWh, the rough equivalent of 570 Swiss households. The water discharge power plant produces a further 3 GWh per year – the equivalent of around 670 households. In total it is calculated that an overall investment of CHF 25 million will be able to increase annual power output by 5.5 GWh.

NEW TURBINE – MORE POWER Once building work was completed the entire excavation was drained. ‘The cavity was drained just before the turbine was delivered in October 2013, so we were very relieved when everything proved to be watertight, said Doessegger. The new turbine is a bevel wheel Kaplan tube turbine manufactured by Andritz Hydro. The wheels have a diameter of 2600 mm and rotate at 146 rpm. The max. amount of water to flow through the turbine is 45 m3/s, flowing down a net drop of 5.6 m. The new max. power output is 2.28 MW. A synchronised generator has been mounted to the turbine and produces 2600 kVA via a bevel wheel gear (90°) hooked up to the turbine shaft. The heat generated is removed via a cooling system and the water fed back into the Limmat. Premel SA from Tessin was May 2015

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photo credits: Pedro Filipe

Bogotá is the capital city of Colombia and it is the largest urban municipal catchment area in Colombia. Also it is one of the fastest growing cities in South America.

TWO POWER STATIONS IN BOGOTÁ’S DRINKING WATER SYSTEM REPLACE PRESSURE REDUCTION VALVES Bogotá is the capital city of Colombia and draws its drinking water from a number of dams in the surrounding mountains. In total, three supply networks transport the water to storage tanks in Suba and Usaquen via drinking water treatment plants. Previously, to relieve the immense pressure within the water pipelines, the water had to pass through pressure-reducing valves. In 2011, Acueducto de Bogota S.A., the municipal utilities company in charge, decided to exploit this previously wasted energy and ordered the construction of two drinking water power stations. The Colombian consortium contracted with the job imported Austrian hydropower know-how.

MOUNTAINS AS SUPPLIERS OF DRINKING WATER Suba and Usaquen are the names given to the two drinking water storage tanks in

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Suba is one of two drinking water storage tanks in Bogotá. In order to relieve water pressure in the pipelines, the operator used pressure reduction valves. Now a turbine uses this former wasted energy.

photo credits: Gugler

pproximately 8 million people live in the metropolitan region of Bogotá at 2600m above sea level. It is the largest urban municipal catchment area in Colombia and one of the fastest growing cities in South America. The main part of Bogotá consists of the main district, Distrito Capital or D.C. for short, which is subject to the rule of central government and its special status is comparable with that of Washington D.C. in the USA. The most important infrastructural challenge posed by a city growing at such a rate is the provision of sufficient drinking water and energy, while exploiting the existing resources as universally and efficiently as possible. The two drinking water power stations, ‘Suba’ and ‘Usaquen’, represent the move to use natural resources efficiently.

Bogotá. They are supplied by a number of dams up in the mountains surrounding the city and suburbs. The water is transported from three supply networks - Chingaza, Tibitoc and La Regadera - to several drinking water treatment plants in the city, where the water is stored in the tanks ready to be fed to homes and offices across the area. WATER PRESSURE RELEASED THROUGH SPECIAL VALVES Until now, in order to relieve the water pressure in the pipelines, it was released using special valves. However, this energy was wasted forever. The operators of the drinking water system, Acueducto de Bogota S.A., decided to find a way of utilising the energy and contracted a consortium with the construction of two drinking water power stations. Instead of disappearing through the pressure reduction valves, the pressure is now transformed into electricity and fed into the 34.5 kV public grid.

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At the Suba plant a new power house had to be built because of a lack of space.

Suba Power Plant Turbine: w Type: Horizontal Francis w Manufacturer: Gugler w Flow Rate: 5.65 m3/s w Gross Head: 52.5 m w Capacity: 2645 kW

photo credits: Gugler

Generator: w Type: Synchron w Manufacturer: Indar w Capacity: 2850 kVA w Rotation Speed: 514rpm w Frequenzy: 60 Hz

HYDROPOWER ‘MADE IN AUSTRIA’ The consortium – ‘Consorcio Generacion Bogotá’ – consisted of four Colombian companies and was the general contractor for all construction tasks, also taking responsibility for the delivery of the entire range of electromechanical machinery (including transformers and 34.5kV a medium voltage plant), assembly, installation and commissioning, plus two years of operational management and maintenance for the two hydroelectric power plants. The consortium chose to equip the power plants with the benefit of expertise provided by Gugler Water Turbines GmbH. This long-standing Austrian company provided two Francis turbines, the accompanying synchronised generators, shut-off doors, bypass systems with hydraulic motors, LV and MV

switchboard controls, transformers and +SCADA controls. Gugler was responsible for supervising installation and commissioning at both power plants. HORIZONTAL FRANCIS TURBINES A horizontal Francis turbine was installed in each of the two power plants. In order not to put the quality of the drinking water at risk, both of the Francis wheels were milled using forged, non-rusting material (CrNi 13 4). Additional anti-corrosion coating ensured compliance with all the statutory hygiene regulations. The power station known as Usaquen offers a net head of 71.5m at a flow rate of 2.85 m3/s. It can provide a power output of 1810 kW. The turbine and the generator were built into the existing pumping station.

A horizontal Francis turbine was installed in each of the two power plants. The power station known as Usaquen offers a net head of 71.5 m at a flow rate of 2.85 m3/s.

Water at the Suba power station only achieves a net drop of 52.5m but it can flow through the turbine at 5.65 m3/s; so the output generated here comes to 2645 kW. At the Suba plant a new power house had to be built because of a lack of space. INTERNATIONAL FLAGSHIP PROJECT In August 2013 the two power stations situated 2600m above sea level were successfully commissioned. The flagship project in Colombia highlights the opportunities and potential of hydropower, and how resources can be used in multiple and efficient ways. The hydropower know-how provided by Gugler Water Turbines GmbH underlined the high international standing enjoyed by Austrian specialists, adding another chapter to the country’s global successes in this field.

Usaquen Power Plant

photo credits: Gugler

Turbine: w Type: Horizontal Francis w Manufacturer: Gugler w Flow Rate: 2.85 m3/s w Gross Head: 71.5 m w Capacity: 1810 kW Generator: w Type: Synchron w Manufacturer: Indar w Capacity: 2000 kVA w Rotation Speed: 720 rpm w Frequenzy: 60 Hz

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Utilising drinking water to generate energy is an increasing trend. More and more communities in the Alps want to utilise the potential energy that resides in the sources situated at high altitude by having a drinking water power plant. The plans usually become concrete when a pipeline system which has already become outdated is due to be replaced. In the past year, two Austrian communities demonstrated the ideal way to implement such a project. The key aspect in both cases was the choice of optimum pipe material. Both of the developers opted for ductile iron pipes from the traditional Tyrolean manufacturer TRM, which display their benefits in full particularly when they are used for drinking water power plants.

photo credit: Alpecon Kulturtechnik

DUCTILE IRON PIPES - BACKBONE OF MODERN DRINKING WATER POWER PLANTS

ven in the Alps, with their plentiful supply of water, the number of streams on which it is today possible to construct new smallscale hydroelectric power plants has become clear and easy to understand. In contrast to this, the potential for drinking water power plants is far from being exhausted. In particular those communities that are blessed with lots of water and obtain their drinking water in part from great heights find that in some cases they have the optimum conditions for this. The two communities of Stainach-Pürgg in Styria and the community of Bach in Tyrol's Lech Valley recently showed how this potential can be exploited.

photo credit: e2 / Semmler

OLD PIPELINE REQUIRING ACTION For Stainach-Pürgg, the original springs are extremely important. They safeguard the main thrust of the supply of drinking water to the community. The karst spring was established and the source feed line constructed back in the 1960s. At the time, an Eternit pipeline was laid underground, but in the last few years its condition clearly left something to be desired. The old pipeline with a DN125/150 diameter repeatedly sprung leaks in recent years, leading to fractures of the pipe. The worst of the damage was repaired using PE pipes. There was therefore a need to take action. Four pressure breaker shafts were installed between the highest point of the pipeline and the high-level reservoir from which the drinking water

The new DN200 penstock for the Stainach-Pürgg power plant was laid over a distance of 1,020 m through terrain which in places was extremely difficult to access. In addition to the new TRM ductile iron pipeline, the remains of the old Eternit pipeline dating from the 1960s can still be seen.

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The TRM ductile iron pipes for the Bach drinking water power plant were laid over a distance of 2.2 km.

enters the distribution pipeline. One study that was prepared in advance ultimately concluded that the most economical solution was to use a section of pipeline which should enable a drop height of almost 300 m. So enough of a drop to make it possible to operate a power plant efficiently with a feed rate of up to 30 l/s. "What gave me a bit of a headache right from the outset was the question of how a high-pressure pipeline can be laid in this steep terrain. In the upper section in particular, it is so steep that when we carried out inspections we found ourselves climbing more than walking along the planned route of the pipeline. In addition, the terrain is more or less undeveloped. There was only one single possibility for accessing the marked-out route. Ultimately, three pipe depots were created from where the pipes were then transported to their respective installation site using a digger," recounts Manfred Semmler, the project manager from e2, the planning office that was commissioned to carry out the work. CAST-IRON PIPE IS THE IDEAL MEDIUM On the other hand, the question of which pipe material should be used for the 1,020 m long section of pipe was very quickly answered. Semmler says: "It was clear to us that, with the pressure conditions that exist, ductile iron from TRM was the only possible choice. We decided to opt for the restrained VRS®-T connections as the entire pipeline was to be run over the steep terrain with a DN200 diameter in a spiral form – and we were therefore not supposed to require any fixed points set in concrete." He also points out that, in extremely inaccessible terrain,

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photo credit: e2 / Semmler

The new penstock is adapted to the shape of the terrain. To ensure that no fixed points set in concrete needed to be produced, the entire pipeline was given a restrained design.

there would scarcely have been any possible way of delivering bedding material. This was yet another reason why the people in charge made the decision to use TRM cast-iron pipes. Ultimately, bedding material is not absolutely essential when laying the cast-iron pipes. Another important quality advantage for the pipe material which is used is its pipe inside coating made from cement mortar. The primary purpose of this is to protect the pipe from the corrosive properties of the water, but it also helps to ensure the pipe has absolutely no leaks at all. Particularly with pipes that carry drinking water, it is absolutely imperative that no foreign materials whatsoever are able to get into the pipeline. In addition, the planner also cites the extreme stability and durability of the ductile iron pipes from TRM. "In this project, we tried to install high-quality components wherever possible. Ultimately, this is a project which should also help to benefit the next generation," says the project manager.

LAYING OF PIPELINE UNDER ADVERSE CONDITIONS Nevertheless, the omens for the work to lay the pipeline were not good. The persistent rain last summer had saturated the ground, and some hillsides were even threatening to slip down. In view of these adverse conditions and the difficult topography of the terrain, it was simply astounding that just two men from the construction company commissioned to carry out the work were able to construct the entire pipeline in just eight weeks. All of the works were carried out using just a conventional 27 tonne chain excavator. In the end, the new pipeline was laid underground in the route of the old pipeline with a coverage of 1.0 to 1.40 m above it. PROFITABILITY OVER THE LONG TERM When the construction works began to draw to a close in the autumn, it was time for the electrical machinery equipment to be installed. A 1-nozzle Pelton turbine which is designed for a bottleneck capacity of 75 kW was

used. All water-carrying parts are of course designed to be fully suitable for use with drinking water. The new drinking water power plant was switched on for the first time in November of last year. And this was successful; the small-scale power plant has been running continuously without any interruption since the autumn of last year. The grand opening ceremony followed at the end of November. "The continuous feed rate from the original sources does of course very much benefit the plant. This has so far never fallen below 27 l/s. This means that the operators can generally expect to achieve an annual working output of 600,000 kWh," says Semmler. For the community in the Enns Valley, the investment of around 620,000 euros is definitely not chikken feed. But with the guaranteed feed-in tariff of 10.55 cents/kWh for 13 years, the project will pay dividends over the long term. The people in Stainach-P端rgg are convinced of this. Moreover, today there is no longer any need to worry that precious drinking water will be lost on its way down the valley. In its new pipeline, it is safe and secure. MILESTONE FOR TYROLEAN COMMUNITY The situation was not dissimilar for the small community of Bach in Tyrol's Lech Valley. However, initial plans for a dedicated drinking water power plant were on the table there back in the 1990s. Although at the time they were deemed to be uneconomical, judicious planning and a collective will to cooperate then helped the project to make the breakthrough. The central element of the construction project was the costly construction of a forest road which allows people to gain access to the route of the existing pipeline for the first time. Pipe laying in steep terrain with the walking excavator.

photo credit: Swietelsky / Scharler

TRM ductile iron pipes of the PUR Longlife DN200 type replace the old pipeline, which in some places is made of steel pipes and in other places is made of asbestos pipes.

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The most important source of drinking water in this community, which is situated at an altitude of more than 1,000 m, is considered to be the forest spring. It is established at 1620 m above sea level, its feed rate is around 30 l/s, with the annual average hovering around 28 l/s. The community has been getting the majority of its drinking water from this source for around 70 years. An entire forest was cleared for the construction of the well chamber and pipeline in the 1940s. Whereas the natural landscape of this area has slowly recovered, the technical condition of the pipeline has steadily gone downhill. "The old pipeline was no longer state-of-the-art – and was also in need of remediation. It was made on the one hand from old steel pipes and on the other hand from asbestos pipes and in some places it had been repeatedly 'patched'," explains mayor Egon Brandhofer. The rock cutter was deployed over a distance of 1.2 km.

PIPES GUARANTEE RELIABILITY There was no doubt among the people in charge of the project about which pipe material should now be used for the new pipeline: Only DN200 cast-iron pipes from the company TRM were considered. First of all the criterion of operational reliability was the primary concern, as the mayor emphasised, but the issue of durability also played a major role. It was a stated aim of the community in the Lech Valley to lay a pipeline which would be in service over many decades – and would not have any failures, fractures or leaks.

Technical Data Drinking Water Power Plant Stainach-Pürgg w w w w w w

photo credit: Swietelsky / Scharler

Flow Rate: 30 l/s Head: 299,70 m Output: 75 kW Penstock: length: 1.020 m Ø: DN200 Material: ductile iron Manufacturer: TRM Average Energy Capacity: 593 000 kWh

The perspective from the opposite slope reveals how inaccessible the area for the route of the pipe is.

photo credit: Alpecon Kulturtechnik

FOREST ROAD AS THE KEY TO SUCCESS It was time for the old pipeline to be replaced. For the people from the community who were responsible for this, this was an appropriate opportunity to pick up an old idea again: the construction of a drinking water power plant. The more intensively planners and the local community consequently looked at the project, the more obvious it became that the whole enterprise would only be possible if sufficient access to the area of the construction site could be ensured. The basic requirement was therefore for a forest road to be constructed. The construction of the 1.5 km long forest road subsequently proved to be very demanding. Rocks, steep terrain crossings and the inaccessibility of the area presented a number of challenges for the construction company. In general, the new pipeline route did not envisage any major deviations from the existing route. But what was important here was to ensure that a sufficient gap from the old pipeline was maintained. After all, operation of this pipeline had to be maintained in the meantime. The old pipeline could only be removed once the new one was up and running. The route of the new pipeline extends over a total length of 2.2 kilometres.

In addition, with drinking water pipelines especially there is also always the issue of hygiene criteria. In this regard in particular, the TRM pipes made from cast iron with the cement mortar lining comprising blast furnace cement or Portland cement offer a particularly high level of safety. In addition, this inner lining guarantees a completely neutral taste - a key prerequisite for contact with drinking water. PIPE TRENCH IS CUT OUT The laying of the high-pressure pipeline in difficult terrain began on 2 June last year. The most important tool for the construction team very quickly became the rock milling machine, which excavated a 40 cm wide pipe trench from the rocky ground beneath. Of the route of the pipeline over a distance of 2.2 km, around 1.2 km needed to be cut using photo credit: Alpecon Kulturtechnik

photo credit: Swietelsky / Scharler

The ductile iron pipes used ensure that pipes can also be laid in pipe trenches with lots of bends in them.

Drinking Water Power Plant Bach w w w w w w w

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Flow Rate: 30 l/s Head: 420 m Output: 155 kW Penstock: length: 2.200 m Ø DN200 Material: ductile iron Manufacturer: TRM Average Energy Capacity: 700 000 kWh

Both the pipeline and the cable tube were wrapped in a fleece lining to protect them.

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photo credit: Swietelsky / Scharler

Laying a pipe on a steep slope requires even the most experienced excavator drivers to test themselves to their limits.

the milling machine. In the steeper section, blasting operations were also unavoidable. The cutting operations delivered a not inconsiderable benefit in particular for the ballast bedding for the pipes: The excavated material which was prepared with a particle size of 0.22 mm was ideally suited to bedding down the pipes in a narrow pipe trench. In order to protect them from any possible mechanical defects, they were wrapped in a fleece lining. ANCHORING ON THE ROCK IN THE STEEPEST SECTION While cast-iron pipes from the pressure class K9 with pressure resistance of PN40 were fitted in the top section, pipes from class K11 /

PN63 were used in the section at the bottom, some parts of which are very steep. The very last section of the pipeline runs over an almost vertical wall of rock with a gradient of 70째 to 75째 - this was the most challenging part for the team laying the pipeline: In this area shortly before the machine house it was no longer possible to lay the pipeline underground. It was secured with rock anchors and clamps on the fittings facing the slope. This meant that each pipe was securely fixed and anchored to the rock. The topography of the terrain resulted in one high point for venting and one low point for draining the pipeline. The complicated pipe-laying work was completed at the end of August. REVENUES BENEFIT COMMUNITY The new power house is situated around 70 metres below the high-level reservoir. From there, the water that has passed through the turbine is pumped back up to the high-level reservoir, depending on the particular requirements. The machine house now contains a drinking water turbine that rotates with a design output of 155 kW. It ensures that an average of around 700,000 kWh of power is generated each year. "The revenue from the drinking water power plant is intended to benefit the community directly; we want to use it to fund the construction of the new community hall building," says mayor Brandhofer. Both the community of Bach and the community of Stainach-P체rgg have gone to considerable time and effort to exploit the hydro power potential of their drinking water. And they have done this with great success. In both cases, it has proved possible to deliver modern ecofriendly power plants which are integrated perfectly into the infrastructure for the relevant supply of drinking water. A primary prerequisite for the success of these projects was the construction of a high-quality and extremely durable high-pressure pipeline made from ductile iron pipes from TRM. Ultimately, both projects have been constructed for the benefit of future generations.

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photo credits: Austrian federal forestry agency

Completed after seven months of construction: the penstock for hydropower plant Forstaubach Gleiming. The facility is operated by the Österreichische Bundesforste (Austrian federal forestry agency).

PIPELINE SUCCESSFULLY LAID FOR THE FORSTAUBACH GLEIMING POWER STATION teep terrain, difficult soil, poor weather and a stream crossing: these were the greatest challenges to the laying of the penstock for the Forstaubach Gleiming power station. Given such conditions it is also not surprising that the 3.2 km long penstock could be completed only just before the end of the year after a construction time of 7 months. There’s nothing you can do against bad weather, but it was possible to counter the difficult geological conditions in one section of the line using appropriately robust material. The soil investigations conducted before the start of construction had shown that earth

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movements could not be ruled out in the middle part of the line. This is why ductile cast iron pipes from Tiroler Röhrenwerke TRM were used for this section whilst GRP pipes from the German manufacturer Amiantit were used for the upper and lower part of the power station line. EVERYTHING FROM A SINGLE SUPPLIER The pipes for the “hybrid line“ were provided by the Lower Austrian pipe specialists Etertec GmbH & Co KG. The distribution company based in Brunn am Gebirge convinced the operators during the tender procedure through its excellent price-performance ratio

photo credits: Etertec

Back in the middle of May last year construction work was commenced on a new hydroelectric power station of the Austrian federal forestery agency (Österreichische Bundesforste) in the Styrian-Salzburg border area. Forstaubach Gleiming GmbH’s plant, which is equipped with a dual machine combination, will be put into service this spring. However, before this the tricky job of laying the pressure pipes had to be completed.

All pipework and special fitings for the power plant pipeline were supplied by Etertec GmbH & Co. KG.

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photo credits: Etertec

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1 LINE – 3 SECTIONS From the inlet structure built as sluice gate, the first section of the penstock was laid along a length of 738 m in the form of Flowtite GF-UP pipes with a diameter of DN1400 and pressure rating of PN 6. In the middle section of the line, cast iron pipes resistant to tensile and shearing force were used over a total length of 1,217 m due to the uncertain soil properties. A transition was created for the different pipe materials using a special moulding and the diameter of the penstock simultaneously tapered to DN1000. Leading to the power house, the final section of the pressure line of 1,203 m Photo credits: Etertec

“Hybrid pipe“: The 3.2 km penstock is made from cast iron and GRP.

and outstanding references for comparable projects. In addition to the cast iron and GRP pipes, Etertec also provided all special parts such as couplings, reductions, discharge outlets and specially made ventilation control valves.

in length was then executed as a GRP line with a diameter of DN1200 and pressure fittings of PN 10 and 16. In view of the persistently wet weather whilst the pipeline was being laid, the soil along the pipeline could not completely dry out at any time. Combined with an extremely steep terrain in part, these were by no means favourable conditions. Nevertheless, Pitzer, the Schlaming-based company entrusted with the laying of the pipes, did a great job. Another challenge was to cross a stream with the pipeline which proved to be an involved undertaking due to the water conservation measures. Commenting on the complexity of the work, graduate engineer Gerhard Breitenbaumer from Austrian federal forestery agency, explains that the situation was compounded due to the fact that traffic had to be controlled in the lower area of the pipeline because it ran along a public road. POWER STATION SOON TO GO INTO SERVICE A combination of two machine sets is used in the machine house of the Forstaubach Gleiming power station. A vertical-axis Pelton turbine and a Francis turbine will be in operation – both from EFG. The decision in favour of a double turbine solution was made due to the special hydrological conditions in Forstaubach. With a net head of some 94 m and a flow rate of 2.100 l/s, the machine sets together will generate a total output of 1.7 MW and therefore around 6.5 million KWh per year of clean energy. The pilot operation is planned for the end of April.

Technical Data • Penstock: ductile cast iron/GRP • Net head: 94 m • Pressure levels: PN 6 – PN 16 • Ductile cast iron pipe: DN1000 • Manufacturer: TRM • Length: 1.217 m • Flowtite GRP pipes GF UP: DN1400/1200 • Manufacturer: Amiantit • Length: 1.941 m

The steep terrain and humid weather posed a special challenge to the technicians during the installation phase.

CONTACT: u.steidle@etertec.at

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1 photo credit: Bilfinger VAM

Bilfinger VAM Anlagentechnik has been working on the refurbishment of the steel double penstock system of the French 332-MW Malgovert power plant since 2013.

REFURBISHMENT OF THE EDF MALGOVERT HYDROPOWER PLANT PENSTOCK The French 332-MW Malgovert power plant was put into operation in 1953. 65 years later, in 2012, Bilfinger VAM was commissioned to refurbish the penstock system consisting of two parallel, above-ground steel penstocks with a diameter of 2.2 m. The operating pressure ranges from 10 to 85 bar. The refurbishment contract comprises the replacement of 15 percent of the entire penstock, including elbow pipes, joints, armatures and saddle clamps, among other components. The company had to replace all existing saddle clamps of the lower half of the penstock with new side- and height-adjustable clamps. The installation works started in 2013 and are to be completed in 2015. [by Ronald Hödl, Bilfinger, VAM, based on his presentation at Viennahydro Conference 2014]

fter 67 years in operation, the Malgovert power plant, located in the Rhône-Alpes region, is still one of the top-performing power plants in Southern France. It is operated by EDF (Électricité de France SA), the second-largest electricity producer in the world. The process water comes from the Tignes Dam, from where it passes a 20-km-long process water gallery before it reaches the service chamber. The starting point of the retrofit project is the service chamber, which is set at 1,492 m above sea level. The total length of the penstock lines is 1,459 m, they are supported by a total of 17 massive concrete foundations. Between these foundations, at intervals of about 8 to 9 m, additional concrete saddle clamps are set up. Upstream, right before the power house, the penstocks split first into 4 and finally into 8

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pipe sections leading the process water to the 8 installed Pelton turbines. The operating pressure in the service chamber is approximately 7 bar, at the power house it amounts to about 85 bar. PENSTOCKS ON AN UNSTEADY SLOPE The penstock is situated in a geologically unsteady territory, especially the lower penstock section from about midway downstream. As has been documented for decades, the concrete foundations move by about 4 cm a year. The specific movements have been well documented and are known for each section of the penstock. To compensate these movements length-adjustable joints were placed. They were adjusted during the annual maintenance works, as is the usual procedure. When the joint reached the end of its adjus-

table length the penstock was cut and the joint was repositioned. Welding in a new steel ring filled the resulting gap. Image 3 shows how the adjustment was executed. Each of these circular welding seams is a sign of the repositioning of the joint. Of course the movement of the slope also affected the existing pipe saddles. Over the years the concrete saddles shifted from their original position, in most cases they sank into the ground. The existing penstock had not been designed with height-adjustable elements and for this reason simple measures had been taken over the years, such as putting simple supporters underneath the penstock (see image 4). Summarized, the status of the penstock before refurbishment reveals that the limited compensation of the length of the penstock resul-

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Schematic illustration of the penstock: the double-lined penstock runs across a total length of 1,459 m. It is laid above ground and supported by 17 foundations and further concrete supporters placed at intervals of 8 to 9 m. Before the penstock enters the power house it is divided in two succeeding branchings.

ted in the installation of additional steel rings. The alignment of the penstock close to the power house was out of line. Some rings were installed with insufficient fillet welds. The concrete foundations required new support. The gap between several pipe saddles and the penstock amounted to up to 40 cm (Image 4) and was closed with provisional supporters. In the bicurcations of the penstock, the flange connections ∅ DN2100 to ∅ DN1400 were welded on the inside, as were the connections of the bifurcation from ∅ DN1400 to ∅ DN1000. AN ENCOUNTER WITH TECHNOLOGY FROM THE 1950S The original penstock was manufactured in a way typical of the early 1950s. Between the massive concrete foundations the thin-walled penstocks were supported by steel wire ropes or high-strength steel rings (Image 6). At the concrete foundations conventional pipes were used. The bifurcations were made of thick-walled cast steel. Baffle plates were placed on the inside to reduce flow loss. The planning for the refurbishment of the penstocks started back in 2007. Five years later Bilfinger VAM Anlagentechnik was commissioned with the mechanical part of the project. The contract comprised the manufacture and installation of the affected section of the penstock, of the connections, the steel construction components and the supervision equipment. The entire project is executed by a consortium consisting of Bilfinger VAM Anlagentechnik and project leader Spie Batignolles TPCI. The latter company is responsible for all necessary construction measures, the construction site and the infrastructure of the site.

photo credits: Bilfinger VAM

The original penstock showed a considerable gap to the existing pipe saddles.

To compensate for the slope movement occurring by the years, new steel rings were installed whenever the joint range was exhausted.

photo credit: Bilfinger VAM

graphics: Bilfinger VAM

REFURBISHMENTS AND NEW INSTALLATIONS The contract for the plant engineer experts in detail included providing new components, which were to replace original elements, as well as refurbishing old construction parts. Newly manufactured and installed components comprised all of the 12 length adjustable joints in the affected section – including manholes, all interface pipes (connecting the old thin-walled, rope-supported pipe and the old thick-walled pipe), the branch pipes of the bifurcations 1400/1000, the bifurcations, the majority of adjustable pipe saddles as well as the drainage system. A smaller part of the contract were refurbishing works. Flange connections of the bifurcations, corrosion protection of existing construction elements, the armatures of the drainage system and even the frames of the bifurcations 1400/1000 were refurbished. During the replacement works and the installation of new elements, and eventually during the pressure tests, some defects of the components were ascertained. For this reason some construction elements had to be redesigned and were integrated into the concept, such as the replacement of steel wire ropes with steel bands on the connecting pipes. Furthermore all 4 bifurcations 1400/1000 were replaced with new ones, as they had been welded on the inside at the underwater section of the flange connection. OLD AND NEW REQUIREMENTS The engineers of Bilfinger VAM Anlagentechnik faced huge challenges with some important intersections of old and new components. The first step was to define a harmonised basis for requirements of the manufactured parts from the old days and those of today. It turned out that the definition of these standards was more difficult than their cal-

A penstock section with the new pipe saddles already installed. The image shows the wire rope support on the existing penstock.

The pipe with a new length-adjustable joint.

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photo credits: Bilfinger VAM

The flange connection on one of the bifurcations 2100/1400 has been repaired. The original consist of thick-walled cast steel. They have been optimized against flow loss through baffle plates on the inside.

REAL MODEL FOR TEST PURPOSES Previous to the detail engineering works various parameters had to be defined. The axis of the new penstock had to be partly re-established as it had shifted in some sections due to slope movements. The most important documents for these calculations were recent measurements from 2012. Since the operating

photo credits: Bilfinger VAM

So far more than two thirds of the welding works have been completed. The inspection showed a welding defect rate of less than 0.55 percent.

system was to be replaced by an “open system” the effects of any possible tilting angle of the joints of up to 1 degree had to be defined. Early on in the project a functional model was built to receive well-founded data. The essential details were realized 1:1 to subject the seals for the structure element to realistic conditions and thus collect the most authentic data. Furthermore various parameters and specifications had to be considered regarding the supports: first inspections made it clear that the existing penstock structure was in no way designed to withstand extraordinary forces, such as earthquakes. Due to a lack of reinforcement elements in the civil structure the load transfer is rather limited. To compensate for the geological movements it is necessary for the supports to be adjustable vertically, laterally and axially. The aim is to embed the penstock in a saddle design, which allows for operation in any kind of loading conditions. At the connecting pipes several steel wire

THE CHALLENGE OF THE INSTALLATION A minor, yet essential part of the project's success was the eagerness of Bilfinger VAM Anlagentechnik's team to adapt to the French culture, local customs, etc. Some of Bilfinger's workers quickly managed to communicate on the construction site with their French colleagues in their language. The first task was to dismantle the existing pipes. The team had to work under time pressure, since the deadlines were given. Projects

New bifurcation 1400/1000 with a blockable joint.

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MATERIAL AND WELDING QUALITY The material used consisted mainly of steel, meeting EN ISO standards and specific project-related standards. High-performance steel was used for the new penstock. The main reason for its use was a possible weight reduction and the limited crane capacity on the site due to the local conditions. The high number of welding works was carried out in accordance with the highest possible standards. The high quality was confirmed by the results of the subsequent quality inspection applying the common EN and EN ISO standards. 85 percent of the welding works had been completed in July 2014 and showed a welding defect rate of less than 0.55 percent, that is 15 m of defective welding seam per 2,745 m. 100 percent of the welding seams on the penstock were checked by VAM's own quality controllers (Image 8), employing state-of-the-art equipment for non-destructive testing. A novelty on the site was the application of an automated ultrasonic weld inspection. More than 100 welding seams were generated adding up to a total length of 750 m.

photo credits: Bilfinger VAM

culation. The definition concerned the safety concept, the standards, the inclusion of loading cases – such as earthquakes, and general system calculations. The latter was relevant since the penstock system is now to be operated as an “open system”, meaning the length is to be compensated through open and flexible connections (joints), to name only one of the comprehensive calculations made. 150 drafts were submitted to and accepted by the client company by July 2014, revisions not included. Since the power plant has been built in the 1950s not all technical documentation was available.

ropes had to be removed to perform the weldings. As a consequence the ropes were replaced with clamping elements (steel bands). The bifurcations were designed to withstand an operating pressure of 85 bar – and a test operating pressure of about 129 bar (Image 9).

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photo credits: Bilfinger VAM

New interface pipe with integrated manhole.

Helicopter operations were required for the transport of materials due to the difficult accessibility of the construction site.

like this can sometimes feel like a race against time. Furthermore the installation works began in the winter time and the team had to perform their job in snow, wind and freezing temperatures. An important aspect was the safety on site: Bilfinger VAM Anlagentechnik has a record of extremely few workplace accidents. Before the construction works began exact standards concerning safety on site had been elaborated together with the client and the safety coordinator. Again Bilfinger's standards proved successful. FLEXIBILITY AND BEST SKILLS On average about 65 Bilfinger VAM Anlagentechnik workers are on site, working night and day shifts. If more staff is needed the company's workforce can quickly and easily be supplemented. It is important for the team to have special machines and vehicles available at all times. The rather difficult accessibility of the construction site required the

The refurbishment works are to be successfully completed this year.

use of walking excavators, snowmobiles and other specific equipment. The company has a large assortment of gadgets and machines. In certain sections of the site even helicopter operations were necessary. The Bilfinger VAM Anlagentechnik team was able to demonstrate its great flexibility in more than one situation, for example when the team discovered defective parts on the penstock and together with EDF had to come up with a quick technical solution to remain on schedule. This situation revealed the perfect in-house collaboration between the departments for design, structural analysis and manufacturing as well as the installation team on site. The refurbishment project is not yet finished, but will undoubtedly be completed successfully. Bilfinger VAM Anlagentechnik not only offered its renowned extensive knowhow but was a reliable partner to the client in meeting the economic conditions to realize this complex project within its given limits. [by mechanical engineers Ronald Hรถdl and Clemens Keplinger]

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BRAUN'S TRASH RACK CLEANERS PERFORM WELL AROUND THE WORLD Bhutan, Costa Rica, Germany, Albania, Italy, South Africa – these are just a few countries where plant operators rely on the technical know-how of Austrian Braun Maschinenfabrik GmbH and the top-quality performance of the company's trash rack cleaners. The product range of the hydraulic steel engineering experts covers trash rack cleaning machines in a variety of designs. From large-scale to small-scale power plants, Braun has the solution to all requirements and application needs. raun Maschinenfabrik, based in Vöcklabruck, Upper Austria, has been engaged successfully in the fields of hydraulic steel engineering and the construction of trash rack cleaning machines for over 50 years. In a business area that is constantly growing, Braun offers individual solutions to power plants of all sizes with a comprehensive product range. Braun's portfolio covers conventional cable winches, hydraulic telescopic arm trash rack cleaners, fully automatic cleaning machines with articulated arms that are movable along tracks, as well as all usual types of trash rack cleaners. Braun's largest trash rack cleaning machine with an articulated arm is employed at the Sohlstufe Lehen power plant in the center of the city of Salzburg. This machine is a showcase project in its own right as the parameters for dimension and total weight have broken many inhouse records.

Braun Maschinenfabrik GmbH's largest trash rack cleaning machine with an articulated arm is employed at the “Sohlstufe Lehen” power plant in Mozart's hometown.

LARGER – FARTHER – HEAVIER The trash rack cleaning machine with an articulated arm is a tool that moves along tracks

and consists of a traction and a rotary drive. The balance weight, the booth, the switchboard and the hydraulic power unit are assembled on the rotating upper operating console. The main arm has a total length of 14 m and a weight of 5 tons and is also attached to the upper operating console. The cleaner rake is attached together with the grabber to the lower end of the 12.3-m-long articulated arm. During the cleaning process the rake tines of the cleaner rake enter the fine rack. At this stage the grabber is open and will not close around the collected debris until it reaches

The product portfolio of the Upper Austrian hydraulic steel engineers offers the right cleaner solution for any power plant. Pictured here is a conventional cable winch machine that keeps the inlet of the power plant free from debris.

May 2015

the water surface. The grabber bottom is rotatable and is put into the initial position during the cleaning process. After the cleaning process is completed the grabber bottom on the upper end of the rake is slewed all the way up. The collected debris falls into the rake through this “spooning-like motion”. Then the grabber closes and the trash rack cleaner moves to the container. During the emptying process the grabber bottom is slewed all the way down and the debris falls out of the rake. In this position the grabber is securely holding on to debris of any size.

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Braun Maschinenfabrik has manufactured trash rack cleaners for decades and has become a reliable partner for large-scale as well as small-scale plant operators.

all photo credits: Braun

Smaller in design, but with the same reliable working performance as its “big brothers”: The telescopic arm trash rack cleaners of the power plant operated by the company Ludwig Hatschek AG, based in Vöcklabruck.

Between 2009 and 2014 many other extralarge trash rack cleaning machines with articulated arms were ordered by the German energy suppliers EnBW and LEW/BEW for equipping various power plants on the Danube and the Neckar River. An extraordinarily large unit is used at the Knochendorf power plant on the Neckar River. Braun designed a tailor-made unit with a cleaner rake breadth of 3.4 m. The complete cleaning breadth amounts to 30.6 m. The machine moves in both directions along tracks of a length of 39 m. The trash rack cleaner, which was installed by company experts, is designed for the fully automatic execution of 9 different cleaning positions. Trash rack cleaners with articulated arms have been part of the product portfolio of the

Upper Austrian hydraulic steel engineers since 2005. Braun has built an excellent reputation in the field of trash rack cleaners and has been successful with countless plants around the world. SMALL DESIGN – HUGE OUTPUT For some years now smaller hydropower plants have benefited from Braun's experience in the planning and execution of cleaning devices for large-scale plants. Because of the increase in orders by smallscale hydropower plant operators, Braun's engineers have adapted their collected knowhow of large-scale projects onto smaller power plants. The results are tailor-made telescopic arm trash rack cleaners offering the most reliable

cleaning performance and an excellent costperformance ratio, just as their “big brothers” do. The telescopic cleaners were first used in 2012 in Upper Austria, at the inlet channel of the small-scale hydropower plant of Ludwig Hatschek AG, where the old, wornout traveling screens had been replaced. The conclusion for the operator, one year after the cleaner was put into operation, is that the functionality of the telescopic arm trash rack cleaners is absolutely identical to that seen in larger plants. During fully automatic operations it keeps the protective rack, which is located at the inlet, free from debris and in this way contributes considerably to an undisturbed and smooth operation of the power plant.

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Gufler Metall KG, based in the Passeier Valley, South Tyrol, offers comprehensive services for all things hydraulic steel engineering.

all photo credits: Gufler

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SOUTH TYROLEAN HYDRAULIC STEEL ENGINEERS MEET ALL NEEDS Within the last two decades Gufler Metall KG, a company founded in 1991 in South Tyrol, has risen from a small business to a leading company in the field of hydraulic steel engineering. In the early years Gufler Metall focussed on forging, but has meanwhile shifted to delivering the most competent assistance for everything that has to do with hydraulic steel engineering, metal construction and penstock welding. The company has accumulated a long list of references in the recent past, having engaged in almost all hydropower plant projects in the South Tyrolean area. In the following we'll have a closer look at the product range of the hydraulic steel engineering experts. he Enerpass power plant was one of the biggest hydropower plant projects in South Tyrol in the last few years. For the installation of the penstocks the operators of the Enerpass power plant relied on the notable reputation of Gufler Metall, as so many other hydropower plant operators had counted on the company before. Having started off as a two-men operation, Gufler Metall over the years has gained an excellent reputation through a variety of many successfully realized projects. The company's knowhow surfaces in the planning, the execution and the installation of projects in almost all sections of the hydraulic steel engineering field, as the following overview of Gufler Metall's product range shows.

of a hydropower plant as they enable an exact regulation of the flow rate and the complete shut-off or damming of the water. The product range of the hydraulic steel engineering company, based in the Passeier Valley, is very extensive, consisting of slide gates, roller gates, double flood gates and sluice gates with attached flap gates. Larger weirs are often provided with flap gates of different sizes, the most common version being the fish belly flap gate. These gates are powered by hydraulic cylinders and hydraulic power units using biodegradable oil. The flood gates and the flap gates are robust in construction and built with high-quality steel to ensure long life and stout sealing.

FLOOD GATES AND FLAP GATES Flood gates are shut-off and control devices. They are important for the smooth operation

PENSTOCK PROTECTION VALVES In an emergency penstock protection valves prevent huge or even irreparable damage to

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the machine unit through a quick intervention. Gufler Metall's penstock protection valves make sure the electromechanical gear does not suffer damage when water leaks. In an emergency situation a falling weight is activated within seconds through a reliable mechanical release mechanism setting off a hydraulic closing dynamic, which then locks down the process water channel. Gufler Metall's penstock protection valves are delivered ready-for-assembly with inlet cone, bypass and junctions for ventilation. TRASH RACK CLEANERS In most cases an inlet trash rack needs an appropriate cleaning device in order to guarantee a smooth operation. Gufler Metall's sturdy trash rack cleaners are the best solution for protective racks of all kinds. The company offers trash rack cleaners with a single or multiple telescopic arm design as well as

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cleaners with an articulated arm. Customers can choose between electromechanical and hydraulic power units using biodegradable oil, just as with the flood gates and the flap gates. The power units are built into unobtrusive switchboards. Depending on the customer's requirements the movable parts of the trash rack cleaner will be provided as crude steel, steel with protective coating or galvanized steel. Moreover the hydraulic steel engineering company offers racks for classic Tyrolean weirs with gap spacings of various dimensions. The rack design can be executed in extra-robust wear-resistant layers as well as with integrated plates for the residual flow. As for the material customers have a choice of crude steel, hot-dip galvanized or stainless steel. COANDA TRASH RACKS Operators in modern Alpine small-scale hydropower plants turn more and more to Coanda trash racks for sediment deposition systems. In most hydropower projects these protective racks are installed into the weir plant after the coarse rack. Their self-cleaning operating technology can also be used as maintenance-free protective filter for penstocks of all kinds. The installation of a Coanda rack can considerably reduce plant, operation and maintenance costs. These racks are available in various dimensions and are made of stainless steel. They are mainly used with flowing waters, whether a water catchment is newly built or simply remodelled. The narrow rack bar spacing and the eponymous Coanda-effect reliably keep any sediment particles of 0.5 mm in diameter or higher out of delicate machinery parts, thus preventing plugging and damage. The operation of a Coanda trash rack is not even affected by frosty temperatures of -25째 Celsius, as many of

Hydraulic steel engineering components have to resist powerful forces in Alpine terrain. Certified Gufler Metall experts provide a top-quality performance.

The Coanda trash racks run without an additional rack cleaner due to an integrated self-cleaning effect.

Gufler Metall's reference projects, which have been in operation for more than twenty years without any problems, can prove. TOP SERVICE BY TOP PROFESSIONALS Family-run Gufler Metall, now employing a total of 15 people, links its steady success to two interdependent key aspects. One is kee-

ping customer satisfaction at a maximum by successfully combining high-quality on-time services with a fair cost performance ratio. The second aspect is having jobs only performed by top-qualified experts, whom the founding members, brothers Alfred and Gothard Gufler, call their most valuable resource.

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photo credits: Muhr

An innovative alternative to horizontal trash rack systems: RO-TEC screen drums by Muhr.

SCREEN DRUMS MAKE POWER PLANT OPERATORS’ HEARTS BEAT FASTER Well known for their reliable hydropower systems, solution provider Muhr introduces a new, innovative protective screen drum system as the latest addition to their extensive product range. As an alternative to horizontal trash rack systems, the Bavarian-based company’s patented RO-TEC screen drums combine high efficiency with optimum installation and maintenance characteristics while ensuring ecological compatibility.

he way the Muhr screen drums work is simple, yet extremely efficient. The screen drum consists of a cylindrical trash rack screen that rotates about its central axis. A built-in electric motor unit keeps the drum in constant rotary motion. This causes the collected floating debris to be pushed towards a wiping strip, where it is washed away by the drag flow, resulting in a selfcleaning effect. As it integrates easily into existing facilities without the need for extensive constructional work, the drum system with its self-cleaning capabilities helps to save costs and effort when it comes to debris removal. Another welcome characteristic of the new

May 2015

technology is its high level of fail-safety, as each drum unit is equipped with its own motor, which allows it to operate independently from other units. Naturally, the motor units are 100 per cent watertight, which means the entire screen drum system can be flooded without risk of damage. BENEFITS FOR OPERATORS Aside from smooth, trouble-free operation, a key requirement for operators is that the units must be easy to service and maintain. This is why ease of maintenance was a top priority in the design of this brand-new protective screen drum system. As a result, the

drums are not only quick and easy to install, they can be removed just as easily for maintenance purposes. This way, any repair work – although unlikely to be necessary, thanks to the use of durable technology and only few moving parts – can be performed safely and conveniently “on dry land”. In the meantime, stop logs can be fitted to the drum’s guide rails to ensure continuous operation of the facility. Another big plus of the new drums is the extremely short installation procedure. Delivered by lorry, the units are lifted onto the guide rails (these must be provided in advance at the building site) and installed properly

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photo credits: Muhr

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by Muhr technicians. The entire procedure takes no longer than 60 minutes. Once installed and electrically connected, the drums are ready to go. SCREEN DRUMS MADE TO MEASURE Depending on individual project requirements, the screeen drums can be custom manufactured to suit the operator’s needs. Screen Drum sizes range between 500 mm and 2.800 mm in diameter and 500 mm to 10.000 mm in height. The screens are made from galvanised highgrade steel and are available in slot widths from 2 mm to more than 50 mm. Operators can choose from a variety of grid profiles, depending on the slot width and ambient conditions at the installation site. A potentially unlimited number of drums can be combined into a single screening system to accommodate facilities of any size. The RO-TEC drums are suitable for water sampling points of any kind, cooling water and process water treatment plants, and, of course, hydropower facilities. ECOLOGICALLY SUPERIOR ‘Fish friendliness’ is another beneficial feature of the screen drum. Thanks to the specially designed screen profile, water-based animals cannot get caught in the device or sustain injuries from sharp edges. Also, the round, drum-shaped design provides about 1.5 times the surface area of standard screens, which reduces the water flow velocity around the device. This means a considerably lower risk of fish being sucked into the system. With its low construction height, the components of this patented screen system also integrate smoothly into existing river landscape. What is more, the resource-saving operation of the device requires no oils or other lubricants, which eliminates the need for the disposal of problematic waste.

The screen drum suits many applications, combining well-designed technology and ecological compatibility. Thanks to their compact design, the screen drums integrate smoothly into existing facilities.

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SUCCESS FOR AUSTRIAN MECHANICAL ENGINEERING SUPPLIER IN WEIR STRUCTURE PROJECT

o matter what the customer requirements, Danner Maschinenbau GmbH construct and manufacture all their hydropower weir gate components in-house. This includes everything from weir baffles and radial gates with attached control flaps to various kinds of sliding or roller gates. Over the years, the mechanical engineering firm with its team of 58 employees has built up a reputation that reaches well beyond Upper Austria. Today, more than 400 customers from Austria and abroad rely on their extensive technical knowledge and experience. Apart from facilities in Austria, numerous power plants in Italy, Hungary, Bulgaria, Romania, the Czech Republic and Iceland carry the hallmark of Danner technology. 40 M WEIR OVERFLOW IN THE STODERTAL

A perfect example of how to integrate a power plant into the surrounding landscape is the Tambergau facility, located not far from Petten-bach in the Hinterstoder region. Here, the water proceeds from the intake at the naturally designed overflow crest to a nonpressure channel and on to the power house, which resembles a residential building. In 2008 Danner manufactured and installed a wide range of equipment for the power station, which has a standard capacity of between 2.5 and 3 GWh. The items delivered and installed included, among others, a flap gate, a discharge sluicegate, the segmental valve, the intake gate for the residual water turbine, the steel lining of the stilling basin, and the fine rack. Danner also renovated the existing gate structure in the non-pressure channel to put it back into good working order.

The weir gate, blending smoothly into the landscape in the Hinterstoder region in Upper Austria.

SUCCESSFUL HIGH-WATER CONCEPT Hydropower plant Möderbrugg in the Pölstal region in the Austrian province of Styria was equipped by Danner with a massive fish belly gate, which also eliminated residents’ concerns about possible floods. A gate measuring 14 m x 4 m was constructed and installed to ensure an efficient discharge of flood water. The entire structure is designed for discharging the water of floods with a return period of 150 years. Overall, around 2,000 cubic metres of concrete were used for weir construction alone. In addition, Danner also supplied the entire hydraulic steelwork structures, including the spillway gate with attached weir baffle and the intake and fish pass gates, as well as a fully automated telescopic trash rack cleaner. Hydropower plant Möderbrugg was connected to the grid in October 2013 and generates around 7 GWh of clean energy per year. THE BIG CHALLENGE: FLOOD PROTECTION Working on a hydropower project in Hauzenberg in Bavaria, Germany, Danner technicians were faced with the challenge of developing a functional control flap solution to help protect the industrial premises some 500 m further downstream from possible floods. For this purpose, the old overflow crest is soon to be replaced by a new, hydraulically operated control flap. As the water level was required not to rise, this led to a device with rather extreme proportions: 16 m in length and just 0.8 m high. For the Danner technicians, this meant they had to come up with a highly solid, torsion resistant solution. So in August 2014 they went into high gear, working a busy schedule at the production site in Pettenbach to complete the control gate. This contract once again underscores the ability of Danner Maschienenbau GmbH to master the most complex of requirements. Another Danner masterpiece: the massive fish-belly gate that protects residents in the Styrian Möderbrugg region from future floods.

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all photo credits: Danner

Headquartered in Pettenbach in Upper Austria, Danner Maschinenbau GmbH has been serving a growing base of satisfied customers since its foundation in 1980. Whether with their turbines, hydrodynamic screws, hydraulic steelwork engineering or revitalisation work, Danner’s team of technicians have consistently lived up to their customers’ expectations. They have also proven their experience and know-how in weir gate systems, which allows them to provide ideal solutions to suit any facility. By now, word of this high level of professional performance has spread beyond Austria.

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DESANDER SYSTEMS FOR HYDROPOWER PLANTS – STATE OF THE ART Patented removal HSR systems have been convincing customers of their safety, economic viability, efficiency and operational reliability ever since 2001, as has been proven by the installation of over 61 desander plants in Switzerland, Austria and Italy. The HSR sander removal system is employed at small power stations, large water catchment plants, gravel rinsing channels and for several other special applications. Their implementation in renovation projects has also been shown to be successful in increasing efficiency.

REQUIREMENTS FOR POWER STATION FACILITIES Modern power station facilities have to adapt to the needs of the market. They must be safe for customers, conform to general standards, and offer operational reliability, availability and serviceability. They also have to meet client requirements, legal requirements, product and work safety standards, and be – and remain – in good working order. Optimised lifecycle expenditure has to be achieved with a minimum of investment, high efficiency and low costs of operation and maintenance.

graphics: HSR

he system meets operator requirements for large-scale plants with immense sediment precipitation; as well as in smaller plants and for the renovation of existing infrastructure. Several benefits have come to the fore, such as a very limited degree of wear, despite dealing with extreme loads; lower maintenance costs and work, while guaranteeing a higher degree of operational reliability; significantly improved safety due to a reduction of the susceptibility to buildup surges in the preflood channels, complete control of the rinsing process and a large degree of acceptance among the authorities responsible for granting licenses due to a reduction of negative environmental impact to an absolute minimum. Fully automated, monitored, remote control systems offer reliable solutions for

Typical water catchment equipment at a small-scale power station with removal pipe, sediment gauge and rinse feeder

REQUIREMENTS FOR DESANDER SYSTEMS AND DESANDER EQUIPMENT Desander systems are expected to remove the greatest possible amount of sediment from water passing through the plant. Rinsing channels and gravel removal devices often have to deal with very large sediment granule sizes. Furthermore, desander basins also have to remove very fine sedimentation. Almost all of this work is done in a long and narrow above-ground sand catchment channel that runs along the preflood basin and rinses in the same direction as the main flow; or below-ground in excavated rock caverns with rinsing against the direction of the water catchment. In both cases a small cross-section desander can raise the shaft in the rinsing channel and lower building costs. The crosssection of sedimentation is determined by the structures of the hydro-plant. An efficient removal system can reduce the cross-section of sediment and the rinsing pipe can be positioned in a fairly high position. In combination with simple basin shapes, it is possible to achieve significant construction cost savings and implementation can be seen to be viable in various projects.

inaccessible plants, for the reduction of staffing expenses and compliance with environmental and safety directives. The HSR sand removal system stands up to the extreme abrasion generated by alpine stream catchments. Furthermore, it meets the current requirements of plant operators in terms of economical operation and minimisation of maintenance costs. Large-scale projects in Austria:

Tumpen-Habichen power station: 6 sediment removal pipes DN 600 x 42.5m desander • 1 sediment removal pipe DN 600 x 60m gravel rinsing channel

photo credits: HSR

Water catchment at Stanzertal power station: • 3 Sediment-Abzugrohre DN 600 x 44m, 3 x 2 sediment gauging devices •

Large water catchment with extremely large amounts of abrasive sediment. Surges have been reduced to a safe level by rinsing.

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A comparison of a cross section of a conventional desander basin with the opportunities opened up by the installation of an HSR sediment removal system: Digging and excavation savings, significantly higher positioning of the rinsing pipe. This makes it possible to install rinsing pipelines, even in very flat terrain.

For reasons of safety and environmental protection it is necessary to be sure the preflooding basin is supplied in a careful and controlled manner. Minimal amounts of rinsing water and controlled concentrations of sediment, combined with flexible and adaptable automated controls, both remote and on site, are now realistic aims. Operations can completely avoid rinsing during the daytime and supply water to the preflooding basin gently and in a biologically friendly manner. Modern operative management requires maintenance and replacement to be conducted without downtime. Electro-technical devices are expected to be maintained and made operable with as little interruption, effort and expenditure as possible. Inspections and cleaning work need to be carried out with the necessary efficiency, while also corresponding with current work safety standards. Today, many moving electrical, hydraulic and mechanical components in desanding basins that deal with water with high concentrations of sediment, no longer meet all the latest specifications as regards reliability, availability, maintenance and safety. Flushing gates often require special technical set-ups.

photo credits: HSR

PATENTED SEDIMENT REMOVAL SYSTEM HSR The HSR sediment removal system was developed as a customised welded construction and was optimised during a series of elaborate hydraulic model tests. The diameter is selected according to the overall dimensions. In practice, in the majority of cases this involves the installation of removal systems with a diameter of 600mm. There are standardised solutions with a diameter of 800mm for larger desanders and also smaller 400mm diameter standardised solutions.

Efficient sediment removal with affordable construction and safe inspection access.

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Based on the scale model experiments it was possible to reduce the amount of water required for rinsing to less than 20% of the volume needed by a conventional narrow rinsing channel, so for most versions of the preflooding basin, there is no need for alert-water. The resultant saving of rinsing water can rise to over 90%. The removal pipes can be placed in a desander basin with a square crosssection without a drop in efficiency. This provides a simple, low-cost, high-volume desanding chamber with a minimal excavation section, or a higher installation height with less digging required. In the corners above the rinsing pipe and on the opposite side, dependent upon the angle of precipitation, there are persistent sloping sediment deposits. The rinsing and emptying processes do not remove them completely. However, for the ongoing removal of sediment this is not an issue. An ideal and clean solution is the setting in concrete of a 45° slope along the removal pipe. An extension pipe is required in the removal units for cleaning purposes. The sediment removal pipes can be operated and maintained simply and cheaply. Repairs and replacements can be done easily and without great effort or expense. The sediment removal elements enable the sediment basin to be designed in such a way as to allow easy access; and maintenance can be conducted in a hazard-free environment. The removal system consists of the following parts: • Steel pipe (cone) connector integrated during construction and linking up to the rinsing pipe • Extension pipe for viable servicing opportunities • Modular rinsing pipe with evenly spaced rinsing chambers • Adjustable lid to fine-tune the rinsing jet openings Rehabilitation is possible by new rinsing chests and cover plates installed in the rinsing slot with a minimum of adaptive work. It has been designed in such a way as to allow problem-free installation in the narrow rinsing channels. The rinsing pipe and rinsing chest are designed in such a way as to facilitate the following functions: • Opening the rinsing organ triggers the rinsing process • A hydraulic switch effect triggers the removal process • The systematically established turbulent flow makes it possible to increase drag speed without additional loss • The rinser can be directed from the initial opening to the rinsing opening, and closed once rinsing has been completed. Improvement in the efficiency and operational availability of a desander with worn out blades: HSR sediment removal and low/no-wear base plates for the restoration of the base and corners.

photo credits: HSR

graphics: HSR

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In the case of desanders with a concrete ceiling, a maintenance hatch with an opening large enough for installation and servicing work is an imperative recommendation. This also goes for assembly and installation aids on the desander roof. The opening is designed to enable the installation of a rinsing pipe. HSR sediment removal systems can also be built into gravel removal systems, gravel rinsing channels, driftwood and flotsam collectors, equalising basins and cold water basins. It can cope with stones up to the size of those used under railway tracks, and even larger stones if covered by sufficient water. FLUSHING GATES Good experiences have been made with low-cost, rust-free plate feed rods with self-cleaning guide grooves and covered seals. Minimal lifecycle costs can be achieved when replacement servicing is carried out. For heavy duty usage there are high performance rinsing feeders with self-cleaning guide grooves and non-rusting, well protected sealing surfaces. Robust hydraulic engines drive the feeders very effectively.

photo credits: HSR

There are two distinct rinsing procedures: • Rinsing procedure during operation (automatic operation possible): Uninterrupted catchment: Maximum efficiency of solid material removal using the least possible volume of water. To ensure full use is made of the sediment removal system it is necessary to be equipped with a rinsing pusher that can be set to operate at a suitably high speed. • Emptying procedures (can also be done via remote control). Complete removal of all solids (according to the shape of the settling basin). This rinsing process is used when the water catchment system is switched off, to empty the precipitation basin, to ensure subsequent distribution of the preflooding basin, and for inspections.

Modern, low-cost sediment gauging device.

to be light and easily replaced. Modern manufacturing methods enable the production of robust and affordable grids of non-rusting steel, thus fulfilling all current product safety and work safety requirements.

SEDIMENT GAUGING Full capacity vibration probes meet today’s maintenance requirements very cost effectively. There is no need to install underwater devices whatsoever. The probes can be serviced and replaced without interrupting operation or lowering water levels. Access shafts to sediment gauging devices are highly recommended.

WATER DISCHARGE FACILITIES A constant water level and the correct placement of low-sediment-content water allow logically calculated and precise water discharge facilities for preflood channels and basins. Seasonal adaptions to discharge volumes are achieved simply. Compensation of rinsing water loss can be managed with the necessary effort. Separate water discharge facilities are more economically viable and provide clearer and exacter records of the amount of water discharged in comparison with direct discharge via the sediment removal facilities.

STILLING GRIDS Sedimentation basins react very sensitively to sudden additions to flow volumes. For this reason stilling grids are mostly installed at the end of a sloping inflow cone. The components can suffer damage if filling is too rapid or if there are sudden cloudbursts. The individual parts have

ADDITIONAL EQUIPMENT Steps and access facilities enable maintenance work and inspections to be conducted safely. Inspection hatches, built-in lifting gear and the corresponding design of desander basins and sediment removal infrastructure make servicing a safe job.