BYSTRUP
POWER PYLONS OF THE FUTURE
2
24 Bystrup CEO Henrik Skouboe on making it happen
36
44
Prototypes of the suspension and the tension pylons.
Creating an object that balances aesthetic appearance and technical optimisation
CONTENT 03
A Global Challenge
24
Making It Happen
38
T-Pylon
04
Introduction
26
Erected in a Day...
RGI
40
Optimising
06
One Day, one Team, one Pylon
Renewable-Grid-Initiative
28
Lifespan
42
Acting Responsibly
10
Grid Expo
30
Mirror Wall
44
Composite Pylon
12
Design Pylon
32
Time for T
And the Winner is...
48
Before and After
36
Developing the T-Pylon
50
Life at BYSTRUP
that Needs Local Solutions
The Beginning of a New Era
18
The Eagle Pylon
20
Backbone
of The Danish Transmission Grid
Interview with Henrik Skouboe
Reflecting the Environment
Contemporary and Sustainable Technical Performance
Significantly Smaller Improving an Existing Line Q&A: Simon Harker MAA MEng
Editorial: Line Herdel, Anne Brunsgaard Photo: Ole Christensen, Erik Egvad Petersen, Petteri Salokannel, Michel van Steenwijk Contact: bystrup@bystrup.dk
3
A GLOBAL CHALLENGE THAT NEEDS LOCAL SOLUTIONS Electricity is regarded a basic necessity. Without electricity, the laptop, the stove and the game console do not work. In the transition to renewable energies, new power lines are required. For the past decade, we have worked intensively with the infrastructure and aesthetics of overhead power lines. By combining the advantages of new technologies and new materials, we are able to ease the working process and create a platform for innovation as well as a positive public perception. After years of constant progress, two new transmission lines have been completed in Denmark, and a third line is rapidly progressing in the UK. Knowledge meets aesthetics in the creative process of designing the future power lines. We are pleased to share the knowledge and experience we have acquired over the past decade with you.
Erik Bystrup
5
INTRODUCTION This publication updates you on BYSTRUP’s latest power pylon design. Current demands of transporting carbon neutral or renewable energy over significant distances call for a substantial modification and expansion of the power grid. When designing the future power pylons, it is necessary to widen the focus. New lines are needed all over Europe, but new lines are often met with massive protests. In Europe, Transmission System Operators (TSOs) are under pressure to meet not only the technical and economic challenges of future power transmission, but also the concerns of the public.
This publication reflects upon BYSTRUP’s approach to power pylon development. Included are three successive realised projects - from the pylon that started it all to our current mission. You will find contributions from the European association RGI (Renewable-Grid-Initiative), Norwegian TSO Stattnet, Danish Energinet.dk and British TSO National Grid. In a series of articles on future power lines, BYSTRUP adresses topics such as: foundation principles, erecting speed, stringing tools and optimisation of lifespan.
6
Facts from Europe: More than 30,000 miles of European transmission grid is needed over the next 10 years. This equates to over 100 transmission projects across Europe in the coming decade. 40 percent of the projects are interconnectors. In the coming 10 years, € 104 billion need to be invested in Europe, € 23 billions are for undersea cables. In Germany alone € 30 billions are needed, and in Great Britain the number is almost € 20 billions. 1) This is the best available information to date. Figures however keep adjusting for every project and the information is subject to changes for every country. 2) TSOs invest beyond projects of pan-European significance at regional or national level. Source: www.entsoe.eu Ten-Year Network Development Plan
RGI
RENEWABLE-GRID-INITIATIVE greenhouse gas emissions, more energy efficiency, and an increased share of renewable energy. This change will have tremendous effects on the geography and time horizons for planning and implementing new electricity infrastructure.
By Antonella Battaglini, Executive Director, Renewables-Grid-Initiative
New thinking and new alliances are required to meet the challenges posed by increasing energy needs and climate change. Europe is in the middle of a substantial transformation of its energy system. In order to fight climate change, a strategy has been developed consisting of three pillars: a reduction of
To fully integrate renewable energy from centralised and decentralised sources, Europe´s grid architecture needs to be adapted and expanded to allow transmission over long distances, across national borders, and from generation to consumption and storage sites. Thousands of kilometres of new lines need to be built today and in coming decades. However, public opposition is growing. To overcome this opposition, new alliances across society are needed. It is necessary to bring more
8
transparency to the grid business, to further develop participatory procedures and to redefine roles which have been performed over the past decades. For the first time, the Renewables-Grid-Initiative (RGI) has provided a forum, in which Transmission System Operators (TSOs) and nongovernmental organisations (NGOs) can practice their new roles. RGI was launched in July 2009 by a coalition of four members - two TSOs and two NGOs. For the first time, these two groups defined their common interest in the 100%-integration of renewable electricity into the European grid and committed themselves to working together. Since then, RGI has grown to include 15 members from all over Europe and has become a respected and trusted partner.
The “European Grid Declaration on Electricity Network Development and Nature Conservation in Europe” was handed to European Commissioner for Energy Günther H. Oettinger on 10 November 2011 at the European Grid Conference in Brussels.
TSOs have learned that they need to overcome the “business as usual” approach and respond to the new situation in a flexible way. Civil society, on the other hand, recognises that it needs to inspire the transformation, explain it and help build support among the general public. Both parties have built up trust among each other, exchanged their views
and experiences, and started to cooperate. A major step for this cooperation was the publication of the “European Grid Declaration on Electricity Network Development and Nature Conservation in Europe” in November 2011. To date, this document has been signed by 30 signatories, including nine
of Europe’s largest TSOs and Europe’s major environmental NGOs. The Declaration has been broadly perceived as a unique success in shifting the game from “opposition” towards “cooperation”. It defines a set of principles for building the grid in line with Europe’s objectives for nature conservation and climate change mitigation. In 2012, principles regarding transparency and public participation were added. Building on commitments made in the “European Grid Declaration”, RGI initiated an exchange of best practices in grid expansion projects across Europe in 2012. The project enhances and stimulates the exchange of ideas and lessons on better practice in order to support a swifter implementation of successfully proven concepts.
The close cooperation between grid operators and civil society during the past four years has shown that unexpected success can be achieved if different stakeholder groups team up. However, some challenges still remain unsolved. The diverging actors involved in grid planning still lack common ground on a variety of topics. Joint understanding of challenges and approaches need to be developed and agreed upon by TSOs, NGOs and further stakeholders. RGI will keep up its work to support this process. For more information: www.renewables-grid.eu From the left: Janez Potocnik, Commissioner for the Environment (European Commission) Guido Axmann, Managing Director of THEMA1, Kristina Steenbock, Executive Director of SEFEP, Günther H. Oettinger, Commissioner for Energy (European Commission) Antonella Battaglini, Executive Director of RGI at Grid Expo.
10
GRID EXPO GRID EXPO is a touring exhibition showcasing pioneering pylon design. Current grid discussions are either highly techno-bureaucratic or ideologically polarised. To create a receptive mindset the public debate has to become emotional and exciting. Grids have to become “our business” instead of “our problem”. The GRID EXPO project aims to bring fresh impetus to the dialogue by acting as radical mind-opener and triggering new, ground-breaking, and visionary discussions amongst stakeholders and the general public. Hand in hand with the energy system’s gradual transformation into a sustainable one, the future grid needs to fully benefit the society, also in aesthetic terms.
The GRID EXPO is a pledge for an innovative grid system manifestly contrasting with the current one. Tomorrow´s society shall not be ashamed of its electricity system but fully embrace it. Besides the exhibition element of the GRID EXPO project - containing pylon models, large scale prints and installations, accompanying GRIDSPECTIVES Dialogue Forums are held that address different issues with regard to the contents. GRIDSPECTIVES is about grids and perspectives; new perspectives. It confronts traditional views with new insights. It reveals the gaps between politics and society as well as between theory and reality. It lets new paradigms evolve and fosters controversial discussions.
12
Energy experts encounter cultural innovators. It is a safe environment for unconventional debates. It is open and fresh – and certainly not boring. The vast interest in the 1st GRIDSPECTIVES Dialogue Forum, held in April 2013 in Berlin, showed that it definitely is a topic of interest for people from many different sectors. For more information: www.gridexpo.eu
The 2013 GRID EXPO program: • Brussels, 05 December 2012, Kickoff at 2nd European Grid Conference with EU commissioners Günther H. Oettinger and Janez Potočnik • Zurich, 13-14 February 2013, GRID EXPO at Renewables-GridInitiative Cable Workshop • Hannover, 05-09 March 2013, GRID EXPO at CeBIT • Berlin, April – December 2013, GRID EXPO „Beauty of Power“ at Projektzentrum Stiftung Mercator • Berlin, 22 April 2013, Gridspectives Design Forum at Projektzentrum Stiftung Mercator • In planning: GRID EXPO in Amsterdam, Berlin, Brussels, London, Paris, Oslo, Rome, Zurich.
DESIGN PYLON
THE BEGINNING OF A NEW ERA steel tubes. By grouping the conductors in a triangular cross section, the electromagnetic field is minimised. As a result, the Design Pylon is distinctive, simple and functional. The line was completed and energised in 2004.
Henning Øbro, Senior Executive Project Manager, Energinet.dk
In 2001, the Design Pylon was awarded first prize in an international competition organised by Danish TSO Energinet.dk and the Ministry of Environment and Energy. As the name “Design Pylon” suggests, the main focus of the competition was originally on aesthetics. The power line is designed as a row of monopile structures with filigree lattice heads in stainless
“Locals were involved in the whole process and have embraced the new pylons calling them Magic Wands”. Designing a pylon The overall design strategy for the new 400kV tower was to design a tower that would eliminate “visual noise”. The pylon is reduced to a few elements calmly traversing the landscape. During the material selection, several options were investigated. The final choice was hot-dip galvanised steel for the shaft and stainless steel for the lattice top. 14
The lattice head is constructed of stainless steel tubes joined by cast nodes: a simple and fast assembly method.
The Pylon Family Three types of tower were developed: • Suspension tower • Flying angle tower for maxi- mum 5o deviation • Angle tension tower for 5o to 45o deviation A prototype of the suspension tower was constructed and mechanically tested to 105 percent of the maximum design loads. Foundation The foundation - a steel pipe of 1.5 metres in diameter, 22 milimetres thick, and 7 to 11 metres in length - is driven into the ground by a hydrohammer of 9.2 tons. The working time for this operation is approximately 30 minutes per monopile.
The monopile is rammed 8-10 meters into the ground depending on the soil conditions. Then the shaft is mounted and grout is cast between the two parts. Compared to a traditional concrete gravity foundation a monopile foundation is highly efficient and cost-effective. Erection of Pylons The new design concept for shaft and foundation has proven very advantageous when erecting the pylons.
16
The shaft sections are assembled on the ground and erected by a mobile crane. The lattice head is assembled, then lifted up by a mobile crane and bolted to the shaft. Insulators and stringing accessories are mounted. The whole process is completed in a few hours.
The new 400 kV pylon: • Minimal footprint • Fast in situ assembly • Straight-forward and inexpensive foundation method
Technical Experiences During the design and construction process many issues had to be addressed. Casting of Stainless Steel Joints The moulds for the castings were manufactured as part of the development project and were used for the prototype as well as for the production of the remaining tower tops. Vibration of Tower Head Elements Vibrations were foreseen as a potential problem. Theoretical analyses showed that some parts were subject to unacceptable levels of vibration. To eliminate the problem, the outside diameter of the given tubes was reduced in order to change its dynamic properties and behaviour.
19
Furthermore, the prototype of the lattice head was manufactured and tested. As expected, the result was very low values with logarithmic decrement below 1 percent. The parts that were the most susceptible to vibrations were fixed by drilling holes at the front and back of the central part. Wind tunnel tests as well as subsequent measurements on the erected prototype were used to calculate the improvement in lifetime. The analysis showed an increased factor of more than 30, which was fully satisfying. For more information: www.energinet.dk
THE EAGLE PYLON
Brian Endahl, Senior Development Manager, BYSTRUP
After completing the Design Pylon, BYSTRUP was commisioned to develop a double circuit power line for Danish TSO Energinet.dk in 2006.
Due to the integration of an increased amount of wind energy into the power system it is neccessary to expand the grid. By 2014, the Danish power supply will be upgraded with 514 new Eagle Pylons in a new and stronger 400 kV line which connects Germany to Norway and Sweden. This is known as: “the Backbone of Denmark”. 20
“When developing the Eagle Pylon for Danish Energinet.dk, we put great emphasis on the overall appearance. The pylon is designed as a shaft with four arms reaching for the sky”.
The new connection is built along the existing line of lattice towers, which will be removed as soon as the new connection is operational. The high-voltage line is a vital energy transport route in the Danish power system.
The new, stronger power line is a key element in Denmark’s ambitious energy policy. It ensures that a large part of power is generated using renewables.
With the power links to Norway, Sweden, Germany, and possibly the Netherlands, the new line will ensure that Denmark is able to import electricity from neighbouring countries.
Energinet.dk must offer alternatives to wind energy, when wind turbines are not generating power.
The power line will also be used for exporting electricity in the periods when electricity consumption is lower than the wind power production.
21
BACKBONE
OF THE DANISH TRANSMISSION GRID As a consequence of the Danish energy policy all future lines below 100 kV will be underground. Most of the 400 kV lines will still be established as overhead lines.
By Christian Jensen, Executive Project Manager, Energinet.dk
A 400 kV overhead line with double circuits will be completed in 2014. This line is the backbone of the Danish transmission grid and will connect Germany to Norway and Sweden. The existing single circuit line will be replaced by a new line carrying double circuits. Due to severe public opposition against the lattice towers, new design pylons will be used for future overhead lines.
22
New Pylons The vision is to create a new line which is calm, elegant and light. The pylon is a structure based on a cylindric shaft and rhombus shaped cross-arms. The rhombus shape makes the cross-arms appear very slim. The new design consists of suspension towers, flying angle towers, tension angle towers and dead-end tension towers. The three different types have the same overall expression. Where the line either ends or changes to underground cabling, a substation is established and terminal tension towers are used.
The new pylon has shown that it is possible to rethink the design and the general approach to overhead lines - and to receive positive feed-back
Substations To handle the transition from overhead to underground characteristic stations have been developed and constructed with design features matching the rest of the pylon family.
Acceptance The first public hearing, where different tower types and ideas were presented, was held in June 2009. In the second public hearing in March 2010, the final design was presented and the public was asked to share their opinions and views on specific alternatives. The public feedback was overall positive towards the new design.
Visual Appearance The maximum span is 360 metres. A small amount of angle towers are used in order to provide a calm expression. Different heights of suspension towers are used, so they - from a distance - appear to have the same elevation despite the terrain profile.
After starting the construction work in January 2012, the neighbours have accepted the towers and quite a lot of them are fascinated and proud of the new design. There have been very few problems so far. Construction The first 50 kilometres were completed in February 2013. The next 50 kilometres will be completed by the end of 2013 24
and one year later the entire line of 514 pylons will be energised. All phases of construction have proceede smoothly. General experience The new line has been well received by neighbours, experts, contractors and by Energinet.dk. The realisation of the Eagle power line has shown that it is possible to rethink the design and the general approach to overhead lines - and to receive positive feedback. For more information: www.energinet.dk
The Eagle Pylon Line: The new line consists of 166 km overhead line and 8.6 underground cabling. It will be completed and put into operation in three stages: 55 km in 2012 51 km in 2013 68 km in 2014 The capacity of the line will be increased from approximately 1150 mega watts to 2x 1800 mega watts. The Eagle Pylons will be placed with an average interval of 330 metres. In comparison to the old line, 35 per cent fewer homes will be affected by the new line within a distance of 80 metres.
MAKING IT HAPPEN
INTERVIEW WITH HENRIK SKOUBOE For example, we have analysed the national code of practice regarding galloping in cooporation with Danish TSO, Energinet.dk, and documented through advanced simulations that the precautionary distance could be significantly reduced. The result was a more compact and lighter pylon at a lower cost. Henrik Skouboe, CEO, Bystrup
Developing power pylons for the future means creating objects that balance aesthetic appearance and technical optimisation. In the design process, complex 3D geometries must be managed. The technical demands and handling of high-voltage clearances require thorough knowledge of rules, regulations and standards.
In regard to the development of the T-Pylon, we have investigated the use of SG iron in the nodes. SG iron has ductile qualities that make the material suitable in relation to fatigue assessments. Logistics, simplicity and speed of construction are determining factors in our aim to produce competitive and economically efficient power pylons. Until now, one of the great challenges of conventional towers has been the actual assembling and mounting. 26
“We are capable of dimensioning all components and performing structural, as well as dynamic analysis of the entire pylon�. The lattice tower consists of numerous parts which take time to assemble in the field. The new pylons consist of very few parts that arrive on site ready to be mounted. Up to two pylons per day can be erected by a team of maximum five people. The result is a considerable reduction in the overall mounting time. These are a few examples of the many challenges we analyse and tackle. Our aim is to continuously create qualified and less expensive solutions.
ERECTED IN A DAY...
ONE DAY, ONE TEAM, ONE PYLON Foundations for offshore windmills are typically made with monopiles driven into the seabed. The same type of foundations can be used for towers ashore. The method has proven to be fast and effective. The footprint of the foundation is very small compared to concrete plate foundations. The environmental impact is subsequently smaller, and due to very limited excavation, ground water problems are practically eliminated. The sections of the tubular shaft and the cross-arms are installed very fast. A mobile crane is used for erection. Minimum one tower is completed per day by a single team.
28
LIFESPAN
Hot-dip galvanised Steel is a wellknown and highly used material. When utilised for power pylons it has a lifespan of approximately 45 years. Hot-dip galvanised steel is coated with a zinc layer, up to 200 my, by passing the metal through a molten bath of zinc at a temperature of around 860 째F (460 째C). When exposed to the atmosphere, the zinc reacts with oxygen to form zinc carbonate, a fairly resistant material that stops corrosion.
Weathering Steel also known as Corten Steel is maintenance free over time and is practically imperishable when used for pylons. It blends well into the landscape with its earth colours and is a fairly inexpensive material for power pylons.
Stainless Steel is practically indestructible. The material needs very little maintenance. However, stainless steel is an expensive material, and the best solution is to work with a combination of structural steel and a protective layer of stainless steel.
Corten Steel oxidises to a robust protective layer with a rust-like appearance if exposed to the weather.
The stainless steel can be treated to reach different degrees of reflection. The stainless steel mirror-surfaces provide an illusion of the pylon merging into the environment.
31
MIRROR WALL REFLECTING THE ENVIRONMENT The Jury’s Assessment: The sculpture pylon measuring 34.5 metres in height and 32.5 metres in width stands as an illustra on of the beau ful landscape at Heia. It is a tes mony to nature being a sensa on in itself at this par cular place.
Håkon Borgen, jury chairman Executive Vice President, Statnett.
The Mirror Wall from the Danish company Bystrup won the compeƟƟon to design StatneƩ’s first sculpture pylon. The pylon is going to be placed at Heia in Troms as part of Statne ’s planned 420 kV line between Ofoten and Bals ord.
The Mirror Wall will not interfere with the vision of nature, but serves as a reflec on to the many who come here to hike. Mirror Wall is constructed of a simple steel la ce structure. The framework is covered with panels of reflec ng stainless steel with hidden fi ngs to give the desired reflec on of the landscape. The Mirror Wall is an innova ve and exci ng proposi on which is both integrated into and stands apart from the landscape.
32
“The Mirror Wall is new and different, yet in harmony with the environment and the scenic loca on.” The Mirror Wall is both new and different yet in harmony with the environment and the specific loca on. Old and new is synchronised in a single archaic form; the reflec ng square. For more informa on: www.statne .no
TIME FOR T
AND THE WINNER IS... Future, there was no site – how were we to consider the designs? Secondly, there was the implicit assertion that there was something ‘wrong’ with the existing generic design – the lattice pylon.
By Bill Taylor, Architect and Partner, Taylor Snell LLP
When I was asked to be the Architectural Assessor for the RIBA Pylon for the Future Competition, I paused for thought. Firstly, this was an unusual competition. Normally, teams are asked to put their minds to designing a building, or a piece of a city, or a bridge. There is nearly always a place where the project is to be located and which it will respond to. In Pylons for the
Actually, I quite like the ‘standard’ lattice design myself. In their purest form they are structurally efficient, calm and elegant – especially at dusk when the almost transparent openness of the lattice can appear like a fine tracery against a clear silver sky. The problems come with the grotesque mutations to their form that is often necessary at each change of direction of the conducting cables. Thirdly, was the winner we would chose ever to be built? Far too many architectural competitions are nothing more than client pipe dreams, the energies 34
and efforts of the teams being wasted on a project that never had a chance of being realised. Against these reservations was balanced the nagging question: is it possible to improve the technical performance and shortcomings of the existing design? With National Grid about to embark upon an enormous programme of new infrastructure investment in our country, in ever more demanding and sensitive locations, now was a good time to ask! More than any architectural competition, probably since the Scott Telephone Box, this was a chance for architects and engineers to consider the effect of their work on not just a single site, but on an entire nation’s landscape. No mean responsibility or task, the stakes were high – it was a question that needed to be answered.
Chris Huhne, Secretary of State and Nick Winser from National Grid had both given their public backing to the project, their teams were in place and well organised and we were all set to go.
Chief executive of National Grid Steve Holiday presents the T-Pylon to Prince Philip at the Royal Academy of Engineering
I felt that if we could find a ‘worthy winner’, there was a strong chance that something could end up getting built and some answers might be found. The clients had anticipated the sensitivity of the subject well.
“It must be said that the competition attracted both enormous public interest and a level of response from the design professions like no other architectural competition that I can recall”.
Clearly this was a subject that was very close to the nations heart. As I soon discovered, an electricity pylon and the power lines it supports are highly technical pieces of engineering design. And whilst there might well be a ‘generic’ pylon type, there are almost countless variants upon this theme – the design must respond to changes in voltage, numbers of cables, alignment on plan and section, direction, above ground, below ground etc etc. It was really a ‘family’ of pylons that we were looking for – or rather, the design of a generic pylon type that could develop to become a coherent family. The competition was open to all. One of the main challenges of the competition therefore was to elicit creative and imaginative designs that were also technically feasible, or at least, could be made to be technically feasible. Most competitors interpreted the competition to be about ‘appear-
ance’ and aesthetics – which in part it was. However it became evident that the better entries had questioned the engineering principles and/or requirements as part of their design methodology. As we were looking to eventually choose a pylon with a view to getting it built, these were the ones that made the second stage. The second stage involved teams developing their concepts in discussion with National Grid and their engineering experts. New ideas and technologies were open to exploration, but so too were possibilities of new working practices from the NG engineering teams in response to these opportunities. This was a very exacting stage for the competitors. The technical limitations of some of the more compelling ideas soon came to the fore under closer and detailed scrutiny. What visually appeared a most graceful response to the typical condition, was in the next breath shown to be a fundamental limitation to the atypical. 36
As ever, some teams responded more positively to this process than others. Ultimately, the T-Pylon design from Bystrup emerged the clear winner. What set this proposal apart was its starting point. The radically innovative move here was the reassessment of the conductor/cable alignments, NOT the pylon shape – which was the result of this.
T-Pylon, The winning entry, November 2011
By arranging the cables in a prismatic configuration, the heights of the pylons could be reduced by nearly 40%, the landtake and footprint of the power lines reduced, the EMF radiation levels reduced, the steel tonnage probably contained to no more than the lattice pylon. And, like nearly all good engineering, it was a very elegant, calm and natural visual solution. It all seemed so obvious!
Cost was not really a criteria in the competition or the assessment. However, in T-Pylon, the generic approach is one that will hopefully prove to be inherently flexible and economic. In choosing T-Pylon, the panel felt that they had seen a concept that could develop into a family and that would be strong and robust enough to withstand the gruelling
37
technical and commercial pressures that National Grid would inevitably put it under in the development programme. Bystrup and National Grid have, I understand, been making great progress since the competition results were announced. A prototype is finished and a test line construction is in progress.
DEVELOPING THE T-PYLON
By Peter Botsoe, Pylon Development Manager, National Grid
National Grid was looking for a modern 21st century pylon design that meets the aesthetic requirements of today. We wanted an innovative design concept that could be made in reality. In the T-Pylon we believe we have found it. The T-Pylon is a structure with very few parts. We expect it to be constructed quickly and require
no maintenance. When I saw the design initially, I thought it would be quite a challenge to develop, particularly the composite insulator units. Despite being referred to as the ‘diamond earrings’, they are actually quite large structures, 13 meters by 8 meters. At first sight the design appears simple, especially considering its function; however there were many challenges to address. When you look at the monopole design such as the T- Pylon, the first thing that strikes you is that all of the conductors are held from one attachment point; this is just unheard of. Traditionally, the structure has three separate arms each holding an individual conductor. We have had to look at this particular connection point and ensure its robustness and fatigue resistance.
38
Complex analysis and physical loading tests have been carried out to simulate climatic conditions such as high winds and ice loading. We have also investigated how the structure performs dynamically under simulated vibrations. We are very confident that the T-Pylon will be fit for its purpose and will be as safe as an existing lattice structure. Working with Bystrup in developing the T-Pylon from the initial concept, we have worked through a lot of difficult challenges quickly. Together, National Grid and Bystrup have scrutinised constructability and maintainability issues ensuring that all health and safety requirements are met.
In the European Grid Report, the new role of National Grid in energy policy is defined: During recent years, National Grid has perceived a change in its role within the bigger picture of energy policy – independent from specific projects. The company understands that explaining the context and consequences of political decisions is increasingly becoming more its task if it aims to succeed in achieving social acceptance of specific projects. National Grid reported that citizens are only willing to engage and potentially accept the consequences on a local level when they have a better understanding of the bigger picture. The communication of specific projects always starts with explaining the general energy policy. As an example, National Grid adds a short animation to its project websites, which explains where gas and electricity come from and how National Grid sources and delivers energy to homes around the country. http://renewables-grid.eu/uploads/media/RGI_ European_Grid_Report_final_01.pdf
T-PYLON
CONTEMPORARY AND SUSTAINABLE “To see T-Pylon becoming a reality just 20 months after winning the competition, is a fantastic achievement for BYSTRUP and National Grid”
Edward Davey Secretary of State for Energy and Climate Change, UK
The new design is a monopile with a T shaped cross-arm – hence the name T-Pylon.
The pylon is lower than a standard lattice tower, due to the innovative layout of the insulators and conductors arranged in a diamond earring shape.
stringing devices to mounting methods. Prototypes of the suspension and the tension pylons have been built; and mechanical and electrical testing has been conducted. A test line is planned for 2014. For more information: www.nationalgrid.com/uk
It meets the same safety clearances as the lattice tower but is 10 to 15 metres shorter the T-Pylon stands at about 35 metres.
The T-Pylon is a compact design. Strong, steady and at the same time delicate and optimistic.
The T-Pylon unites contemporary materials and aesthetics with mechanical strength and practicality.
It has the benefits of being shorter and lighter than the conventional lattice tower - a contemporary and sustainable design.
When developing the T-Pylon, all elements and procedures of the transmission system have been scrutinised and improved - from 40
Watch the film
OPTIMISING
TECHNICAL PERFORMANCE The design of an entirely new pylon provided an opportunity to optimise the operation of the grid. A fine example of this is the improvement made to the installation of the cables on the pylons. The new stringing tool is a single element which attaches directly to the yoke plate of the insulator assembly and requires no further support.
By Per Kristian Dahl & Friederike Faller Senior Development Designers, BYSTRUP.
The cable can be strung directly into place in a single procedure. The new stringing device replaces the conventional stringing block which requires lifting apparatus and often temporary superstructure to hold it in place while the cables are transferred from the block to their clamps.
Eliminating this stage of the stringing process simplifies the procedure. As a result, the time efficiency is increased and the cost of establishing new power lines is reduced. Our design approach does not just focus on the result, but embraces technical challenges in the process to develop better solutions. We have designed the construction tools and carefully considered the construction process in order to energise the pylons as efficiently as possible.
Generic stringing tool.
42
ACTING RESPONSIBLY Everybody talks about sustainability, as the increasing consumption could have severe consequences for the planet. Putting the adjective ‘sustainable’ in front of everything will not solve the problem. For many years, BYSTRUP has worked with sustainability - or responsible design as we like to call it - in order to understand its basic principles. The answer is a complex combinations of material characteristics, thorough knowledge and responsible recycling. To ensure a future which allows a high living standard without pollution and destruction of ecosystems, we must make sure that things move in the right direction.
Sustainable living must become a natural part of everyday life. This cannot be done through coercion, prohibitions or new laws, but rather by offering qualities that improve everyday life and provide people the courage to take responsibility for the future. By thinking globally and acting locally, it is possible to create a future worth looking forward to. This is one of the main reasons why we always include sustainability in our projects: from solar heating of large exhibition halls to natural ventilated office buildings and the design and planning of new overhead transmission lines.
44
Founder and partner Erik Bystrup speaks at the 2013 International Symposium for Responsible Architecture in Ferrara, Italy. Panel discussion on sustainable architecture with Thomas Herzog, Harald Stuehlinger, Sir Michael Hopkins, Peter Rich, Rahul Mehrotra, and Glenn Murcutt, who also were guest speakers in Ferrara.
We look for products that optimise lifespan and minimise surface treatments to ensure that little maintenance is needed. A lifespan of up to 100 years with low maintenance can be achieved by choosing the right materials for the design. We are developing solutions, based on recyclable materials.
We see it as an important parameter for our common future that responsible accountability becomes an important part of our everyday life. Therefore, BYSTRUP participates in global collaborations and green organisations.
Our goal is that soon sustainability is no longer something you talk about - it’s something you do!
COMPOSITE PYLON SIGNIFICANTLY SMALLER
After years of developing power pylons, it has become clear that we need a new mindset and a new approach to the materials used in the industry.
Erik Bystrup, Founder and Partner, BYSTRUP
“It is important to understand that when designing the future power lines, the focus should not be on the individual bits and pieces, but on all aspects as a whole - economical, technical, aesthetic, environmental�.
We have developed a new pylon that defines a new era of the transmission line industry: A pylon that is rising from the ground as a unibody insulator with two cross-arms, each carrying 400 kV, kept up by a shaft connected to a monopile that is rammed down to calculated depth. The pylon can be assembled on site and erected in one single day. The Composite Pylon is made from materials used for standard composite insulators.
46
It is constructed of glass fibres and polymers and covered by silicone sheds. The pylon is in fact an insulator in itself. By optimising the length of the span in relation to the height of the pylon, we are able to reduce the distances between the conductors significantly.
As the illustration to the right shows, this conceptual design is significantly smaller than the lattice tower and economically very competitive.
Sebastian Dollerup, Head of Power Lines, Energinet.dk
By combining the advantages of new technologies and new materials, we are able to create a structure which is easy to understand and appreciate.
“The Composite Pylon completely rethinks the design of overhead lines, making it the power pylon for the future�.
48
The Composite Pylon: • • • • • •
L13 Pylon
T Pylon Composite Pylon
Compact design Simple and fast foundation Erected in a day Made from standard composite materials A unibody insulator Cost competitive
BEFORE AND AFTER
IMPROVING AN EXISTING LINE The lattice tower is the most commonly used transmission tower. The illustration shows a typical situation of two adjacent lines, where a twin line has been added to an existing line in order to meet rising demands. Today, we know for a fact that this is twice as many lines as needed. When a lattice tower line is close to the end of its lifespan, a replacement is required. The Composite Pylon is roughly half the size of the lattice tower and is able to carry 2x400 kV in a single line. One Composite Line replaces two conventional lines.
50
Existing line Two lines each carrying 1x400 kV Proposed improvement One line carrying 2x400 kV
LIFE AT BYSTRUP
Q&A: SIMON HARKER, MAA MEng It is fulfilling to see that our designs will innovate and make improvements upon existing systems.”
Simon Harker, BYSTRUP
What is it like working at BYSTRUP? ”It is an exciting place to be. We are making big steps in a field of design which is relatively unexplored. This gives us the opportunity to explore modern material and technological advances. We have a core of experience and knowledge to expand upon as we develop new design solutions.
What characterises BYSTRUP? ”It is rare to find a group of designers and engineers working together on a range of interesting projects whilst having a concentrated focus at the forefront of a specialisation such as pylon design. I had not encountered such a strong design and development approach before I moved here from England.” What is the most exciting part of your job? ”Seeing our designs realised as full scale prototypes.”
52
In your opinion, why is the design and positioning of power pylons so important? ”In order to ensure that new transmission lines appear positive on our landscapes, power pylons should be as uniform and as low as possible. The design of pylons is also about the deviation situation, where transmission lines change direction. This typically creates scenic turmoil! The alignment of the pylons is at least as important as having a product that works. These two things combined determine whether the transmission line is successful or not.”
How did BYSTRUP end up designing power pylons? “We have always ventured into projects, where we felt something could be improved through development and design.
Power pylons seemed like a natural part of our field: an infrastructural element with an impact on the landscape, which had not evolved for more than 50 years.
53
In 2001, we won a design competition in Denmark, which resulted in our first power pylon. Since then, many pylons have followed.�
BYSTRUP Vermundsgade 40 DK 2100 Copenhagen + 45 39 27 00 85 www.bystrup.dk
54
WWW.BYSTRUP.DK