Windpower Engineering & Development - JUNE 2017

TURBINE FIRES AND HOW TO PREVENT THEM / page 38 June 2017

www.windpowerengineering.com

The technical resource for wind profitability

SUITING UP FOR

SAFETY It takes more than a harness

Microgrid system to stabilize grid power in Alaska

W

ainzdp teowe cbr Ex oplo 2 tin017 gb.oot coh# m27

60

PAGE 31

WPE JUNE 2017_Cover_Vs3.indd 1

6/9/17 9:12 AM

EXPERIMENTS BELONG IN A LAB

NOT IN YOUR TURBINE.

The right oil shouldn’t be a guessing game.

Maximize your ROI with AMSOIL PTN 320, one oil, no guessing.

DEVOTED TO PROTECTION

SEE US AT BOOTH #2848 AMSOIL_4-17.indd 29

™

• •

Specifically formulated to meet the needs of wind turbines, addressing the areas where others failed.

OEM approved, customer verified for over 8 years with an industry leading warranty.

NO ADDITIONAL TOP TREATS NEEDED FIND OUT MORE AT

AMSOILWIND.COM

6/8/17 10:12 AM

HERE’S WHAT I THINK

Editorial Director | Windpower Engineering & Development | pdvorak@wtwhmedia.com

Consider these costs as you amble through life

M

A|S|B|P|E Fostering B2B editorial excellence

American Society of Business Publication Editors

2017 National

DESIGN Gold

Revenue of $3 million or under

A|S|B|P|E

ost people don’t buy so much as bubble gum without asking, “How much does it cost?” So for your amusement I have assembled a list of costs arranged in an order that you may find entertaining. Hopefully, you’ll find the apples-to-oranges juxtapositions equally interesting. A tip of the hat for the idea goes to former collague and mentor the late Ronald Khol.

Readers are invited to make what they will of the figures assembled here. These bits and pieces have been collected in a file for over a year and I have not kept track of their original source, although YouTube provided useful historical perspectives. What would you add?

Talley of the amount invested in U.S. wind projects over last 10 years: $128 billion. Next generation wind technology R&D by 2026: $36.9 billion. Expected worth of steam-turbine market by 2020: $19.3 billion. Global airport security market by 2023: $12.72 billion. Market worth for wind-turbine composites by 2021: $12.17 billion.

IRS evaluation of Michael Jackson’s estate: $434 million. Estimated cost to decommission a nuclear reactor in France: $322 million/GW or $322,000/MW. Cost for five wind turbines and their installation at Block Island: >$250 million. Stock bonus to Glenn Kellow, coal exec who led Peabody Energy (a coal company) through bankruptcy: $15 million.

Fostering B2B editorial excellence

American Society of Business Publication Editors

2017 Regional

DESIGN Gold

Revenue of $3 million or under

JUNE 2017

Editorial_6-17_Vs3.indd 1

Offshore wind rights for Kitty Hawk, NC: $9 million.

Dynamic positioning device for a wind-turbine barge: $7.7 million. A prize fund for African renewable-energy projects: $7 million. Estimated cost to launch one offshore turbine with novel construction barge: $6.9 million. Amtrack locomotive: $6.5 million. NY fund for

clean-energy education: $5.5 million. One 1.5 MW GE 1.5sle: $3.37 million. Rule-of-thumb costs for land-based turbine: $2 million/MW. Amtrack passenger car: $400,000. Gearbox replacement and crane callout: $244,000. One WWII B17 in 1945: $238,329. A refurbished 2 MW, 50-Hz generator: $78,846. Mikado steam locomotive (#4501) in 1905 : $23,182.

Generator bearing change out: $6,000. Research report on wind and solar markets: $4,500. Lost production per day from turbine downtime: $2,120.

Estimated value Michael Jackson’s estate by its estate: $2,105. 1-hp Grundfos 240V electric motor: $1,400.

Hatsan Nova 0.22 air rifle: $749. Apple iPhone 6: $549. Report on storage and smart grid: $299.

Estimated kilowatt-hour cost for a pack of Tesla batteries by 2020: $217. Blade-bearing gasket for Gamesa G47 turbine: $176. Month of fitness classes in Ohio: $129. Shell Rhodina grease, box of 12, 400g tubes: $136. Monster testosterone booster: $79.99 One barrel WTI crude oil, 6/6: $47.22. Power/ MWh levelized in 2015: $41.10. Shampoo, blowdry, and style: $30. Wind power PPA per MWh, from interior U.S. in 2015: $26.43. Generator brushes: $17. A 2008 prediction for one gallon of gasoline in 2015: $9.15. Small wind turbine, per watt: $3 to $6. One-million BTUs of natural gas on 6/6: $3.02. Industrial electric prices in Germany, per kwh: $0.16. One dozen nonorganic eggs: $0.99. W

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT

1

6/8/17 11:09 AM

Follow the whole team on twitter @Windpower_Eng

E D I T O R I A L EDITORIAL

DIGITAL MEDIA / MARKETING

VIDEO SERVICES

Editorial Director Paul Dvorak pdvorak@wtwhmedia.com @windpower_eng

Web Development Manager B. David Miyares dmiyares@wtwhmedia.com @wtwh_webdave

Videographer Manager John Hansel jhansel@wtwhmedia.com @wtwh_jhansel

Senior Editor Michelle Froese mfroese@wtwhmedia.com @WPE_Michelle

Digital Media Manager Patrick Curran pcurran@wtwhmedia.com @wtwhseopatrick

Videographer Bradley Voyten bvoyten@wtwhmedia.com

Associate Publisher Courtney Seel cseel@wtwhmedia.com 440.523.1685 @wtwh_CSeel

DESIGN & PRODUCTION SERVICES VP of Creative Services Mark Rook mrook@wtwhmedia.com @wtwh_graphics Art Director Matthew Claney mclaney@wtwhmedia.com @wtwh_designer Graphic Designer Allison Washko awashko@wtwhmedia.com @wtwh_allison

Traffic Manager Mary Heideloff mheideloff@wtwhmedia.com Production Associate Tracy Powers tpowers@wtwhmedia.com

B E C O M E

Engaged

S T A F F

Senior Web Developer Patrick Amigo pamigo@wtwhmedia.com @amigo_patrick Web Production Associate Skylar Aubuchon saubuchon@wtwhmedia.com @skylar_aubuchon Web Production & Reporting Associate Jennifer Calhoon jcalhoon@wtwhmedia.com @wtwh_jennifer

Videographer Derek Little dlittle@wtwhmedia.com @wtwh_derek

FINANCE Controller Brian Korsberg bkorsberg@wtwhmedia.com Accounts Receivable Specialist Jamila Milton jmilton@wtwhmedia.com

Digital Marketing Director Virginia Goulding vgoulding@wtwhmedia.com @wtwh_virginia Manager Webinars Stacy Combest scombest@wtwhmedia.com @wtwh_stacy

2014 Winner

Marketing Manager, Social Media & Events Jennifer Kolasky jkolasky@wtwhmedia.com @wtwh_jen

2011, 2012, 2013, 2014, 2015, 2016

2013 - 2016

Director, Audience Development Bruce Sprague bsprague@wtwhmedia.com

2014 - 2016

WTWH Media, LLC 6555 Carnegie Avenue, Suite 300, Cleveland, OH 44103 Ph: 888.543.2447 • Fax: 888.543.2447 WINDPOWER ENGINEERING & DEVELOPMENT does not pass judgment on subjects of controversy nor enter into disputes with or between any individuals or organizations.

WINDPOWER ENGINEERING & DEVELOPMENT is also an independent forum for the expression of opinions relevant to industry issues. Letters to the editor and by-lined articles express the views of the author and not necessarily of the publisher or publication. Every effort is made to provide accurate information. However, the publisher assumes no responsibility for accuracy of submitted advertising and editorial information. Non-commissioned articles and news releases cannot be acknowledged. Unsolicited materials cannot be returned nor will this organization assume responsibility for their care.

WINDPOWER ENGINEERING & DEVELOPMENT does not endorse any products, programs, or services of advertisers or editorial contributors. Copyright© 2016 by WTWH Media, LLC. No part of this publication may be reproduced in any form or by any means, electronic or mechanical, or by recording, or by any information storage or retrieval systems, without written permission from the publisher.

VISIT US | LIKE US | TWEET US | CONNECT WITH US

SUBSCRIPTION RATES: Free and controlled circulation to qualified subscribers. Non-qualified persons may subscribe at the following rates: U.S. and possessions, 1 year: $125; 2 years: $200; 3 years $275; Canadian and foreign, 1 year: $195; only U.S. funds are accepted. Single copies $15. Subscriptions are prepaid by check or money orders only.

SUBSCRIBER SERVICES: To order a subscription or change your address, please visit our web site at www.windpowerengineering.com WINDPOWER ENGINEERING & DEVELOPMENT (ISSN 2163-0593) is published six times per year in February, April, June, August, October and a special issue in December by WTWH Media, LLC, 6555 Carnegie Avenue, Suite 300, Cleveland, OH 44103. Periodicals postage paid at Cleveland, OH and additional mailing offices.

POSTMASTER: Send address changes to: Windpower Engineering & Development, 6555 Carnegie Avenue, Suite 300, Cleveland, Ohio 44103

2

Staff page_WIND_6-17_Vs1.indd 2

WINDPOWER ENGINEERING & DEVELOPMENT

www.windpowerengineering.com

6/8/17 12:37 PM

Pheonix Contact_6-17.indd 29 PxC17-0877_QUINT4 Wind_9x10.875.indd 1

6/8/17 10:18 AM 5/17/2017 2:13:34 PM

www.windpowerengineering.com

JUNE 2017 • vol 9 no 3

CONTENTS

D E PA R T M E N T S 01

Editorial: Write your own editorial

34 Safety: Safety tips for every wind tech

06

Windwatch: Inspecting a turning rotor,

38 Fire prevention: Turbine fires and how to prevent them

Gearboxes get upgrades, Wear protection for drip-loop cables, An unusual vortex generator, and meet the offshore vessels and cranes

40 Condition monitoring: Giving generators proper attention

24

Reliability: Preventing power electronics from

42 Software: A better way to make use of drone blade

28

Bolting: 7 electric developments that make tools smarter

44 Turbine of the month: Exploring the possibilities of

Energy storage: System to stabilize grid power

64 Downwind: The world’s first wind turbines that boast of

31

overheating

in Alaska

inspections

four rotor turbines

built-in hydroelectric capability

F E AT U R E S

46 Why lubricant formulation & oil

analysis matters for wind-turbine gearboxes

For maximum performance, a gearbox lubricant must be correctly specified for a wind-turbine’s operating conditions and carefully monitored. A poor lube choice or ignoring oil cleanliness means a turbine’s gearbox will fail to function properly or with much longevity.

34 ON THE COVER

52 New technology looks out for eagles and bats near wind farms

Previous attempts to guard avian wildlife from wind turbines have involved project cancellations or observers with binoculars scanning the sky ready to report invaders. Good news: This next generation of equipment aimed at eagles and bats is more vigilant, reliable, and effective.

The wind technician uses hydraulic equipment and proper technique to check bolt tightness.

Photo courtesy of Larry Smith Ecotech Institute | ecotechinstitute.com

58 Identifying wind industry trends help predict its future

Each year the Windpower Engineering & Development staff and its research department identifies the more significant trends that drive the wind industry. The effort is to answer the frequently asked big question: Where do we go from here?

4

WINDPOWER ENGINEERING & DEVELOPMENT

Table of Contents_6-17_Vs4.indd 4

www.windpowerengineering.com

JUNE 2017

6/8/17 3:57 PM

CONTRIB U TO R S

MOSESON

MAROTTA

CLARK

DAVID CLARK, President of CMS Wind, has been involved in gigawatts of end-ofwarranty inspections. He also has experience monitoring and analyzing wind turbines ranging from 100 kW up to megawatt-classes from multiple manufacturers on towers installed globally. Clark has also authored the AWEA best practices for blade condition monitoring, contributed to several industry reports, and was involved with the EPRI report on wind-turbine condition monitoring in 2005. Since 1999 he has presented several times for American Wind Energy Association (AWEA), National Renewable Energy Labs (NREL), several wind operations and maintenance conferences domestically. Reach him at info@cmswind.com

SHROYER

ROBERT J. MAROTTA is the Product Sales Manager for Parker Hannifin’s Accumulator Cooler Division. Parker’s engineers’ design custom, precision-engineered solutions that help wind-power plants generate energy more efficiently, while improving uptime and reliability.

JUDAH MOSESON has over 30 years of experience in electrical power generation.

He has been active in the renewable energy sector for the past 12 years. Moseson has held leadership positions in marketing, engineering, construction, and operations and is currently the VP of Business Development for Cooke Power Services.

CHRIS SHROYER, President of EdgeData, joined the company as a member of the entrepreneurial team of founders in 2015. Now he leads the execution of the business plan with his management team counter-parts. His areas of focus include client relationships, strategic partnerships, new-market development, and revenue growth for the organization. Prior to his work at EdgeData, Shroyer was VP of Sales and Marketing at Involta, an award-winning data center and technology services company that spent multiple years on the Inc. 5000 List of America’s Fastest-Growing Companies, reaching #40 at its peak of growth.

Subscribe to our

E-NEWSLETTER DON’T MISS A THING, SIGN UP TODAY!

Stay up-to-date between issues of Windpower Engineering & Development.

Get breaking news, product innovation, technical developments and resources right to your inbox.

Visit our site online to sign up! www.windpowerengineering.com

Contributors 6-17_Vs4.indd 5

6/8/17 12:33 PM

SIZING SIZING UP UP NEW NEW OFFSHORE OFFSHORE VESSELS, VESSELS, CRANES CRANES & & SHUTTLES SHUTTLES SOME CALL IT THE “HIGH WIND” OR “OFFSHORE PARADOX.” The further offshore a wind project, the more challenging it is to install safely and cost-effectively. But despite the difficulty, a few global wind developers have their sights set on deeper waters and higher winds, which hold promise of greater power generation.

This means offshore construction typically happens in rougher seas and harsher conditions. It also means equipment, such as cranes and jack-up vessels, must have the capacity to reliably lift and hold taller towers, longer blades, and heavier turbines, regardless of wind or current.

Undeterred, equipment manufacturers in the UK have been working diligently to meet offshore demands. Their labor has resulted in a new, heavy-lift jack-up vessel, a foldable offshore crane, and a wind-turbine shuttle that also serves as an installation vessel.

Meet the “SOUL” SOUL is a jack-up vessel and crane in one that's engineered to support the installation of today’s 6 to 8-MW turbines, as well as the next-generation of 10 to 15-MW units. According to its designers, Norway shipbuilding companies Ulstein and SeaOwl, the SOUL weighs about 10% less than conventional jack-up designs, thanks to its unique cruciform layout.

Scaling-up to meet the requirements of turbines that are only a couple more megawatts in size seems a simple enough — just build a bigger crane and vessel. However, the disproportionate weight increase compared to the necessary gain in variable deck load poses a design challenge for jack-up vessels.

“We noticed this created uncertainty with wind-farm operators and contractors in terms of how to install larger, future generations of offshore wind turbines because floating vessels are simply not a viable alternative in harsh offshore conditions,” says Erik Snijders, Founder and Managing Director at SeaOwls. “So we went back to a jack-up design and a square platform with the legs spaced out as much as possible.”

6

WINDPOWER ENGINEERING & DEVELOPMENT

Wind Watch_6-17_Vs6.indd 6

www.windpowerengineering.com

JUNE 2017

6/8/17 11:24 AM

Huisman recently designed and built a 1,500-metric-ton Leg Encircling Crane just for offshore wind projects. It is currently the largest LEC in the world.

JUNE 2017

Wind Watch_6-17_Vs6.indd 7

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT  

7

6/8/17 11:24 AM

W I N D W A T C H

The SOUL, heavy-lift jack-up vessel has a cruciform structural lay-out that is more than 10% lighter than conventional designs. The vessel will come in a number of sizes and provide transport of up to six 10 to 15-MW wind turbines. All load and install operations can be performed without the need of ballast water.

A leg up — and around Although the SOUL is an innovative development, Ulstein and SeaOwl say they have so far only shown a preview of the jack-up vessel to a select group of industry professionals.

For jack-up vessels that require a separate crane, and one capable of withstanding harsh offshore conditions, Huisman recently designed and built a 1,500 mt (1 metric ton = 1,000 kg) Leg Encircling Crane (LEC) just for wind projects. It is currently the largest LEC in the world.

As its name suggests, the crane is built around a jack-up leg and, when required, the boom can be stored around another leg to save valuable deck space. The LEC also has a small tail swing to allow for optimal use of free deck space. For example, the 1,500 mt LEC has a required leg opening of 11m and a tail swing of only 14.5m at operator cabin level. The operator cabin mounts to the side of the crane.

So that the crane weight is equal or less than its lifting capacity, Huisman uses a design philosophy that has proven its value in the offshore oil and gas industry.

David Roodenburg, Director Strategy and Business Development at Husiman, explains: “By using highgrade steel and an intelligent design,

the need of ballast water, which is someSnijders says that rotating the SOUL’s times added to the cargo holds of vessels platform by 45 degrees provided a natural to increase vessel stability at sea. bow shape to its design, with two large legs.

“It’s interesting how a seemingly A crane is then positioned on the vessel’s simple twist in the design let us make such center line. improvements in operational aspects,” “With the main crane built around a adds Lambregts. “We look forward to seestern leg, it creates more of an optimal main ing SOUL at work offshore.” deck reach and better over-the-side lifting capabilities,” explains Bram Lambregts, Deputy Managing Director at Ulstein Design & Solutions BV. “And because the hull now houses much larger To improve the efficiency of offshore wind-turbine leg footings, bearing installations and allow for increasing economies of scale, pressures on the seabed the offshore crane company Huisman, has developed are significantly rethe Wind Turbine Shuttle (WTS). This is a fast-sailing duced.” He says that the vessel that can carry and install two fully assembled wind wake of the legs’ pads turbines. The WTS can hit speeds of 14 knots and cover (or spud cans) means about 150 miles in just over 10 hours. there is no interference with the inflow to the According to Husiman, WTS offers 80% workability in annual propulsion thrusters.

North Sea conditions, which is quite good. By combining The new SOUL low vessel motions, compensating systems, and an accurate series will come in sevdynamic positioning system, wind turbines are kept eral sizes for the efficient stationary in relation to a fixed foundation during install. transport of up to six 10 to 15-MW wind turbines.

Currently, the shuttle can transport out turbines with Lambregts maintains all ratings of up to about 5 MW, and carry ailing turbines or loading and install operations can occur without components back to shore for repair.

LEAVING CRANES BEHIND

8

WINDPOWER ENGINEERING & DEVELOPMENT

Wind Watch_6-17_Vs6.indd 8

www.windpowerengineering.com

JUNE 2017

6/8/17 11:24 AM

W I N D W A T C H

components to around 160m above deck level from a vessel with a jack-up height of 0 to 70m,” he says.

Also slightly tilting the hinge in the boom adds extra boom clearance to the crane. “This simplifies lifting of large loads and reduces the required boom length to reach above the middle of a nacelle,” says Roodenburg.

Furthermore, the crane can be retrofitted on existing jack-ups, which is particularly useful for operators in need of more hook height to answer the growing demands of the offshore wind industry.” W

a low construction weight is achieved that provides for an increased remaining payload on the jack-up vessel compared to conventional leg encircling cranes.”

The Leg Encircling Crane comprises of a steel A-frame, bolted on a pedestal via the slew bearing, a lattice type boom, and various hoist tackles to control the boom and the lower blocks.

Roodenburg says Huisman is one of only a few companies that has successfully constructed and employed large-diameter slew bearings. “By applying Huisman’s segmented slew bearing, the overturning moment is transferred into the vessel structure in a highly structured way.”

He adds that the design reduces the amount of steel needed yet safely transfers forces into the vessel structure. “The crane’s slew bearing, built from multiple segments, allows for easy inspection and maintenance."

Furthermore, a slew bearing requires no kingpin to transfer the crane’s horizontal loads. “Plus, all of the LEC’s main equipment, except for winches, are located inside a closed housing to protect it from the harsh marine environment,” Roodenburg says.

The enclosed construction also protects the internal rollers and raceways.

The Foldable Offshore Crane combines strong and sufficient lifting capacity with a foldable boom that results in less required deck space and a low own weight of the crane.

Offshore O&M The crane that works well in offshore windfarm construction may prove unsuitable for turbine maintenance. To better meet the needs of the offshore O&M industry, Huisman has also developed a lightweight crane specifically for the maintenance of offshore turbines.

The Foldable Offshore Crane sports a foldable boom, which results in a small footprint in its storage position and a simple crane to transport. “The folding mechanism leads to a much lighter unit compared to conventional cranes, which simplifies inspection and maintenance because the lifting hooks are safely stored inboard,” explains Roodenburg.

He says the ideal maintenance jack-up vessel has a small deck, is cost-effective, quick to mobilize, and can lift up to 600 mt to a height of over 160m. “So the Foldable Offshore Crane is well suited for work of this capacity on jack-ups because it is capable of exchanging wind-turbine WINDPOWER ENGINEERING & DEVELOPMENT

Wind Watch_6-17_Vs6.indd 9

9

6/8/17 11:24 AM

W I N D W A T C H

Infrared shows and ultrasonics hears blade flaws on a working turbine THERE MAY BE LESS REASON NOW to shut down a producing turbine to inspect its blades say developers and users of the SABRE Blade Inspection System with its new infrared and acoustic sensors. At the recent Wind Energy Update O&M Dallas Conference, Brandon Fitchett, Senor Technical Lead for renewable generation at EPRI commented on the multi-year project to validate the system on blades at EPRI member wind farms. Electric Power Research Institute is an independent non-profit conducting research guided by utility advisors. Dennis Buda with Detroit Edison, one of the advisors, added his experience with the promising technology developed by Digital Wind Systems Inc. (DWS) Infra-red Inspection "We have been testing ground-based equipment and processes with the potential for increasing the frequency and reducing the cost and risk from up-tower blade inspections," said Fitchett. The SABRE IR camera from DWS can find heat from stress concentrations caused by structural anomalies inside the blade. "So far, we have validated that infrared thermal imaging of this type is capable of detecting structural flaws and surface defects even when applied from a ground based vantage point," he said.

EPRI and DWS worked with Sandia National Lab and NREL for preliminary evaluations detecting fiber waves in composites with the infra-red technology. "Fiber waves − manufacturing flaws − are a major cause of blade failures. Such flaws create higher stresses and friction which cause local heating. The infrared sensors are calibrated tightly enough to detect a small fraction of a degree Celsius change, which has proven sufficient to highlight areas with structural defects," he added.

10

WINDPOWER ENGINEERING & DEVELOPMENT

Wind Watch_6-17_Vs6.indd 10

Acoustics A wide-band acoustic sensor provides other measurement possibilities. John Newman, president of Digital Wind Systems, and his team have developed an acoustic sensor that does not require shutting down the turbine, a big benefit for this technology. It can be used while the turbine is running and from the ground.

Normally, a rotating blade produces a white noise, a broad frequency spectrum throughout its time sample. "Because the air inside each blade is compressed towards the tips during rotation, blades with lightning strike holes, shell splits, or damage allow the air to escape producing sonic or ultrasonic whistles, like a tea kettle. While whistles are often heard in a wind farm, SABRE can now analyze these sounds and calculate the location on the blade, often matching the IR or high-speed photography indications. Because the

blades are rotating, the sound is Doppler shifted as the blade passes overhead. The whistling blades generate the frequency difference from the maximum to the minimum. This can be calculated as a Doppler shift in frequency which allows estimating how far out on the blade span the noise is coming from. It takes about one rotation of the rotor, five seconds, to pick out all the lightning strike holes, splits, and know where they are.," said Newman.

The SABRE equipment mounts onto an SUV that can be driven right to a turbine, stopping at inspection locations near the tower and getting data on all three blades in about 15 minutes.

Newman adds that SABRE testing includes supplemental drone inspections for any surface damage component to the indications detected. The technology’s big plus is knowing where to put further emphasis with any up tower inspections and repairs.

The top photo shows the time-spectrograph of sound from the blades on a 10-year old turbine, with defects on all three blades. The sounds are Doppler shifts and the frequency measured. The rotational speed allows calculating the location of the sound source. A sound coming from a lightning receptor usually indicates damage. Holes, splits, and leading edge erosional all have typical signatures.

www.windpowerengineering.com

JUNE 2017

6/8/17 11:24 AM

THE BEST OPTION IS HAVING ONE CastrolÂŽ is the only lubricant supplier that offers fit for purpose technology options. We utilize multiple product-based solutions that can align with your O&M strategy and deliver continuity within your fleet. Our expert engineering services can provide insights to help you obtain the maximum value from your lubricants and your turbines.

Ask us what options Castrol has for you.

Learn more at AWEA Windpower, Booth 2220.

Castrol.com/windenergy or 1-877-641-1600

BOOTH #2220

Š 2017 BP Lubricants USA Inc.

Castrol_4-17.indd 29

6/8/17 10:15 AM

W I N D W A T C H

"On one occasion, we found an indication of a large crack in a blade, but the OEM insisted the blade was fine. We suggested a closer look from the inside. Sure enough, they found a 1.4-m crack right where we said it was. It was a transverse crack, and its early repair saved the blade. That is the whole focus: find damage soon enough to repair the blade up tower at one tenth the cost of bringing the rotor down or replacing the blade. So there is a huge cost saving involved," he said.

Over 1,000 turbine blade sets have been inspected using the SABRE equipment mounted onto an SUV for fast mobility within a wind farm.

Typically, 15 blade sets can be inspected per day.

“So far, the system has been capable of spotting leading edge erosion, characterizing surface and subsurface damage of manufacturing defects, fatigue cracks, leading and trailing edge splits and pitch errors, and fiber waves. Those are probably one of the most important aspects because they are usually hidden and cause stress concentrations,” added Fitchett.

Limitations Limitation of the science come from the weather and climate. Infrared readings are made when the location is dry with moderate humidity (less than 80%), no fog, although tests have been conducted with good data during snow.

While the technology provides another tool for fast blade assessment, it is not yet a life predicting technology. "You cannot take the results and say how long 12

WINDPOWER ENGINEERING & DEVELOPMENT

Wind Watch_6-17_Vs6.indd 12

the blade will last," says Fitchett. It's also not yet able to determine the reduction in load capacity on the blades or life.

Although major defects show up immediately during the measurements, a manual detailed analysis is still required," he adds.

There is an occasional false positive, added Buda, meaning the acoustic sensor detects no structural problems but the blade still fails. In some cases, it is due to the turbulent flow shedding off the leading edge which obscures the structure on the spar caps.

Newman says new SABRE IR techniques would eliminate the problems of obscured defect thermal emissions.

In the field With John Newman's technology and EPRI assisting, DTE's Buda says his team is able to take much of the human element out of blade inspections and start looking at a fact based, real time inspections with a turbine running.

Buda says he uses drones on follow-up inspections but they do not give the data or pictures possible from the new technology. "What I really like about SABRE is that the turbine continues to run," he said.

The latest developments mount the IR camera and microphone atop a van that can be driven right to a turbine, stop 100 yards from it, and get data on all three blades in about 20 minutes. "On occasion, we will shut down the turbine and find that with 100% assurance, each blade has been categorized and identified with its issues. After that, it's on to the next turbine,” said Buda.

“Despite weather limitations, we found interesting defects during November 2014, such as leading edge erosion and some cracks and splits. Our target blades are susceptible to lightning strikes.

So we were able to identify blade dents, the lightning damage.

Repairs followed

www.windpowerengineering.com

in the Spring," added Buda.

In addition, he and Newman are building a database from previous inspections. “Inspections to new glass blades let us capture a couple of month data will let us see how they are performing after later inspections,” he said.

“Our goal is to develop the sensor technology, IP, and the test procedures for using it. DWS manufactures its own IR camera and acoustic sensors. We have tested every available commercial IR camera and you cannot use just any one and expect to find these types of defects,” said Newman. As with any nondestructive testing technology, training and strict use of procedures is critical. However, the sensors have been honed on over 1,000 turbines.

Detected damage is not absolutely quantifiable. “But it does make it possible to determine which blades to prioritize for later inspection or maintenance. Digital Wind Systems' database of results, realworld inspections, and occasional destructive inspections will allow a kind of calibration to actual damage,” said Fitchett.

For instance, SABRE easily identifies lightning strikes on tips. As soon as the crews get up there and start peeling back the gel coat and lightning cables, they see what has to be done. “We still need technicians to get up there to inspect, grind, and repair the blade,” he said. W The lower photo, an IR image of most of the low pressure side of a 48-m blade, shows (arrow) a 1.4m transvers crack at 10m from the root end. Just below is a close up of the crack, confirmed by internal blade inspection and subsequently repaired.

JUNE 2017

6/8/17 11:26 AM

W I N D W A T C H

Moventas ExtraLife gearbox will provide a four-fold overall life improvement according to computational testing by Sentient Science.

Short gearbox life now steadily lengthening as technology matures WIND-TURBINE GEARBOXES HAVE A WELL-DESERVED BAD REPUTATION for their short working lives. Not long ago, a two or three-year life was about normal.

Things are looking up, however. Two companies recently announced improvements to gearboxes that stretch their

working life to much longer periods. First, Moventas took the wraps off its Extra Life 1.5-MW gearbox last year and more recently, produced simulations by Sentient Science that point to a four-fold improvement in life. Then at the Wind Energy Update O&M Dallas conference, Gearbox

Simulation by Sentient Science show that the planet bearing will have better load carrying capacity versus conventional bearings due to lower contact stress The results also showed an 8% reduction in contact stresses.

JUNE 2017

Wind Watch_6-17_Vs6.indd 13

Express unveiled an upgraded version of its proprietary gearbox, Revolution 2.0.

Moventas says that premature failures in the GE 1.5-MW gearboxes have led to unexpected downtime and increased costs. Moventas developed upgrades for the gearboxes, now called Extra Life, that can reduce premature failures on all types of gearboxs. To qualify its modifications, the company enlisted Sentient Science to validate the technology and life-extension claims, and quantify the improvements in performance, durability, and reliability.

Computational testing shows a four-fold overall gearbox life improvement because of improvements made to the case-carburized ring gear, integrated planet-gear bearings, high-speed-stage bearings, tooth surface roughness, and material upgrades in bearings and gears.

Sentient Science used its DigitalClone, a material science-based program that predicts the earliest time when cracks initiate in the microstructure of rotating gearbox components. The key analysis factors used in DigitalClone computational modeling included material quality, surface roughness, and stresses based on a full gearbox model subjected to real turbine operating conditions. These are not explicitly accounted in industry standards.

Take the case-carburized ring gear, for instance. The method is used instead of another, such as case hardening. To demonstrate improved durability, simula-

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT  

13

6/8/17 11:26 AM

W I N D W A T C H

Gearbox Express says its Revolution 2.0 is available 1.0 to 2.3 MW across several platforms that the company supports, such as MHI 1000A, GE 1.5 S, Sle, Xle, 1.X, Vesta V80 and V82, and the Siemens 2.3. About 20 so far are in the field.

tions considered case-carburized microstructure, geometry, operating conditions, lubricant properties, surface finish, and residual stresses. More than 1,000 contact and bending simulations were conducted in DigitalClone software. The results demonstrated an improved L10 life from seven to 20 years, mainly due to better surface finish and material quality without detrimental defects or inclusions.

Also, a two-row arrangement of cylindrical-roller bearings is used in each planet of the new gearbox, instead of a fourrow arrangement typical of conventional designs. About 2,000 fatigue-life simulations were conducted in DigitalClone to compare the two-bearing arrangement. The planet 14

WINDPOWER ENGINEERING & DEVELOPMENT

Wind Watch_6-17_Vs6.indd 14

bearing showed better load-carrying capacity compared to conventional bearings, thanks in part to an 8% reduction in contact stresses. Moventas says its planet bearings now offer superior fatigue life and attribute it to cleaner material quality and relatively lower contact stress.

And speaking of cleaner material, a white-etching-resistance steel is used in the Extra Life gearbox instead of a black-oxide

coating showed a 3% probability of failure in less than 20 years at the high-speed shaft and high-speed intermediate shaft positions due to non-metallic inclusions. DigitalClone verified the white-etching resistant bearing is superior to other bearing materials in these positions. Furthermore, Moventas can replace these bearings up-tower, which lowers O&M costs and downtime.

Moventas add that its Clean Steel tech has also been showing good result against IMS tooth fractures. The company reports no IMS tooth fractures with the upgraded material spec. In conventional steels, non-metallic inclusions can be as large as 100µm on the intermediatespeed pinion. Contact fatigue life simulations in DigitalClone showed that the enhanced material doubles the life

For more than three years, we have been researching why the planetary configurations in some gearboxes were not reaching half of their designed lifespan. or a conventional bearing material. DigitalClone also validated that the white-etching resistance bearing material was superior to the black-oxide coating against white etch cracking due to heat treatment and improved microstructure. The black-oxide

www.windpowerengineering.com

over the original design. Rolling contact fatigue simulations demonstrated that the sun pinion used in the new gearbox with an Ra (surface roughness) of 0.3 µm increases L10 fatigue life by a factor of 2.2, compared to the original Ra of 0.6 µm.

JUNE 2017

6/8/17 11:26 AM

W I N D W A T C H

The company adds that the Extra Life gearbox showed a lower cost of ownership compared to the legacy platform. Also, the units come with five-year warranties.

ExtraLife features can be applied to larger gearboxes as well says the company. One example is Siemens 2.3 MW platform where Moventas has upgraded the design by using own core tech such as case carburized ring gear and combined two row bearing on the planet gears.

The more recent introduction comes from Gearbox Express. “The wind industry has wrestled with gearbox failures since its inception,” said Gearbox Express CEO Bruce Neumiller at the conference. “That led us to create our company and meet these challenges head-on. We are succeeding.” The company unveiled its initial Revolution gearbox in 2013 to address frequently seen failure characteristics. Since then, the company has successfully installed more than 200 of the designs across the United States. Neumiller says all are running well with the oldest about five years old.

“For more than three years, we have has been researching why the planetary configurations in some gearboxes were not reaching half of their designed lifespan,” said Neumiller. “Those development efforts are now in the Revolution 2.0.”

He says the top features of the new gearbox include:

• A redesigned planetary gear and bearing interface in which the bearing outer races are machined into the gear. This reduces the number of components and opportunity for failure.

All planet gears in the Revolution 2.0 gearbox will have super finished gear teeth.

• Integral tapered rollers are used in lieu of cylindrical rollers. The tapers permit preloading, which increases system stiffness and improves load sharing. The bearings also reduce internal bearing stresses, improve life 170%, and reduce rim deflection by 460%, which reduces bending stress and the propensity to crack planet gears.

• The use of steel that is cleaner than ISO 6336-5 ME. Cleaner steel improves contact and bending-gear ratings, letting planet gears run with a higher safety factor and significantly reducing the risk of failing from material inclusions.

•

• In-house super finishing improves as-ground surface finishes by 50%, ensuring bearing life while improving the gear rating.

Gearboxes are now outfitted with a metallic wear debris monitor from Poseidon Systems, letting GBX remotely monitor and proactively address oil cleanliness issues. In addition, the gearbox is backed by a fiveyear warranty, which includes crane and labor expenses. W

The Revolution 2.0 uses integral tapered rollers instead of cylindrical rollers. The tapers permit preloading, which increases system stiffness and improves load sharing.

JUNE 2017

Wind Watch_6-17_Vs6.indd 15

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT

15

6/8/17 11:26 AM

W I N D W A T C H

Your wind turbine’s power and data cables may be wearing faster than you think What a mess. The drip loop has made about one nacelle revolution and the yaw motors will have no trouble twisting it once more. This turbine owner should expect major insulation wear and eventually, exposed conductors.

THE DRIP LOOP IS THE BUNDLE OF CABLES responsible for carrying all the power, data, signals, and communication for everything generated inside a nacelle.

The loop is needed to provide enough slack for the turbine to yaw into the wind.

While the cables in this loop meet wind industry standards, especially for The CAD model of one SOHL unit show several triangular openings for up to three power cables. Smaller data cables are secured in other glands.

16

WINDPOWER ENGINEERING & DEVELOPMENT

Wind Watch_6-17_Vs6.indd 16

with expert installation. The companies, torsion, oil resistances, and temperature, System One Services, Hydac, and Lapp current industry practice of tightly USA, collaborated on the design of the bundling them have serious impacts.

SOHL, a turnkey cable-management The biggest problem with closely system, able to address the issue of drip arranging cables in this manner is there loop cable tear can be as many as 16 tightly bundled Moorman, also the SOHL program together, twisting and rubbing against spokesman, describes the device as each other. This arrangement creates a multi-function, engineered cable excessive heat and wears down the gland and management system for drip jacket insulation, ultimately exposing loop applications. “But it’s really a disc, a cable conductor which can carry between 600 to 1,000V. This wear can Over the past 15 years, I have appear only a few months after operation visited many wind farms with trash but is often missed or containers filled with cables that over-looked during end-of-warranty have been cut out of the drip loop. inspections or when competing with other informally called the snowflake star clamp, major corrective action. It’s no surprise less than one meter in diameter with that the abrasion issue can eventually several modular clamps that each secures lead to turbine faults and downtime, one to three cables,” adds Moorman and in worst cases, serious injury to “Our team has worked side by side technicians. “Over the past 15 years, I with technicians up-tower trying to have visited many wind farms with trash resolve power cable issues whether it is containers filled with cables that have dangerously exposed conductors, knots been cut out of the drip loop,” says Jim in the conductor, abrasion damage, or Moorman, wind industry manager at jacket damage relating to poor cable Lapp USA, a global cable manufacturer. management,” he says.

Three wind-industry specialists have There are home grown solutions, recognized the problem and joined but they often just exacerbated the forces to deliver a device that solves problem. “For instance, 12 to 15 zip the premature cable wear issue along

www.windpowerengineering.com

JUNE 2017

6/8/17 11:26 AM

High Speed Shaft Solutions

Zero-Max Wind Ad r3.indd 53 1 Zero-Max_2-16_Vs1.indd

1/19/16 10:19 1:11 AM PM 6/8/17

W I N D W A T C H

In a working turbine, SOHL organized cables look like this. Cables are secured by plastic separators and then by the steel band clamp on the outer circumference. The cables in the drip loop will need several of the units.

ties on a drip loop make the cables look organized, but it doesn't take a lot of thought to zip ties things together.

Anything tightly clamped or choking the cables will begin embedding into

The SOHL turnkey cable management system can guarantee pay off in reduced downtime alone. It’s a tested and proven system that eliminates cable wear and replacement costs. the jacket and insulation creating thin or weak spots,” he says.

Current bundling practices also prevent proper heat dissipation of the cables so they run hotter at the drip loop than intended, accelerating their life especially at weak spots in

18

WINDPOWER ENGINEERING & DEVELOPMENT

Wind Watch_6-17_Vs6.indd 18

www.windpowerengineering.com

the jacket. “Insulation tapes work OK patching stationary cables. But in the drip loop, it is a band-aid. Significant wear continues and the cable will need attention and possible replacement later,” he says.

The compact modular design of the cable glands allows for proper heat dissipation to keep the cables cool for maximum efficiency. “Diameter compensation is built-in so industryapproved high performance cables maintain their integrity and durability. The SOHL turnkey program includes kitted electrical cable-management components and expert installation. The cable management system can guarantee pay off in reduced downtime alone. It’s a tested and proven system that eliminates cable wear and replacement costs,” he says.

Systems One Services provides the install know-how. “It takes about half a day to install on existing cables and a full day if the cables are being replaced,” said Moorman. The number of snowflake glands and the install method is turbine specific. Therefore, installation by cable-connection experts ensures easy cable maintenance, replacement, and safer working conditions for technicians. W

JUNE 2017

6/8/17 11:27 AM

W I N D W A T C H

Conformal vortex generator and elastomer tab let NREL test turbine produce 22% more power CART2 turbine specs PARAMETER VALUE Model WWG-0600 Number of blades 2 Hub height

Rotor diameter Rated output

Rated rotor speed

36.6 m 43.29 m 600 kw 41.7 rpm

RIGHT: The plots show how the CART2 turbine performed with three arrangements of the CVG and Tab.

A COMPANY WITH ROOTS IN AEROSPACE has formulated a material and shaped it to provide vortex generation and leading edge protection in one package. Edgewind’s tough proprietary material, just 0.014-in. thick, sports a serrated edge for the vortex generator. Recent tests by the U.S. National Renewable Energy Laboratory revealed that when coupled with an elastomeric tab on the blade’s trailing edge, the turbine’s performance improved 22%.

The company’s business plan is also a bit different in that rather than sell the devices, it proposes to share the additional revenue from the increased power outputs. Although company finance director Richard George would not share the percentage figure.

Most vortex generators (VGs) appear as small tabs fastened perpendicular to a blade surface. Reports are that these “conventional” VGs improve production at best 2.5%, which is a significant figure. “The conformal vortex generator, or CVG, and tab offers the potential for operators to significantly increase their JUNE 2017

Wind Watch_6-17_Vs6.indd 19

wind farm production and ROI without adding additional turbines or capital investment,” said Edgewind’s CTO Peter Ireland.

He said that installation is accomplished quickly by rope or aerial lift. The work needs minimal surface prep, a visual alignment, and no special

CVG and Tab relative to industry standard edge protection tape on the Lab’s 600 kW CART 2 wind turbine in Golden, Colorado.

The CART2 blades, a zero twist, high-speed design, do not represent a current commercial turbine-blade design. However, its general power

Installation is accomplished quickly by rope or aerial lift. The work needs minimal surface prep, a visual alignment, and no special tools. tools. Also, an easy removal facilitates section repairs or replacement.

Edgewind has worked with NREL to collect data over an 11-month period on the performance of the windpowerengineering.com

curve does have a shape similar to commercial MW-scale turbines. Tests collected five-minute average power and wind-speed data, which was filtered to remove noise from unstable WINDPOWER ENGINEERING & DEVELOPMENT

19

6/8/17 11:27 AM

W I N D W A T C H

wind. Data for the baseline was limited at wind speeds over 15 m/s. Data for the CVG + Tab arrangement is still being collected.

More on the plus side: Ireland says that NREL reported a 122.2% increase in kWh production from the CVG and the Tab relative to a conventional leading-edge-taped blade. This shifts the power curve between the cut-in and full production wind speeds. An increase area under the curve indicates increased power productivity.

The Tab has a square cross section and could be adjusted several ways. But, says Ireland, adjustments depends on the geometry of the blades on which it will be used.

The company is looking for field trial sites in the U.S. and Europe to collect enough data to validate a CFD model, which will allow optimizing the design for each brand of turbine.

Furthermore, a wind farm ideal for further test would have about a 20-MW capacity or more in a prime wind generation location with stable, low-turbulent wind patterns. Sites NREL’s CART2 turbine provided a test should have General Electric, Vestas, or stand for Edgewind’s CVGs and Tabs.

Siemens Gamesa turbines.

The CVGs are just visible about midSite owners should have their length to the blade tip. own O&M staff that will be responsible for installing the CVG and Tab on two to three of their turbines. Edgewind will provide the CVG and Tab materials, installation training, and the LIDAR equipment required to measure wind speeds during the period of testing. Site owners will keep all additional power-generated profits during the field trial.

The field trials will assist in optimizing the CVG and Tab for different wind turbine models. Based on Edgewind’s experience from an aircraft tests, the company expects that specific optimizations for turbine models will yield additional increases in power. W

20

WINDPOWER ENGINEERING & DEVELOPMENT

Wind Watch_6-17_Vs6.indd 20

ABOVE: Looking down a CART2 blade shows the serrations at the edge of the CVG tape.

BELOW: The Tab, part of the Edgewind offering, has a nearly square cross section, a shape that might be optimized for each blade.

www.windpowerengineering.com

JUNE 2017

6/8/17 11:27 AM

W I N D W A T C H

WINDPOWER 2017 shows wind industry delivering on promises THE AMERICAN WIND ENERGY ASSOCIATION’S WINDPOWER 2017 Conference & Exhibition in Anaheim sported the tagline, “Bring your attitude.”

That positive attitude was evident from the event’s welcoming session straight through to its closing.

AWEA CEO Tom Kiernan pointed out in his opening speech that wind power has developed and delivered as JUNE 2017

Wind Watch_6-17_Vs6.indd 21

promised. “We said more wind could be reliably added to the grid, that with stable tax policy we could grow jobs, and that with a level playing field we would invest in America. Well, we delivered.”

Five states already derive over 20% power from wind, and today over 100,000 Americans are employed in the wind industry. In fact, the U.S. wind industry added jobs over nine times faster than

WINDPOWER 2017 brought a “Brand New Attitude” to the conference and exhibition in Anaheim this May. As one of the most affordable and reliable forms of electricity generation, wind leaders at the show agreed that it will play an increasingly important role in the state and nation’s expanding clean energy mix.

the overall economy in 2016. The industry also recently reported its best first quarter in eight years. Over 908 utility-scale turbines were installed in the first quarter of 2017, for 2,000 MW of added capacity.

What does that mean for American workers? “Each new modern wind turbine supports 44 years of full-time employment over its lifespan, so the turbines we installed in just these three

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT

21

6/8/17 11:27 AM

W I N D W A T C H

months represent nearly 40,000 job-years for American workers,” stated Kiernan.

Given that the industry is now in year three of a five-year phase-down of the Production Tax Credit (PTC), it is perhaps of little surprise the sector is both strong in attitude and hard at work. Navigant Consulting recently forecast a strong

is to embrace all forms of support to help forge the necessary policies and regulations for wind to thrive,” he added.

AWEA is working on that. In March, the organization sent a co-signed letter (that included the National Electrical Manufacturers Association, the Solar Energy Industries Association, WIRES, and other

Tom Kiernan, CEO of AWEA, looks on as newly elected AWEA Board Chair, Tristan Grimbert, speaks out for wind power during the event. (Photo: AWEA)

2017, and expects the PTC to enable development of about 35,000 MW of wind-power capacity across the country between 2017 and 2020.

Newly elected AWEA Board Chair (and President and CEO of EDF Renewable Energy), Tristan Grimbert, pointed out that progress typically involves hurdles. “With wind’s success comes new and solvable challenges,” he

groups) to a number of Senate majority leaders urging Congress to invest in a more secure, cost-effective transmission grid.

“Investment in new transmission lines will modernize the U.S. grid and deliver more clean energy to population centers,” Kiernan said in a related release. New transmission also creates jobs and rural economic development, while delivering lower electricity prices.

regulators are working to integrate more wind-generated power in their systems.

For example, Xcel Energy’s Colorado Balancing Authority already runs on 20% renewable energy, and Southwest Power Pool (which manages power across 14 states), is also nearing 20% wind yearround. PJM, the country’s largest grid operator, recently determined it could reliably handle over 75% wind power.

“Wind can stay attractive,” said Buzz Miller during the closing session. He is the President and CEO of Southern Power.

“You fix some of the transmission issues around, stay vibrant, and we can get through [the PTC phase out],” said Miller.

“By continuing to get cost competitive, continuing to improve the wind-energy product – it’s already great – you’ll capture a lot of potential customers out there, not only public utilities and corporate purchasers, but municipal utilities, rural co-ops, and others,” he said.

As the top renewable-energy source in America, wind has had little problem attracting Fortune 500 brands, such as GE, Amazon, Microsoft, Walmart, and Facebook, which have all purchased wind energy.

Over 24 American cities have also committed to running on 100% renewables.

City of Mercer Island, Washington for example, recently announced it is moving toward 100% wind power.

“Wind power has grown to be America’s largest source of renewable capacity because we’ve delivered on our promises,” Said Kiernan.

Next year’s WINDPOWER event will be in Chicago, May 7 to 10. It will be interesting to see what new promises the wind industry makes good on by then. W

Investment in new transmission lines will modernize the U.S. grid and deliver more clean energy to cities. said. Case in point: “Grid management must evolve to meet these challenges.”

Grimbert said competing in the low-price energy market will take increased and improved transmission, and fairer market rules. “A new attitude 22

WINDPOWER ENGINEERING & DEVELOPMENT

Wind Watch_6-17_Vs6.indd 22

A study from the Energy Department released in January confirmed that even limited additions to transmission capacity would allow for more wind energy, and supply 35% of U.S. electricity by 2050.

For now many utilities and grid www.windpowerengineering.com

JUNE 2017

6/8/17 11:27 AM

Wind work around North America According to the American Wind Energy Association’s latest quarterly market report, wind added more megawatts in the first quarter of 2017 than in the first three quarters of last year combined. Over 900 turbines were erected,1,781 MW of longterm contracts signed, and some 2,000 MW of capacity installed — which marks the strongest start for the wind industry in eight years. New turbine installs have already spanned from Rhode Island and North Carolina to Oregon and Hawaii. Great Plains states, Texas (724 MW) and Kansas (481 MW), are current pack leaders. What’s more is North Carolina became the 41st state to harness wind power, bringing online the first wind farm built in the Southeast in 12 years.

7

3

5 6

W I N D W A T C H

5

United Wind plans to offer its WindLease program through the Farmers Business Network’s (FBN). The agreement means WindLease will let FBN members lease a small-wind system for no money down to stabilize electricity costs over the longterm, and save on utility bills from day one.

United Wind will handle construction and maintenance, so customers can focus on wind-farm operations.

2

6

8

4

Construction starts on Texas’ community-sponsored wind farm

3

The first phase of Tri Global Energy’s 197.6-MW Bearkat Wind Energy Project has reached financial close and is now under construction. The company developed Bearkat using its business model, the Wind Force Plan, which lets local landowners and community investors share ownership in the leased wind project on their land.

2

Block Island switches from diesel to offshore wind

A few weeks ago, Rhode Island’s Block Island went dark in a pre-planned sequence of high-voltage switching intended to shutdown the diesel generators. Lights were then turned back on, and fully powered by the nation’s first offshore wind farm. Block Island Wind, which is owned and operated by National Grid, is now operational and saving nearly one million gallons of diesel fuel annually.

JUNE 2017

Wind Watch_6-17_Vs6.indd 23

U.S. Senators propose “100 by ’50” clean-energy act

7

EDF adds vortex generators to U.S. turbine fleet

8

A number of U.S. Senators have introduced landmark climate legislation that would transition the United States to 100% renewables.

The “100 by ’50 Act” lays out a roadmap for the clean-energy transition by no later than 2050. It is the first bill introduced in Congress that sets forth a plan for a fully fossil-fuel free future for the country that is economical and sustainable.

4

Maryland moves one step closer to offshore wind

US Wind, Inc. received its final air-emissions permit to install a meteorological tower in the Maryland Offshore Wind Energy Area, and plans to submit an application for a Construction and Operations Plan later this year. The company intends to build a 750-MW project with up to 187 wind turbines, 12 to 17 miles off the coast of Ocean City.

1

1

United Wind brings distributed wind to farmers

O&M provider, EDF Renewable Services will collaborate with experts at 3M to install 3Ms Wind Vortex Generators on turbines across the U.S. Vortex generators optimize wind flow around a blade, stabilize aerodynamics balance load effects, reduce noise due to reduced stall, and can increase AEP by 2 to 3%.

windpowerengineering.com

Illinois tests first U.S. utility-scale microgrid

Ameren has completed a $5 million, advanced utility-scale microgrid at their Technology Applications Center, adjacent to the University of Illinois. The microgrid tests monitoring and control methods for aggregating renewable sources from wind, solar, and natural gas – with advanced automation and battery storage. It is one of the few in the world that operate at utility-scale voltages between 4 and 34.5kV, with multiple levels of control.

Pattern Energy acquires New Mexico wind & transmission projects Pattern Energy has acquired interests in the two wind projects that comprise the 324MW Broadview Wind power facilities in New Mexico, and interconnect transmission line.

Broadview Wind consists of 141 Siemens’ 2.3-MW turbines, with a 324-MW generation capacity. The wind farm interconnects to the Western Interconnect transmission project, a 345-kV line about 35 miles in length.

WINDPOWER ENGINEERING & DEVELOPMENT

23

6/8/17 11:27 AM

RE L I ABI L ITY

Robert J. Marotta Product Sales Manager Accumulator Cooler Division Parker Hannifin

A 1.5-MW wind turbine with an open-loop cooling system may have a $20,000 problem. Coolant in the insulated-gate bipolar transistor circuit is a critical issue that may require turbine downtime.

Fortunately, there is a way to prevent the need for continuous coolant monitoring without taking turbines offline.

A better way to prevent power electronics from overheating in wind turbines

O

ne little discussed but important function of an efficient wind turbine is temperature control. The electronic equipment and circuits installed in a turbine must operate reliably in spite of temperature fluctuations over its lifetime.

An unexpected change, and particularly a rise in temperature, can turn into a costly problem for wind-farm owners if left unchecked. Liquid cooling systems are typically used to address potential thermal changes in a wind turbine’s power electronics. But even the best quality coolant is not a failsafe in all conditions.

One after-market product is working to eliminate unexpected problems and downtimes associated with restoring coolant mixes or potentially damaged turbine components.

24

WINDPOWER ENGINEERING & DEVELOPMENT

Reliability_6-17_Vs4.indd 24

Overheating A sudden or unexpected excessive internal temperature rise can lead to water evaporation and loss of coolants in critical turbine cooling systems, and may eventually cause the turbine electronics to overheat. This is a particular concern in machines with an open-loop cooling system and can occur even with the use of high-quality coolants.

An open-loop system lets water gradually evaporate from the water-glycol coolant in the insulated gate bipolar transistor (IGBT) circuit, particularly during warm weather. (IGBTs are an electronic component typically used in turbines because of their fast and efficient switching capabilities.)

A problem may occur when the water evaporation lowers the coolant level and elevates

www.windpowerengineering.com

JUNE 2017

6/8/17 11:29 AM

AeroTorque Double Warranty FP Ad1HR.pdf

1

9/8/16

4:20 PM

No Spalling, No Axial Cracks, No Damage, Period!

For a limited time, if you install an AeroTorque WindTC when you install new bearings, AeroTorque will

DOUBLE YOUR WARRANTY!

C

M

Y

CM

MY

CY

CMY

®

K

Protect your investment before the damage begins! *Conditions apply - contact AeroTorque for details.

AeroTorque RE Handbook 17.indd 29

www.AeroTorque.com 330-590-8105 6/8/17 10:11 AM

RELIABILITY

the mixture’s concentration. If the system is left unchecked and unmaintained, the resulting mix imbalance inhibits the cooling properties of the fluid. This potentially compromises the IGBT. Needless to say, a loss of IGBT components because of overheating can result in costly hardware losses and significant turbine downtime. To avoid this, wind operators have typically “bandaged” the problem with a regular cadence of coolant monitoring, water replenishment, and re-balancing of the cooling fluid mix.

This approach can work when diligently adhered to, but it is a costly maintenance plan. It requires taking both the turbine and transformer offline, which also means turbine downtime and lost revenue for the wind farm.

Kleenvent KV-CEI eliminates water evaporation in a wind turbine’s coolant and stops ingress of airborne contaminants by closing off the cooling loop from the outside atmosphere.

The unit eliminates the need for continuous coolant monitoring, particularly during warm weather. It typcial provides a return on investment in one year.

26

Closing the loop To remove maintenance downtime necessary to restore coolingfluid levels, one company is essentially closing the loop on the open-loop cooling system. Parker Hannifin’s customdesigned KV-CEI after-market product works to eliminate water evaporation by containing the water vapor in a closedloop, add-on system. It then condenses it back into a liquid to maintain a constant water-glycol ratio to optimize the efficiency of the cooling system.

“Because owners and operators are spending budgets and time to maintain IGBT coolant levels in open-atmosphere cooling systems, the overall cost of maintenance, replacement fluids, and reduced reliability adds up quickly,” explains Bill Mosher, Division Engineering Manager at Parker Hannifin. “The solution our engineers designed eliminates water evaporation by containing the water vapor in a closed loop add-on system.”

The current product is targeted at owners of 1.5-MW wind turbines that use an open-loop water-glycol based IGBT cooling system.

“By maintaining a constant water-glycol ratio, we ensure the cooling system’s efficiency,” Mosher adds.

“The results are reduced monitoring and improved turbine reliability, which net higher productivity and uninterrupted

WINDPOWER ENGINEERING & DEVELOPMENT

Reliability_6-17_Vs4.indd 26

power generation and revenue streams for wind-farm owners.”

How it works KV-CEI isolates electronic systems from airborne contaminants, dust, chemicals, and water vapor evaporation. It is an enclosure that works by closing off the coolant loop system from the outside atmosphere (where evaporation escapes) with a breather bladder. Outside air inflates and deflates the bladder when fluid levels inside the isolation tank expand and contract from system liquid temperature changes.

A low-pressure relief valve helps prevent system over-pressurization in case unforeseen air becomes trapped inside the fluid lines. An open-close, air-exhausting valve lets the system drain and refill with the proper fluid levels during a normal preventative maintenance cycle.

By isolating the internal volume of the reservoir from the existing outside atmosphere, the system prevents evaporation of water from, and the ingress of airborne contaminants into, the water-glycol solution. A check valve provides over-pressure protection, and a visual level indicator allows local confirmation of the coolant level.

In addition, a port allows adding an optional, industry-standard, liquid-level float switch for remote low-level coolant indication.

“The KV-CEI design is versatile enough to allow the addition of lowlevel liquid sensors when needed in a turbine.” Mosher says custom systems are also possible. “We also can design many mounting options to fit a particular mounting pattern.”

The aim is to keep wind turbines generating energy in even in extreme temperatures, without adding more maintenance visits to a site.

“The return on investment for the KVCEI solution can be measured in as little as a few short weeks in warmer climates and at elevated operating temperatures,” says Mosher. W

www.windpowerengineering.com

JUNE 2017

6/8/17 11:30 AM

Travis Jones, NRG Systems Engineering Technologist

We may look different, but we are still the same company you know and trust.

Our turnkey wind resource and optimization solutions are designed with our customers in mind, which is why we are constantly refining our technology and developing new tools to meet your needs.

We are still with you every step of the way. nrgsystems.com

NRG_6-17.indd 29

6/8/17 10:17 AM

B O LT I NG Paul Dvorak Editorial Director Windpower Engineering & Development

Norbar’s EvoTroque2 comes in about 10 models. Its weight, 30 to 50 lbs, depends on the selected torque output. Its torque ranges from 74 to 5,200 foot-pounds and can record the torque applied to 3,000 bolts. Every model is available in 110 or 230V.

7 ways electric tools simplify and improve bolting jobs

T

he persistent bolting problem in wind turbines and most other construction is that it requires so many different tools. That means erecting a wind turbine and its tower might make use of hydraulic, electric, manual, and sometimes pneumatic tools. To make matters worse, the pumps and tools are heavy and their hoses can pose a safety hazard. Then there is the noise from working in a steel drum. Try warning someone of a safety hazard when workers above and below are making a racket. That is the opinion of Dominic Ortolani, Application Engineer with Norbar, a manufacturer of precision, high torque bolting equipment.

There is good news, he says. Most manufacturers are constantly asking for feedback from the field on how to make their tools better.

“Then we take the ideas to our engineers, asking how can we make it more compact, for example, yet still maintain accuracy and high torque,” says Ortolani. While electric torque multipliers are not new, demand for them has increased recently thanks to improvements in accuracy, reliability, and

28

WINDPOWER ENGINEERING & DEVELOPMENT

Bolting_6-17_Vs2 pd.indd 28

capability. In seven ways, he says, electric bolting tools are solving construction problems.

1.Relatively compact. “We are finding that one recent electric-torque multiplier can fit into areas that other previous customer tools could not. And they’re finding more uses for multipliers where they were using hydraulics before,” says Ortolani.

2 Accuracy. Ortolani says accuracy refers to the precision with which the tool delivers torque.

“For example, the EvoTorque 2 electric-torque multiplier delivers torque to within 3% of its setting. We calibrate the tools to 3%. Accredited calibration labs use traceable equipment, so you can see when the tool was calibrated and the equipment it was calibrated on. This ensures the maintenance of accuracy. Also, there are real cost savings involved when you can cut job time by 50% or more,” says Ortolani.

All EvoTorque2 units have what Ortolani call joint-sensing technology. “It means as the wrench

www.windpowerengineering.com

JUNE 2017

6/8/17 11:36 AM

B O LT I N G

torques down on a bolt, it is sensing the type of joint, by its hardness or the softness and the rate of torque rise, and adjusts accordingly to maintain a proper speed and accuracy, so it does not overshoot or undershoot the torque target,” he says. This is important because there’s a manufacturer’s recommendation for almost every bolt application that says: “Don’t over-tighten this because it can do more damage than good.”

3. Simplicity. The operator must input the torque specs for the anticipated work and that allows applying several values, such as a torque figure alone, or a torque value followed by an angle of rotation.

“With torque targets set, a user puts the tool on the bolt and pulls the trigger.

You have one electrical cord and it is considerably quieter than hydraulic tools.

Hydraulics, on the other hand, require pumps and hoses that make operating one tool a two-man job,” says Ortolani.

4. Low noise. This is a bigger deal than you think. “Consider the safety risk that comes with noise. If you have guys in multiple areas up a tower, everything echoes and bounces off the walls. If a safety event occurs on the deck above you, it’s likely you will not hear them. Using a quieter tool makes it easier to hear in case something does happen,” he says.

5 Quality assurance. Data reporting on all of maintenance cycles is a more frequent requirement. “Every time a user tightens a bolt, quality-assurance requirements call for recording the data for later examination. Should the maintenance or construction team ever get audited, they would like to have a file telling that a particular tool was calibrated on this date, used by this worker in this tower, and on this bolt. That report would also show that things have been done by the book.”

6. Higher torque values. As the towers are built larger, such as with offshores WINDPOWER ENGINEERING & DEVELOPMENT

Bolting_6-17_Vs2 pd.indd 29

NO LIMIT SERVICE FOR A NO LIMIT INDUSTRY Enerpac Bolting Products - Torque Wrenches & Pumps

Electronics / Torque Tools

Skidmore-Wilhelm Bolt Testers

Stahlwille Torque Tools

24/7 Service - Call Us

832-271-5120

520 Dallas St. League City, TX 77573

aztecbolting.com

29

6/8/17 11:37 AM

B O LT I N G

The user interface in the EvoTorque handle lets users set torque values that the tool will deliver. Data transfer is by USB or Bluetooth 4.0.

towers, the torque requirements also increase. “The bolts and structures are getting larger, so we’re constantly trying to adapt. Highest construction torque requirements now range from 15,000 to 20,000 Nm. 7. Improving on current practice.

Typically, after tightening a bolt, the technician marks the bolt position by drawing a line on it and its contacting surface. “The line tells that the line is where it was last tightened to. Later in a maintenance cycle, after reapplying the torque, a worker can see how the bolt moves and decide whether that is OK or not so good,” says Ortolani.

“We have a solution for that practice as well in the EvoTorque2. It will measure a pre-tightened bolt and record the degree of rotation so you don’t over-torque the joint. You don’t want to hit the nut with full-speed torque because the bolt’s going to move no matter what. So we developed technology that senses and 30

WINDPOWER ENGINEERING & DEVELOPMENT

Bolting_6-17_Vs2 pd.indd 30

measures the pre-tightened value without slamming into it. That tells how the bolt and joint are performing over time.”

What’s more, construction personnel might have recorded data on paper.

“And as people sometimes do, they may write down the wrong number. That error could cause problems. So automatic data recording is a useful feature,” he says. An EvoTorque 2 can store 3,000 readings.

“So when torquing a bolt, the tool is recording actual torque output, and other details to the second. Even if a worker takes 20 minutes per bolt, that will be recorded.”

Users are always trying to eliminate cords and use more compact or lighter tools. Electric is the way to go and as batteries improve, they will allow more innovation. W

www.windpowerengineering.com

JUNE 2017

6/8/17 11:37 AM

win

ENE R GY STOR AG E

Michelle Froese Senior Editor Windpower Engineering & Development

Microgrid system to stabilize grid power in Alaska An innovative microgrid will improve power stability and test scalability for about 300,000 people in Anchorage, Alaska.

The new system will integrate power from a 17-MW wind farm on Fire Island, and work in concert with flywheel and battery storage.

F

ire Island is a small island near the top of Cook Inlet in the Municipality of Anchorage, Alaska. While it once served as an Air Force station, the island now sits vacant other than a private FAA aviation airfield and a wind farm.

The 11-turbine, 17.6-MW wind farm, built by Fire Island Wind LLC in 2012 (a subsidiary of island owner Cook Inlet Region Incorporated or CIRI), is the first megawatt-scale project in South-central Alaska. According to Fire Island Wind, the aim of the project was to ease the strain on the natural gas supply in Cook Inlet.

Although the wind farm can generate more than 50,000 MW-hours annually for utility Chugach Electric Association, leveraging the project’s full capacity has been a challenge over the years.

“Power usage of this wind farm is relatively low,” says Massimo Danieli, President of ABB’s Grid Automation division. ABB is a power technology company currently working with Chugach Electric on better management of the Alaskan transmission grid. “The wind farm sells roughly 4% of the retail

JUNE 2017

Energy Storage_6-17_Vs2.indd 31

capacity of Chugach Electric, so it is not a large proportion or quota of the overall electricity sold by the utility into the Anchorage area.”

Upon completion of the wind farm, Fire Island Wind entered into a long-term power purchase agreement with Anchorage-based utility. The 25year contract provides a flat net price of $97 per megawatt-hour throughout its term.

“A problem for Chugach Electric is an often changing load and supply.” Danieli points to the variability of wind, along with a number of different energy sources, that feed and impact the local transmission system. Anchorage is served by wind energy, hydropower, gas, and fire or thermal capacity. Transportation of fuel is another concern.

“The city has ports, which can mean heavy transport loads coming from vessels and cranes. This can lead to further pressure on the utility to keep up with ongoing power demands,” he says. “To better manage the load and demands, Chugach Electric needs to add regulatory capacity to the transmission grid, which, at only about 500 MW, is not a very large system.”

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT

31

6/8/17 11:43 AM

ENERGY STORAGE

There is also talk of expanding the wind farm. CIRI wants to double the number of wind turbines on Fire Island from 11 to 22. It announced a framework deal with utility Golden Valley Electric Association late last summer. So there may be more wind power on the way.

For now, Chugach Electric is working with ABB on a “microgrid stabilization” project that will improve power stability, test scalability, and identify a system that enables the integration of more renewables. The project will combine battery and flywheel-based storage.

“The two devices — the flywheels and lithium-ion batteries — will connect to the grid together with a control system we call PowerStore,” says Danieli. “This system has the important task of master control by monitoring and sharing power

of the transmission grid. Ultimately, it is in charge of when energy should sync into the flywheel or battery storage. “It also has to ‘decide’ when to release energy,

quickly reduce the life of that battery.”

Batteries may work well for storing or generating a constant flow of energy, but they are less than ideal for sudden

If tomorrow the size of the wind farm becomes twice what it is today, as may be the case at Fire Island, there will be a PowerStore with twice the capacity. first from the flywheel and secondly from the battery,” says Danieli. “It is constantly assessing and redirecting the power supply or surplus.”

Lithium-ions are the battery of choice here because they are a lowmaintenance, high-density battery. One other advantage of lithium-ion cells is that their rate of self-discharge is much lower

or abrupt changes, such as those that occur at wind farms. Enter the modern flywheel. It consists of a large rotating mass supported on a stator by magnetic bearings. Furthermore, it typically operates in a vacuum to reduce drag.

Flywheels can bridge the gap between short-term power and long-term energy storage with excellent cyclic and

ABB’s PowerStore is a compact and versatile flywheel-based microgrid generator. Its main purpose is to stabilize power systems against fluctuations in frequency and voltage.

capacity across the wind farm, flywheel, and battery. Its goal is to continually maintain grid stability.”

He explains that the flywheel and battery will connect to the grid and act like two generators. “Together, they can take in, sync, and release power to ensure a stable online frequency — in fact, it is very much like a form of load sharing.”

While the two power devices work to share the load, the PowerStore control system continuously monitors the status 32

WINDPOWER ENGINEERING & DEVELOPMENT

Energy Storage_6-17_Vs2.indd 32

than that of other rechargeable cells, such as Ni-Cad and NiMH forms.

But why the need for a battery and flywheel? “It is proven that when you have high variability of power generation and a sudden heavy load on the grid, such as when you have strong wind gusts at a wind farm, it is necessary to release that energy quickly to maintain the frequency or stability of the transmission system,” shares Danieli. “Try that over several cycles on a battery used for storage, and you

load following characteristics.

“The PowerStore system uses a flywheel for fast release and sync of power, which can go up to one megawatt per second and then back down again. So, these fast variations are managed by a flywheel, where it excels, and the slower variations are dealt with through battery storage,” he explains.

High-speed software controls the power flow into and out of the

www.windpowerengineering.com

JUNE 2017

6/8/17 11:43 AM

ENERGY STORAGE

flywheel, essentially making it a high inertia, electrical shock absorber that can instantly smooth out power fluctuations.”

The hybrid system prioritizes one over the other, flywheel or battery, depending on the system conditions,” says Danieli. “It rapidly stabilizes voltage, but also improves power quality by absorbing or injecting that power to ensure a smooth network.” PowerStore can stabilize voltage and frequency, hold 18 megawatt-seconds of energy, and shift from full absorption to full injection in one millisecond to stabilize the grid.

What makes ABB’s microgrid system ideal for integration with the Fire Island wind farm is that it is modular and made for extreme weather conditions.

“If tomorrow the size of the wind farm becomes twice what it is today, as may be the case at Fire Island, there will be a PowerStore with twice the capacity. The equipment itself is modular and contains all the connections needed to build on one another or increase in capacity.”

Danieli explains further. “Say you add another 10 or 20 turbines to your wind farm, from a microgrid standpoint, you simply add a small controller for each turbine to the network, and they automatically link up to the network and start co-operating with the other controllers.”

The system is built for efficiency and to minimize installation times. It is also built to endure the Alaskan climate.

“The system is extremely robust and made to last in harsh conditions,” he says. “The lithium-ion batteries, of course, have a degradation period that is in the range of years. But this also depends on the way they are used and maintained.” Danieli says the units are equipped with air conditioning to better sustain the electronic equipment and to evacuate gases and elements that could build up inside the batteries. “There is definitely a bit of art and engineering in making sure the equipment is made and used appropriately.”

JUNE 2017

Energy Storage_6-17_Vs2.indd 33

A well-devised O&M plan is essential along with system versatility.

As more microgrid and energy storage projects develop, the equipment supporting these systems must fit each climate and application.

“One cannot say that this industry is booming yet because I think that most numbers or predictions given on the microgrid market are probably a little optimistic, but we are seeing more and more projects,” he says. “And what’s interesting is that they started in only remote areas, and now projects are

developing in other locations where the grid is weak or where there are opportunities to add renewable capacity and storage behind the meter.”

Danieli says regulatory framework in most places still needs to catch up to the advances in microgrid equipment and technology, but the possibility to install these systems is now available to utilities and grid managers. “We’ll see more microgrid systems in the near future, I think, and not just in remote places such as Alaska, but maybe closer to home, providing service to local grids.” W

Flywheels can bridge the gap between short-term power and long-term energy storage, and offer excellent cyclic and load following characteristics.

ABB’s Microgrid Plus control system monitors the hybrid storage system to ensure proper load sharing between the two storage mediums (flywheel and battery). It is also equipped for remote service and maintenance, which makes it ideal for use in Alaska.

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT

33

6/8/17 11:43 AM

SA F E TY Michelle Froese Senior Editor Windpower Engineering & Development

Safety tips all wind techs should know It’s been said that practice makes perfect, and the life of a wind tech means there is little margin for error. To this end, it is important to train as much as possible with different gear and equipment to gain experience and, most importantly, ensure worker safety whether at height or on the ground.

W

ind technicians face hazards every time they climb atop a wind turbine. The hazards waiting include those from heights, high voltage, overhead and rotating equipment, and exposure to unforgiving weather. If help is ever warranted because of injury, it is typically hours away from most remote wind farms.

However, the job of a wind technician can be a safe and successful one, according to Auston Van Slyke, a Program Director at Colorado’s Ecotech Institute, the first and only college in the U.S. focused entirely on careers in the fields of renewable energy. Van Slyke was once a traveling wind technician himself, and currently teaches a 60-hour wind-turbine safety course at Ecotech.

He says proper gear and training are keys to a safe career as a wind tech. This may seem simple enough, but with so many fall protection and personal protection equipment (PPE) choices on the market, making the right one is sometimes daunting.

“What wind technicians should suit up in at a jobsite is now a complicated and argued topic,” he shares. “From steel-toed boots to fire-retardant clothing, there are a lot of choices in PPE. And 34

WINDPOWER ENGINEERING & DEVELOPMENT

Safety_6-17_Vs2.indd 34

not everyone in the industry can agree on what is required of a tech because the job is different every day and at every wind site.”

Van Slyke points out that National Fire-Protection Association’s NFPA 70E sets the basic requirements for working around electricity. These standards have changed recently, so it is essential that wind techs keep up with current regulations. According to NFPA’s website, 70E was first developed at OSHA’s (the Occupational Safety and Health Administration) request, and it “helps companies and employees avoid workplace injuries and fatalities due to shock, electrocution, arc flash, and arc blast.”

Safety gear that supports the regulation can include rubber electrician gloves, face shields, earplugs, and fire-retardant clothing. “There may be choice in some attire, but all wind techs should know NFPA 70E to ensure their safety when working near electricity. There are some electrical cabinets in a wind turbine that require workers to suit up in what looks like a bomb suit,” he says. “But better safe than sorry.”

The same can be said for turning on or off electrical equipment. “There are really five safety topics every wind tech should know: PPE,

www.windpowerengineering.com

JUNE 2017

6/8/17 11:45 AM

AWEA_6-17.indd 29

6/8/17 10:13 AM

SAFETY

working at heights, tools, drop prevention, and LOTO,” says Van Slyke.

LOTO, or Lock Out Tag Out, is used in industry to ensure hazardous equipment is properly shut off and kept off until after maintenance work is complete.

LOTO is not unique to wind sites, but it is a procedure wind techs do daily at a job site. “A lot of companies have developed their own guidelines for following the correct procedures, but I break LOTO down into seven steps,” says Van Slyke.

TOP: Hand injuries from misuse of tools and equipment are the number one cause of injury for wind techs. Before working onsite, make sure the equipment is safe to de-energize and verify a zero-energy state with the appropriate safety checks.

RIGHT: Safety gear that supports OSHA regulations can include rubber electrician gloves, face shields, fireretardant clothing, and full-body arc-protection suits.

It is always better to be safe than sorry. (Photos: Ecotech Institute)

36

1. Identify the energy source, communicate intent, and make sure the equipment is safe to deenergize.

2. Turn off the energy, and lock and tag them. Note that some components lock in the off position, while others might require install of a cover or bracket.

3. Verify zero energy state with hot-cold-hot and 6-point checks. A hot-cold-hot check is the act of measuring for voltage to make sure the onsite meter is working, and then measuring equipment that was just turned off to ensure zero voltage is present. A 6-point check is important when working with three phases of power — first measure from the ground to each phase of power, and then from each phase to the other.

4. Protect against unexpected energizing, and stay out from harm’s way as much as possible in case equipment becomes re-energized.

5. Perform work carefully. Keep safety barriers in place and use appropriate tools and PPE at all times.

WINDPOWER ENGINEERING & DEVELOPMENT

Safety_6-17_Vs2.indd 36

6. Make sure equipment is safe to re-energize, and communicate your intent at the jobsite.

7. Turn on energy slowly. Turn on the system starting with the safest circuit first.

“These steps apply to turning off electricity running to or from equipment before an inspection. But it also applies to locking the rotor when entering a turbine hub,” says Van Slyke. “It is one of the most important safety tasks at a wind site.”

Of course, another important and high-risk task of a wind tech is working at heights. “A wind technician has a relatively safe job — providing they follow all the rules and use proper gear.” Van Slyke says that when it comes to going up and down turbine towers, he trains technicians for three features: climbing, positioning, and rescuing.

“Safe climbing involves two important steps. The first, the 100% rule, means a climber must be tied off to an anchor point 100% of the time, no exceptions,” he says. This entails connecting to a new anchor point before disconnecting from the last one prior to moving forward in a climb.

The second step is three points of contact. It refers to the safest way to climb: two feet and one hand or two hands and one foot. “A wind tech must always keep three points of contact on the ladder to avoid the risk of slipping or falling off the rung,” says Van Slyke. “And no matter how important the job is at the top or back down at the base, it is more important to move slowly and carefully when ascending or descending a tower. You don’t have to fall from very high to get hurt badly.”

Positioning is particularly important if work on equipment from a ladder is part of a job up-tower, he says. “This requires an adjustable lanyard that can securely hold a climber’s weight, while providing some leverage so that he or she can safely lean out and away from the tower to work. A cable slide is not recommended for this purpose.”

Most wind-farm owners and operators have their own preferred

www.windpowerengineering.com

JUNE 2017

6/8/17 11:45 AM

SAFETY

fall-protection equipment, so it is important to train on and practice with the one in use at each job site.

“This is especially true for rescue training,” says Van Slyke. “It’s necessary for all techs to familiarize themselves with how to use the lanyards, ladders, and fall-protection equipment at each and every jobsite. Train with each different product type and brand, and then practice, practice, practice.” Someone’s life may depend on it one day.

Safe tool use is another topic Van Sluke covers during his training program. “Much like PPE, there is an overwhelming number of tools to choose from as a wind tech — just ask your local Fluke or Snap-On Tools’ sales rep,” he says. But choosing the right one for the job takes skill. Case in point: Using the wrong type of electric meter is the leading cause of electrical injury, says Van Slyke. “And, perhaps not surprisingly, hand injuries from misuse of tools are the number one cause of injury for wind techs.

Hydraulic power-torque wrenches have pinched off many fingers because of improper use, and bolts can easily be over torqued and broken if the settings or procedures are incorrect.”

That means improperly trained techs risk injury to themselves and damage to wind-turbine equipment.

“Every wind tech needs to have training on their tools and for each new tool they use at a wind site to protect the entire jobsite,” he says.

Another hazard when working at heights is the risk of dropped tools or objects. “It’s quite simple,” says Van JUNE 2017

Safety_6-17_Vs2.indd 37

Slyke. “If you are working at heights, don’t drop anything. Just don’t. There are slings, strings, bungees, magnets, and swivels that can help ensure nothing will fall. Never use a tool at heights that is not safely tied off to something. There are no excuses here.”

Nevertheless, all site personnel should protect themselves as much as possible. “If you are not up-tower but the one on ground support, then make sure to wear the appropriate hard hat.”

Van Slyke says that the hard-shell bump cap that wind techs typically use is not enough to protect from falling objects.

“Rigging the tools and equipment to cranes, hoists, and winches is a daily task and should not be taken lightly.

Using the appropriate connectors and slings are imperative for personal safety, and safety of all those onsite.”

The one lesson he stresses repeatedly when teaching new technicians: avoid shortcuts. “Don’t get lazy with safety and PPE equipment,” says Van Slyke. “I can’t stress this enough. Every tech should know what gear to use and how to use it correctly.

Training is essential for the safest industry possible. W

The most effective way to ensure worker safety at a wind site is proper and ongoing training. A properly trained wind tech will understand how to safely don PPE, climb a tower, work in a nacelle, and with high-voltage equipment.

He or she will also learn to seek the requirements of each specific jobsite.

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT

37

6/8/17 11:45 AM

F I RE PREVENTION

Judah Moseson Vice President, Business Development Cooke Power Services

Turbine fires and how to prevent them

W

ind turbines have undergone a series of transformations since their inception. Manufacturing revisions and O&M programs have addressed many concerns. However, one issue that still requires more discussion and action is fires in the wind-turbine nacelles. The root causes require attention from both turbine manufacturers and wind-farm operators.

Fire and forensic investigators have researched wind-turbine nacelle fires with mixed findings.

There is more than one root cause for the fires because turbines are produced by different original equipment manufacturers, OEMs. Some turbine fires start due to electrical and mechanical root causes. Electrical root causes are mostly related to up-tower transformers, control cabinets, and power-converter systems. The

electrical sources of the fires may result from arcing around cable terminations and bus connections made during the manufacturing process. Others occur because of improper operations and maintenance practices.

Most mechanical fires start by the main-shaft bearings and hydraulic brake systems, and result from overheated brakes and bearings. Overheating in the nacelle may result from a lack of proper lubrication, so a good O&M plan is essential.

To better prevent turbine fires, OEMs should redesign units to eliminate manufacturing issues contributing to electrical incidences and then provide retrofits for existing units. Lubrication requirements should also undergo review to help eliminate poor oil quality or lubricant maintenance as a root cause. Unfortunately, that is not happening across the board.

It’s a sad sight but it happens. Turbine fires have been traced to electrical and mechanical issues.

38

WINDPOWER ENGINEERING & DEVELOPMENT

Fire Prevention_6-17_Vs2 pd.indd 38

www.windpowerengineering.com

JUNE 2017

6/8/17 11:47 AM

FIRE PREVENTION

Hawkeye

®

Videoscopes

Fast, Reliable, Affordable, Visual Inspection!

90° Prism & Close-Focus tips available!

If you have had a turbine fire, read the investigators report to ensure you understand its root causes.

• Sharp, Clear Photos & Video • Large 5-inch LCD Monitor

What can we do?

1) If you have had a turbine fire, read the investigators report to ensure you understand its root causes.

2) Consider the installation of a firesuppression system to eliminate the spread of a potential future fire. Such a system can limit the damage by keeping the fire localized. If the fire cannot be stopped from igniting, then it is at least possible to help prevent it from spreading.

3) Fully understand lubrication requirements for wind turbines, and adjust O&M plans to ensure that all units are properly lubricated. This will help prevent nacelle fires and extend the life of rotating equipment.

Lastly, speak up. Share preventative measures with the wind industry to potentially help others keep their turbines running safely. W

• Easy-to-Use Controls • Annotation Feature • Rugged Tungsten Sheathing • Quality Construction • Precise 4-Way Articulation • Starting at only $8,995

VIDEO BORESCOPES

In stock, ready for overnight delivery!

Hawkeye® V2 Video Borescopes are fully portable, finely constructed, and deliver clear, bright high resolution photos and video! The 5” LCD monitor allows comfortable viewing, and intuitive, easy-to-use controls provide photo and video capture at the touch of a button! V2’s have a wide, 4-way articulation range, and are small, lightweight, and priced starting at only $8995. V2’s are available in both 4 and 6 mm diameters.

Optional 90° Prism and Close-Focus adapter tips.

Made in USA TRY

BEFORE YOU BUY!

gradientlens.com/V2 WINDPOWER ENGINEERING & DEVELOPMENT

Fire Prevention_6-17_Vs2 pd.indd 39

800.536.0790

39

6/8/17 11:47 AM

COND I T ION MONITORING

David Clark President CMS Wind

Stop ignoring the generator in your condition monitoring effort

T

hat thing in a wind turbine that actually makes electricity − how do you monitor its health to ensure it works for a long time? The more common practice of vibration analysis is somewhat limited when it comes to determining the health of a generator.

To understand or establish a condition monitoring approach, we should first understand the failure modes and root causes to those failures.

About 50% of drivetrain failures are in the generator with annual failure rates ranging from 5% up to 15% with an average around 10 to 11%. This is based upon 10 GW’s of vibration analysis.

Up-tower repairs average $5,000 to $6,000 for a generatorbearing change out and $80,000 to $90,000 for an unpredicted failure that requires a crane.

The wide price differences show that predicting failures has a tremendous return per event.

The failures are centered on the generator bearing and are rooted in three major factors that account for 66% of the generator failures. These are easily seen in vibration analysis and include:

tests of generator health? Suppliers for specific electrical test equipment can provide diagnostic systems. These are not the multi-meters you find in the big-box hardware stores.

In speaking with two major wind-industry focused, generator rebuilders, the hands down leading cause of electrical failure is a short-to-ground somewhere within the generator. In fact, the Electro Mechanical Authority (EASA) suggests tests for such a

• Lack of lubrication • Misalignment • Electrical discharge and fluting But electrically speaking, how do generators fail? Failures at the ground wall (windings to the generator frame insulation) are one source and failures between the windings (turn-to-turn insulation) is another.

So how do you test for electrical resistance, partial discharge, surge test, and other indicative 4 0 WINDPOWER ENGINEERING & DEVELOPMENT

Condition Monitoring_6-17_Vs2 pd.indd 40

A stepped-voltage surge test is plotted by the green line in the graph. The partial discharge of voltage is shown in the vertical graph bars as the voltage is increased.

Partial discharge of voltage has been measured as part of maintenance programs only in the past 15 years while test technology has made significant progress in the past 5 years.

Image courtesy of Schleich.

www.windpowerengineering.com

JUNE 2017

6/8/17 11:51 AM

CONDITION MONITORING

Electric motor failures mirror those of wind turbine generators.

fault at two to three-month intervals. These tests, however, are rarely if ever performed in the wind industry. Having used these testers myself, I can say the total test time is less than 15 minutes.

There are many electrical tests not widely used on wind turbine generators and pad-mount transformers. The following are standard tests suggested by either EASA or IEEE (Institute of Electrical and Electronics Engineers) or both.

Visit either website and you will find recommended practices and standards.

EASA’s AR100-2015 Recommended Practice, outlines several tests in Section 4 that range from Phase Balance to High Potential (hipot). The point of these tests is to determine the health of the generator insulation and its internal windings. A few other tests include a: Resistance test which looks for an interruption in the windings through a resistance measurement. This test takes one minute. High readings indicate a resistance that should not be there, which signals an issue.

Polarization index test includes a one minute and a 10-minute test. Others can use a 30:60-second test. The tests look for JUNE 2017

Condition Monitoring_6-17_Vs2 pd.indd 41

an insulation issue between the windings and the frame. It is useful in determining the insulation condition. Degradations are determined and ranked based upon the 1 to 10-minute test as well as a comparison of the previous measurements. In some cases, the degradation can be fairly long in lead time.

Winding surge test is a high voltage, short-term test using a voltage of twice the circuit rating plus 1,000 volts. The purpose of the test is to determine voltage leakage. One manufacturer’s tester has the ability to perform a partial discharge as a secondary test.

Several additional tests are not as widely used in the field and are more like QC measures. These include: • • • •

useful indicating something significantly wrong in installation, alignment, or balance. Still, a little benchmarking is more helpful than none at all.

Resources for generator acceptance by either an owner or OEM can be found in the EASA Standard AR100-2015 which is a good place to start. This is recognized as an ANSI standard. Other standards for repair include mechanical repair, rewinding testing, lubrication, and even shaft runout. Secondly, similar resources can be found through NETA or IEEE. Using these best practices and standards, a wind-farm owner can develop and acceptance program for rebuilt generators, a field test for condition monitoring and predictive maintenance, as well as commissioning and end-of-warranty (EOW) information.

The added effort and attention in this area offers large payoffs. In this age of performance data mining and minor incremental fleet improvements, the basics are sometimes overshadowed. Someone should be looking at the thing that makes the electricity. W A missing wedge at the top has caused a coil failure in a wind turbine generator.

Image: Success by Design.

Impedance test (coil comparison) Polarity test (individual phase comparison) Phase balance test (compares phases to each other) No-load test (could test current, magnitude, and balance)

Of course, there are also standards for balancing, vibration, and lubrication.

The vibration is really not all that useful in the existing recommendations. It is windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT

41

6/8/17 11:51 AM

S O F T WA R E Chris Shroyer CEO EdgeData

An EdgeData tech preps a UAV for a blade inspection.

Expect actionable intelligence from drone inspections operators. By cultivating partnerships with industry leaders, we’re training the next generation of inspectors to capture data so it provides actionable information.

T

he concept of big data was once thought to be a route to improving wind turbine inspections.

Somehow, more data would provide deeper insight to turbine conditions. Then came high-quality images and meta-data from aerial blade inspections.

Instead of big data, actionable intelligence is the preferred result of unmanned aerial systems (UAS) or drone wind turbine inspections. More recent advances, such as “deep learning” technology lets computers recognizes damage, pinpointing exact areas that need attention.

In addition, with time, patent-pending analytic software can track trends in wear and damage, and help operators determine proactive plans to maximize infrastructure lifecycles and deliver areturn on repair investments.

The three process pillars we have found most useful are Capture, Compute, and Consume. These and more have come from collaborating with wind farm owners and

42

WINDPOWER ENGINEERING & DEVELOPMENT

Software_6-17_Vs3.indd 42

Capture Turbine inspections by drones or UAS are still new, but dedicated groups are forming standards for flight procedures.

Earlier this year, we participated in developing flight operations procedures and processes for flying near wind infrastructures. Interested readers may find this useful: An Early Survey of Best Practices for the Use of Small Unmanned Aerial Systems by the Electric Utility Industry. It appeared in a publication from Oak Ridge National Lab’s publication. It’s here http://tinyurl.com/ small-unmanned-aerial.

One program intended for use in the field, the BladeEdge Capture Assistance Tool, ensures that every drone captures quality images. It also packages the images for processing by deep learning algorithms. This is a step toward automated flight assistance.

The future of UAS flights is being shaped by efforts of the faculty at North

www.windpowerengineering.com

JUNE 2017

6/8/17 1:10 PM

SOFTWARE

The UAV carries a high resolution digital camera and is guided around the blades by the pilot.

Dakota’s Lake Region State College (LRSC). Their Wind Technician Program now includes UAS curriculum in which students work towards remote pilot certification under FAA regulations Part 107.

They’ll train on the capture assistance tool and best practices for flight procedures that we helped develop. Students at the College will graduate primed for wind industry jobs.

Compute With LRSC training new wind technicians and a network of capable partners, we can focus on our core competencies of software, big data, and deep learning technology. Each time a UAS collects data, the patent-pending BladeEdge Analytics further trains the software to recognize damage and wear.

But not all flying conditions are created equal. In a perfect world, UAS inspections would be conducted on bright, sunny days. Of course, the weather doesn’t always cooperate.

One useful software development is a tolerance for poor conditions, so operators will always leave the field with the data they need.

To store all the data collected, a 16,000-square-foot data center is being built at Grand Sky, a UAS Business and Aviation Park in Grand Forks, North Dakota.

The highly secure facility will let us host an optimized environment for operations applications such as BladeEdge.

JUNE 2017

Software_6-17_Vs3.indd 43

Consume For the wind industry, this means operators will have access to better data and complete blade imaging.

They’ll be able to make educated decisions for proactive maintenance and damage repair – maximizing energy output (AEP) while negating potential losses.

This method focuses on delivering cost-effective and scalable solutions through partnerships that serve the entire industry. Years of compiled data will allow making a longitudinal comparison of damages. Trends will show how blades degrade over time. When raw data is turned into actionable intelligence, there’s no telling what improvements will be made. What is sure, the industry will be improved through the programmatic use of currently available technologies. W

The output screen comes from EdgeData. Damage is identified and recorded along with other photos from the same turbine.

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT

43

6/8/17 1:10 PM

T UR BI NE OF T HE M O NTH

Paul Dvorak Editorial Director Windpower Engineering & Development

Vestas quad experimental demonstrator

F

inally, a company has broken the tradition of one axis, one rotor, on one tower. Bigger and more reliable is probably the way of the future, but it is good to see a company experiment with a utility-scale turbine that is a little different. In this case, it is the novel Vestas four-rotor turbine and for the lack of a catchier name, we’ll call it the 4V29. For its financial guts and technical chops to

lightweight mount that can reduce mass and loads.

The prototype’s maximum tip height of 74m is notably shorter than many of today’s turbines but it meets Risø’s (the national testing lab in Denmark) building height restriction of 75m.

A LiDAR wind sensor at the tower top measures the wind field in front of the rotors. Also, when controls detect wind shear, different directions at

build something different, and not just in a computer simulation, we nominate Danish wind-turbine manufacturer’s quad as the Turbine of the month.

Vestas is not the first to design a large multirotor system, but to our knowledge, it is the first to build one. The 4V29 demonstrator uses four refurbished V29-225 kW nacelles, a model which the company produced from 1990 to 1997.

Rotor arms that hold each nacelle are braced with steel tension cables that offer a flexible,

To see the tower and support arm under construction, watch the video here: http://tinyurl.com/4V29underconstruction

4 4 WINDPOWER ENGINEERING & DEVELOPMENT

TOTM 2-17 Vs 3 pd.indd 44

www.windpowerengineering.com

JUNE 2017

6/8/17 11:55 AM

TURBINE OF THE MONTH

different altitude, the turbines can respond accordingly. In a conventional turbine with a 100m rotor, its response is a compromise, which tends to stress the blades.

Goals of the experiment are to learn more about solving aerodynamic, transport, and structural problems of huge conventional turbines. For instance, rotors spinning within 1.5m of each other could uncover surprises.

Transporting large turbines on land is getting more challenging. Shipping smaller 4V29 components would overcome some of the problems. And lastly, the tower may reveal unexpected structural vibrations.

“The ultimate goal is to assess if we can build an even more cost-efficient turbine by challenging the scaling rules,” said Jorge Magalhaes, Senior VP, Vestas Innovation & Concepts, in a press statement.

Although the Danes are good engineers, they have selected a control system that uses the U.S. Department of Energy’s Wind Program and control software developed by engineers at Sandia National Laboratories. Dr. Jon White leads Sandia’s Wind Plant Optimization Team and explains that the lab created

White says the hardware-in-theloop system consists of a:

The finished experiment at the Risø test site looks like this.

• Control computer and turbine software replica, • Computer emulating inputs to the sensor and feeding them to the control computer, and • Scaled-down generator that emulates the turbine’s drivetrain and wind loading.

This system lets developers test and configure the controllers to meet standard wind-industry procedures before Vestas is not the first to design a installation. large multi-rotor system, but to our The Vestas prototype, a knowledge, it is the first to build one. not-for-sale demonstrator, a hardware-in-the-loop system and an has finished construction and is now open-source rapidly reconfigurable control in operation at the Risø test site near environment to test and deploy innovative Roskilde, Denmark. Several good technology at the Lab’s Scaled Wind Farm videos are online. One is here: http:// Technology facility in Texas. tinyurl.com/vestas4V29 W JUNE 2017

TOTM 2-17 Vs 3 pd.indd 45

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT

45

6/8/17 11:56 AM

Why lubricant formulation oil analysis matters

&

for wind-turbine gearboxes

Michelle Froese • Senior Editor • Windpower Engineering & Development

There are few other industries where demands on the gears and bearings are as high as in the wind-power sector. For example, gears in turbines transmit torques of up to 5 MNm, and often in harsh and variable conditions. The components are exposed to all kinds of environmental influences, which means lubricants must be made to offer high-wear protection, lower changes in viscosity at rising or falling temperatures, resistance to oxidation, and provide good loadcarrying capacity. Photo: Klüber Lubrication

4 6 WINDPOWER ENGINEERING & DEVELOPMENT

Feat_OandM_6-17_Vs4.indd 46

www.windpowerengineering.com

JUNE 2017

6/8/17 11:58 AM

FOR MAXIMUM PERFORMANCE, a gearbox lubricant must be correctly specified for a wind-turbine’s operating conditions and carefully monitored. A poor lube choice or ignoring oil cleanliness means a turbine’s gearbox will fail to function properly or with much longevity.

Certainly, quality counts, but a healthy, well-lubricated turbine combines high-performance and wear tolerance with well-timed service checks and oil analysis.

How to make a wise choice As engineers strive to improve the efficiency and output of larger turbines, their lubricants must function at even higher operating loads.

Such products must also do so while reducing temperatures in a turbine’s gearbox. It’s a tough job and one that warrants a thoughtful choice.

Although use of synthetic oils is now more typical than mineralbased options in the wind industry, this only puts a small dent in the available choices manufacturers and turbine operators must consider.

According to a recent white paper by lubricant specialists, Klüber Lubrication, many basic synthetic oils no longer meet the tough requirements of the wind industry and, as a result, operators are turning with increasing frequency to new, higher performance synthetic oils. The paper entitled, Wind Turbines Power Up with Oil, maintains that lubricant manufacturers are increasingly responding with specialty products that meet and even exceed the standards set before them.

“Many of new lubricants offer high-thermal resistance, resistance to oxidation, a more consistent viscosity, good load-carrying capacity and high wear protection for bearings and gears, and low residue formation,” says a spokesperson for Klüber. However, users still have to know what to look for based on the characteristics of their wind farm because different base oils, such as polyalphaolefin, polyglycol, or rapidly biodegradable ester, are used to formulate these gear oils.

“Developing these lubricants requires knowledge of additives — their chemistry, which additives to use, what combinations to use them in — and of base oils. The purer the molecular structure of the base oil, the better the lubricant,” the white paper reads.

JUNE 2017

Feat_OandM_6-17_Vs4.indd 47

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT

47

6/8/17 11:58 AM

Why lubricant formulation oil analysis matters

&

for wind -turbine gearboxes

By coupling a fully equipped LaserNet 230 with ferrous capability to an automatic sample processor (ASP), a full tray of 24 heavy (320 cst) wind-turbine gear oil samples can be analyzed in ~2.5 hours. This can all be accomplished with no operator intervention and can yield: Particle distribution >4um (ISO 4,6,14 Codes), wear shape classification and distribution >20um (p/ml), percentage of large ferrous >20um (p/ml), and total ferrous (ppm).

Like the conventional synthetic oils that preceded many of these newer products, highperformance synthetics are subject to the tests of OEMs and must meet a number of global standards. For example, industrial gear oils are classified in accordance with DIN 51 517. Part 3 of this standard defines the requirements for gear oils that are exposed to high loads.

“Because gear oils should also be suitable for lubricating the rolling bearings in a gearbox, the standard DIN 51 517, Part 3, also contains the FE 8 rolling bearing test rig,” says Klüber. The FAG FE 8 test rig, developed by the rolling bearing manufacturer FAG, is used to assess the antiwear properties of an oil and its effect on the rolling bearing service life. “In this test, the wear of the rolling elements should not exceed 30 mg.”

The assessment of gear oil performance for wind turbines also includes tests that measure scuffing load resistance and micro-pitting resistance.

For example, a test developed by Intertek’s FZG, measures anti-wear properties of the lubricant at low gear speeds, as the planetary gear stage is run at the lowest speed. In this test, better performing lubricants fall within the low wear category.

Klüber further explains that gear efficiency is typically determined by the friction characteristics of

Gearbox designs contain more equipment to produce more work, and more work means the generation of more heat in the gearbox. As a result, lubricants must function at higher operating loads while helping to reduce temperatures in the gearbox.

4 8 WINDPOWER ENGINEERING & DEVELOPMENT

Feat_OandM_6-17_Vs4.indd 48

www.windpowerengineering.com

the lubricating oil. The friction coefficients of different base oils can be seen in the result of the FZG test rig. In fact, today’s gear oils can reduce temperatures by as much as 68°F, and lower the amount of lost power by as much as 18% when compared to standard gear oil.

Another important consideration: extended life and service intervals.

“The value placed on oil and lubricants in the wind industry has increased substantially in recent year because a high-performance product contributes to substantial long-term cost savings through better power transfer and component reliability,” the white paper reports. A quality product will typically result in longer oil-drain intervals, less waste, and more economic operations.

So what was once a commodity selected on the basis of price is now considered by many as a machine element, carefully specified in much the same way gears and other components are specified.

Planning O&M calls A high-performing lubricant is important but only one step toward reliable turbine operation. A careful and continuous condition-monitoring plan is also essential.

However, ever-changing winds, variable climates, and remote locations can impact service calls wind sites.

Friction values of various base oils determined on a double-disc test rig. (Test conditions: Hertz load PH=1,000 N/mm2, slip 20%).

JUNE 2017

6/8/17 11:58 AM

FROM IMPROVING TURBINE EFFICIENCY TO POWERING NATIONS TOGETHER IT’S POSSIBLE Keeping wind turbines working efficiently and reducing operating costs can be critical for a profitable business.

At Shell Lubricants, we appreciate that turbines operate in tough conditions, and that, to be competitive, you need them to be reliable and have high availability. Our advanced technology wind turbine lubricants are designed to help you to n

extend oil and grease life

n

extend your equipment lifetime

n

improve your system efficiency and energy yields

thereby supporting your efforts to reduce your total cost of ownership.

To find out how we can help you power tomorrow, go to shell.com/lubricants

SHELL LUBRICANTS TOGETHER ANYTHING IS POSSIBLE

228640_wind power_advert_fullpage_v02.indd 1 Shell_6-17.indd 29

04/05/2017 10:38 6/8/17 10:19 AM

Why lubricant formulation oil analysis matters

&

for wind -turbine gearboxes

The ASP and LaserNet 230 ferrous combination is an ideal screening solution for wind-turbine gearbox applications where sample volumes are high. The system can accurately identify problem samples from a trend based on particle size distributions. The source of the wear can then be identified using the shape classifier and the ferrous information.

Many wind-farm operators rely on conditionmonitoring systems to alert them to real or anticipated maintenance issues.

“Automated monitoring of these critical and expensive assets is key in the wind industry,” says Tom Barraclough, Product Engineering Manager at Spectro Scientific, one of the largest industry suppliers of oil and fluid analysis instruments. “Even with the best lubricant, wear particles will eventually build up if not properly monitored.”

While there are fairly reliable and non-invasive indicators of overall oil and machinery health, he says there are no substitutes for specialized lab tests, particularly when analyzing numerous samples.

“Online techniques are available as site solutions for customers with multiple wind farms, but these are typically costly and not sensitive enough for in-depth oil analysis of multiple turbines. Centralized testing analysis — so by sending samples to a regional service center — tends to offer the best cost-to-monitoring benefit when it involves large volumes of turbine samples.”

Barraclough points out that ferrography is still one of the leading root cause, oil-analysis techniques but it requires a complimentary screening

“It is extremely important that a more in-depth ferrography analysis be undertaken on any select samples that show abnormal ferrous readings.” Barraclough explains that abnormal wear generated in a gear system typically comes at the pitch line of the gear tooth (fatigue) or the tip of the gear (severe sliding). “At the pitch line, the contact is rolling so the particles will be similar to rolling contact fatigue particles. The gear contact has an increased sliding component as the root or tip is approached and, over time, the particles will show signs of sliding morphology.”

This morphological wear data is actually beneficial to end users or wind operators because it demonstrates a baseline trend. “By running oil samples in the exact same mechanical manner over and over the repeatability from sample to sample is excellent, and any deviation in sample data from a well-established trend can easily be identified by an analyst.”

In other words, abnormalities in the gearboxes caused by large particle generation are easily identifiable when trends are established that can distinguish ferrous from non-ferrous material. But to run continuous oil samples and achieve reliable results, it is imperative to ensure samples are handled properly.

“In a typical batch of turbine gearbox samples, it is not uncommon to have very high levels of water or additive breakdown often being reported as >2 million particles, so it is important to use an imaging system that can easily handle contamination without issue. It is also important that a sample, or the next one tested, is not cross-contaminated.”

It is extremely important that a more in-depth ferrography analysis be undertaken on any select samples that show abnormal ferrous readings. method that closely links particle size distributions, morphology, and ferrous content. A ferrography test isolates wear debris and solid particulates for closer examination under a microscope.

50

WINDPOWER ENGINEERING & DEVELOPMENT

Feat_OandM_6-17_Vs4.indd 50

Barraclough says this is typically done with a specially developed dynamicflush sequence determined by continuous monitoring of the particle count as the flush is taking place. “For example, we’ve

www.windpowerengineering.com

JUNE 2017

6/8/17 11:58 AM

equipped our LaserNet 230 particle counter and ferrous debris monitor with an automatic sample processor.

A cleanliness threshold is set in the software and once the count gets below this value the flush stops and the sample progresses. This is important because a typical wind-turbine gearbox running on a relatively new oil may only contain 1300 to 10,000 p/ml or and ISO code from 18 to 20.”

What makes the automatic sample processor (ASP) unique is that it uses a stirring method, which is better suited for heavy gear oils than manually shaking it on a stand-alone system. “The particles in the sample are homogenized using a special stir motor which rotates at an optimally selected speed. The speed is selected so as not to introduce excessive bubbles into the sample,” he explains. “The stirring

creates a vortex effect in the oil that sucks the particles from the bottom of the bottle into the sample volume, creating a homogenized sample.”

Once the sample has been stirred, Barraclough says the contamination on the stirrer and sipper are cleaned using solvent spray jets in the wash tanks. The stirrer is then spin dried and ready for the next sample. The LaserNet can analyze and screen over 100 samples a day without dilution or sample preparation.

“The ASP and LaserNet 230 ferrous combination is an ideal screening system for wind-turbine gearbox applications where sample volumes are high,” he says. “The system can identify problem samples from a trend based on particle size distributions, and pinpoint the source of wear — which can lead to lower maintenance and longer-life turbines.” W

Compared to a conventional mineral oil, Klübersynth GEM 4 N shows reduced wear, temperature, and power loss in the FZG test.

JUNE 2017

Feat_OandM_6-17_Vs4.indd 51

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT

51

6/8/17 11:59 AM

&

new

technology

EAGLES BATS near wind farms

Previous attempts to guard avian wildlife from wind turbines have involved project cancellations or observers with

binoculars scanning the sky ready to report invaders. Good

news: This next generation of equipment aimed at eagles and bats is more vigilant and more reliable.

Paul Dvorak • Editor • Windpower Engineering & Development

IT’S NO SECRET THAT CRITICS of wind turbines use bird and bat takes as opportunity to curb the wind industry and slow its progress. The actual number of deaths due to turbine rotors are lower than what they would have you believe, but still serious enough to warrant research to bring the number to near zero.

Recent developments in the protection of avian wildlife are significant because of the reliability they bring to the effort. For example, previous efforts to reduce eagle 52

WINDPOWER ENGINEERING & DEVELOPMENT

Feat_Wildlife_6-17_Vs2 pd.indd 52

mishaps involved positioning people around a wind farm equipped with binoculars and radios, ready to spot potential intruders.

When an eagle was identified, its location would be radioed to a central command where a curtailment order would ideally shut down the turbine nearest the bird. If everyone is alert and communicating clearly, such a system might work. Radar systems have also been tested with mixed results.

While human spotters are still used at

a few sites, more reliable and always-alert systems are ready to improve on a strictly human effort. For example, one system aimed at protecting eagles can spot them a kilometer away from a wind turbine and make automated decisions. One promising system for bats signals them to think no food is near a particular turbine. So they look elsewhere.

Reasonable minds will applaud the following successes and encourage further development.

www.windpowerengineering.com

JUNE 2017

6/8/17 12:01 PM

Good news for eagles Eagles, condors, and other large birds will soon more safely fly the skies over wind farms, thanks to the development of IdentiFlight. The system, based on artificial intelligence (AI) and high-precision optics, can detect eagles up to one kilometer away and then track the bird’s speed and flight path. Should the data indicate a risk of collision with a rotor, the potentially harmful wind turbine or two can be shut down and restarted when the bird has left the area.

JUNE 2017

Feat_Wildlife_6-17_Vs2 pd.indd 53

Photo courtesy of istockphoto.com

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT  

53

6/8/17 12:01 PM

new

technology

&

EAGLES BATS

near wind farms

Automatic detection and species determination by the IdentiFlight system occurs in seconds. The system addresses the issue by blending AI with the high-precision optical technology developed by Boulder Imaging to detect eagles and protect them from harm.

We see you. Eagles and other large birds may find friendlier skies over wind farms when devices described here go into wider service.

It works like this: “A ring of eight stationary cameras with a wide field-of-view can detect enough pixels of an object flying up to 1,000m away,” says IdentiFlight President Tom Hiester. “They detect motion of the object with algorithms that decide whether or not it is important. It might be an eagle or something OK to ignore, as it would be for small aircraft. When

the system wants a closer look, high-resolution stereo cameras at the top level, on movable pan and tilt mechanisms, can take a closer look at the bird. Because they are stereoscopic, they can measure the distance and size of the bird. In fact, it makes about 200 measurements and analyzes 80 different attributes every 250 ms,” he says.

In addition to Golden and Bald Eagles, says Hiester, the technology can be extended for use in the protection of California condors and other species of concern.

How the units will be deployed depends on what the owner feels is necessary for their risk mitigation. “In high eagle-risk areas, the classification determination is made rapidly with overlapping sensors, which means several sensors in the wind farm. Depending on rotor diameter and topography, a single camera system can cover three to five turbines. On the other hand, some owners may want to keep watch on one isolated eagle nest and so would need just one system,” says Hiester.

IdentiFlight systems are operating in pilot programs at Wyoming and Minnesota wind farms with elevated eagle activity. “These include four units operating at Duke’s Top of the World wind farm, a 200-MW project near Casper, Wyoming. Graphic displays provide audible and visual alarms to people in operations so they can make further determinations. We are working to attach its data feeds to SCADA outputs,” he adds.

Hiester says that by the time you read this, he expects a third-party performance

WHITE-NOSE SYNDROME

NRG Systems has been working with Bat Conservation International (bci.org) to preserve bat populations.

Photo: Alan Hicks, New York Dept of Environment Conservation

5 4 WINDPOWER ENGINEERING & DEVELOPMENT

Feat_Wildlife_6-17_Vs2 pd.indd 54

Several bat populations, including Indiana bat, the little brown bat, and long eared bat have been falling because of the white-nose syndrome. “It is the main driver of their population decreases,” said Brogan Morten, Product Manager, NRG Systems. To make matters worse, the syndrome is spreading.

It’s a fungus that grows well in cool damp caves, places where some bat species hibernate over winter.

The fungus grows on the skin tissues of hibernating bats. It repeatedly rouses them from hibernation, causing them to consume their winter fat stores. Eventually, they starve to death before spring.

Once an infected bat enters a cave, it transmits the fungus to other bats and caves. “It is absolutely devastating to hibernacula like that in New England. Reductions of 80 to 90% have been reported. Bats produce only one to two pups a year making for a slow population recovery. So while turbines are not a primary cause of their declining numbers, taking more hurts their recovery efforts.” said Morten. www.windpowerengineering.com

JUNE 2017

6/8/17 12:02 PM

report on the accuracy and effectiveness of IdentiFlight from The Peregrine Fund and the American Wind and Wildlife Institute.

IdentiFlight International has purchased the assets of the IdentiFlight system, from Renewable Energy Systems Americas, a firm that provides construction and operations of wind, solar, transmission, and energy storage projects. IdentiFlight International is jointly owned by Boulder Imaging and private investors affiliated with the company.

Good news for bats Bat conservation is a tougher nut to crack because they are smaller animals than eagles. But they are worth protecting because they are voracious eaters of

Bat Deterrent System that uses a set of ultrasonic speakers to discourage bats from flying around operating wind turbines. The speakers produce ultrasonic sound in a

A ring of eight stationary cameras with a wide field-of-view can detect enough pixels of an object flying up to 1,000m away. range of frequencies that tend to negate the bat’s own signals, ultimately turning the bats away from the generated sound and the turbine rotors.

Brogan Morton, Senior Product Manager at NRG Systems, has been working with Bat Conservation International (BCI),

An IdentiFlight sensor on a tower includes a lower level of high-resolution cameras that look for birds in flight up to 1,000-m away. When the camera detects movement, the pan and tilt stereoscopic camera on the top level makes object measurements while algorithms calculate possible flight paths.

insects, including mosquitos and cropdestroying pests, and bats are avid pollinators.

Engineers at NRG Systems in Hinesburg, Vermont, have made significant headway in the area of bat conservation.

The company is currently developing a JUNE 2017

Feat_Wildlife_6-17_Vs2 pd.indd 55

a leading conservation group, to develop and promote this solution to bat takes at wind plants. NRG and BCI recently revealed thermal video taken at a pond test of the forthcoming Bat Deterrent Systems that provides compelling proof that the product could change the game for bat conservation windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT  

55

6/8/17 12:02 PM

new

technology

&

EAGLES BATS

near wind farms

in the wind industry. The video traces the bats’ flight paths at night over an insect-rich pond. The traced paths illustrate how the bats avoided the area in which their echolocation systems were jammed due to the Deterrents. When the devices were turned off, the bats quickly returned to protected areas of the pond, within 15 to 20 seconds.

Current bat protection strategies typically depended on wind turbine curtailments based on time of day and year. Although such schemes tended to reduce bat mortality, they sacrificed power production. What's more, recent wind turbines with larger rotors can be productive in low-wind speeds, from cut in at about 4 m/s through 6.9 m/s, which is about the wind speed limit in which bats can be active. Because they are small animals, bats tend to conserve their energy by not flying when the wind is stronger.

There are also temperature thresholds below which they are not very active.

“The problem is that power curves on a few newer turbines, such as the Vestas 2-MW platform, V116 and V120, and the Gamesa G116, are shifting to the left, meaning they are intended for lowerspeed wind sites. So the 6.9 mps becomes a significant production figure. The AEP numbers from farms with these turbines, where a lot of the development is now, would be reduced,” said Morton.

While turbines have been a problem for bats, a bigger concern for wildlife specialists has been White Nose Syndrome, a usually fatal bat disease. It has taken a heavy toll on several U.S. bat populations so conservationists are

The ultrasound does not harm them in any way. They don’t become disoriented or fly around in circles. They just leave. eager to preserve those unaffected while biologists look for a cure or the disease runs its course.

Until that time, Morton’s team will focus on keeping bats out of the high-risk areas, including the rotor circle.

“Bats use ultrasound to orient, forage, and hunt. They will send out a pulse that will bounce off of a moth or whatever insect they are chasing, and a faint signal will come back to 56

WINDPOWER ENGINEERING & DEVELOPMENT

Feat_Wildlife_6-17_Vs2 pd.indd 56

An IdentiFlight technician prepares a camera for deployment.

Eagles are the primary target of protection for the time being but the system could be tuned to identify larger condors.

them, allowing them to locate their prey.

Our Deterrent Systems generate an ambient ultrasound noise that masks the bat’s return.

Since it cannot find prey in that airspace, it doesn’t want to be there.”

Morton adds, “It’s important to note that there is no impact beyond the rotor swept area. We don't want to push bats out of their habitat. We just want to keep them away from the rotor. The ultrasound does not harm them in any way. They don't become disoriented or fly around in circles. They just leave.

And when the Deterrent is shut off, they return to the airspace in seconds.”

Furthermore, because Deterrent Systems emit ultrasound, there should be no siting impacts that might come from sounds audible to humans. The ultrasound it is above human audible frequencies and there has been no effect on birds thus far.

A single turbine would require about six Bat Deterrent Systems mounted to surround the rotor. "The whole system

www.windpowerengineering.com

JUNE 2017

6/8/17 12:02 PM

takes about 40W to power, and because they have no moving parts, would require no maintenance. We expect a working life of at least 10 years," said Morton.

NRG Systems has successfully completed initial testing and has begun the second phase of trials at four wind farms – three in the U.S. and one in Ontario, Canada. Morton says the Deterrents will be used at night.

During the day, techs will walk the areas around the turbines looking for takes. “This baseline data will tell us how significantly NRG’s Bat Deterrent Systems reduce takes versus normal operations,” said Morton. “It is important that we conduct tests in different areas of the world with different bat species.

For instance, Ontario is included in this next round of testing because it is home to affected species and has a different regulatory regime.”

“The ultimate goal is to become an avoidance device, which means we are equivalent to a 6.9 mps curtailment,” said Morton. The U.S. Fish and Wildlife Service will hopefully allow developers to avoid the take permitting process, which can be lengthy and resources intensive, if they install an ultrasonic acoustic deterrent that equals avoidance level minimization. W

FOR FURTHER READING Interested readers will find these additional articles on wildlife conservation useful.

New research aims to deter eagles from wind turbines tinyurl.com/eagle-research Wind energy industry announces new voluntary practices to reduce overall impacts on bats by 30% tinyurl.com/lower-bat-takes

Project update: How the wind industry is protecting bats tinyurl.com/protecting-bats Looking out for our avian neighbors tinyurl.com/avian-neighbors

The ultimate goal is to become an avoidance device, which means we are equivalent to a 6.9 mps curtailment.

The two NRG Systems ultrasonic transmitters are mounted atop a wind turbine nacelle. A blade is visible to the right.

JUNE 2017

Feat_Wildlife_6-17_Vs4.indd 57

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT

57

6/8/17 1:12 PM

wind industry trends

to help predict its future

wind industry trends

to help predict its future

EACH YEAR THE WINDPOWER ENGINEERING & DEVELOPMENT STAFF and its research department identifies the more significant trends that drive the wind industry. The effort is to answer the frequently asked big question: Where do we go from here?

This year, we think the big trends are those that drive gearbox reliability, blade maintenance, power storage, and condition monitoring. Of course, the effort is aimed at reducing costs, essential because the Production Tax Credit is stepping down. The IRS says that wind energy projects that begin construction this year will qualify for $0.0184/kWh produced.

Construction has set records for the first quarter of the year, and the pace may continue for a while, but that is not certain.

What is certain is that the PTC will expire completely by 2020. By then the critical mass of projects or the momentum of the wind industry will keep it going for the next few decades. After that, the crystal balls grow cloudy.

58

WINDPOWER ENGINEERING & DEVELOPMENT

Feat_TRENDS_6-17_Vs2.indd 58

• DRIVETRAIN RELIABILITY • POWER STORAGE • CONDITION MONITORING • TURBINE BLADE OPERATION & MAINTENANCE

www.windpowerengineering.com

JUNE 2017

6/8/17 12:06 PM

TRENDS IN GEARBOX RELIABILITY Like a marksman in a shooting gallery, the wind industry is scoring solid hits on most of the problems that have plagued wind-turbine drivetrains. A few significant developments include better bearing designs, understanding the metallurgy of gears, improved load sharing, and torque dampers to relieve drivetrains of shock loads. Even journal bearings are getting a fair hearing and showing great promise.

Several years ago, an engineer familiar with gearboxes traced out how many units a turbine would need before reaching the 20-year mark. His pencil marked about every third year to approximate the need for a replacement over a 20-year timeline . Most turbines worked without condition monitoring so predictive maintenance was unheard of. Up-tower repairs were just under consideration so the first thoughts were: How could anyone make money in this business?

Shortly thereafter, Moventas announced up-tower bearing replacements and that alone took a big bite out of costs. Condition monitoring with easy to read trend lines and alarm limits brought predictive maintenance to O&M operations. Improved oil monitors can now count the debris in the gearbox lubricant and add to the accuracy of predictive maintenance.

Fewer parts also took some of the failure modes out of gearboxes. For instance, machining an outer race into a planet gear removes the conventional and separate outer race, and allows using larger bearings with larger load-carrying capacities. If successful, journal bearings might take rolling element bearings out of planetary sections.

Also, hard bearing coatings are making races more resistant to spalling and shock loads. This is important because most gearbox problems originate

JUNE 2017

Feat_TRENDS_6-17_Vs2.indd 59

in the bearings. Once they begin to break and steel debris circulates in the oil supply, it gets distributed throughout the gearbox and encourages further wear. Timken provides what it calls a Diamond-like coating, while SKF has introduced black-oxide coatings for greater reliability.

Studying all this has led to a better understanding of how a wind-turbine bearing fails. Post mortems have shown that their failures began, apparently, with small inclusions just below the bearing surface. But bearing manufacturers have taken great care to machine races and rolling elements out of steel formulations

Lastly, dissipating the shock loads to a drivetrain through a torque damper has shown a good way to lengthen gearbox life. AeroTorque, the developer of one torque damper, says that units have been working successfully for about five years.

Sentient Science, a material science and predictive maintenance software developer, has predicted that recent improvements to a Moventas gearbox, many described above, will lead to a fourfold increase in working life. That means a gearbox that would need repairs every three or four years, might run 12 to 16 years without serious maintenance, and that would be remarkable. W

Studying all this has led to a better understanding of how a wind-turbine bearing fails. Post mortems have shown that their failures began, apparently, with small inclusions just below the bearing surface. that are cleaner than the steel used in most other industries. Where do the inclusions come from? Another mystery: Staining the areas around crack-initiation spots reveals white areas not visible in undamaged bearings. What's more, the material around the white-etched area is much harder and a different composition than the bearing steel.

Several theories provide explanations for this. One is that impact loading from torque reversals act like hard hits from a hammer to provide energy for the material transformation.

These developments have led material scientists to recognize that case-carburized gears last longer than the through-hardened variety. Case carburizing hardens just the surface of the gear or race, leaving the internal metal unhardened and possibly more flexible.

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT  

59

6/8/17 12:06 PM

wind industry trends

to help predict its future

TRENDS IN POWER STORAGE Renewable energy is by nature, variable. The wind does not always blow nor the sun shine. When the customers ask for power, it should be there. Few excuses are acceptable.

Uninterruptable power supplies (UPIs) were an early way to live with power shortages, especially sudden disruptions because power outrages are expensive and annoying. A paper

by Honeywell reported that in 2016, analysts at Information Technology Intelligence Consulting conducted a survey in which 98% of respondents said a single hour of downtime costs their organizations more than $100,000.

But several years ago at an AWEA conference, a presenter remarked that the economics of batteries or power storage to solve such production problems did not “pencil out,” or presumably provide an acceptable ROI. Times have changed.

News of power storage projects come on a daily basis and not just for the utilities. Batteries trends are reaching into homes,

The chart, from Mercom Capital Group, provides a look at the spending by venture capitalists. The numbers over the Q1 bars in each segment are the number of deal anticipated for the year.

60

WINDPOWER ENGINEERING & DEVELOPMENT

Feat_TRENDS_6-17_Vs2.indd 60

on micro-grids, and full-scale grids.

Power storage for the home has been made available from several companies. The most widely publicized comes from Elon Musk’s organization in the Tesla Powerwall. This home battery stores presumably solar generated power from a roof-mounted system also offered by Tesla. A single Powerwall provides 14 kWh of power, about 2 kW for seven hours for lights, sockets, and the fridge.

Utilities deal with other bigger problems. For them, storage is a way to solve overproduction, frequency regulation, and peak shaving.

The utilities know the power curve for their areas. It generally begins rising with sunrise and drops off at night, and the amplitude of that variation changes with the time of year.

Like a natural system, demand is always changing. Power storage is one way to accommodate the ups and downs of demand and possibly without spinning reserves.

Utility-scale trends, of course, lead to large batteries and more. Although lithium-based batteries dominate most storage systems, a variety of chemistries and even mechanical systems are being tried. Eos Energy Storage, for one, markets a zinc-based battery. One recent project involved 1,100 MWh of storage capacity, a figure greater than all commerciallydeployed battery storage in existence at the time, according to the company. Like others, the company builds large systems from basic units. For Eos, it is a 4-MWh unit. Another yardstick from the company is that it is taking orders at $95/ kWh, which continues the trend of lowering costs.

For comparison, Tesla’s Powerwall goes for $6,200, according to its website, or $443/kWh. So perhaps Eos is onto something. Another home based battery based power storage comes from Adara in a 20 kWh unit for $10,850, or $542/kWh before subsidies.

Another trend in the home market is the government subsidy. California residents, for instance, can take up to $6,800 off a system by applying for a state program. Other states offer similar subsidies.

Utilities also tend to partner with a battery company in addition to a controls company what will also provide an inverter, an electrical device that turns the ac grid power into dc that charges the battery and then when needed, reshapes the dc into ac for grid customers. An example of the arrangement involves utility American Electric Power and power-storage specialist Greensmith Energy. In a recent agreement, Greensmith provided a 14 MWh sodium Sulphur battery for frequency regulation on the PJM grid along with control software. W

www.windpowerengineering.com

JUNE 2017

6/8/17 12:07 PM

TRENDS IN CONDITION MONITORING Wind-farm owners and operators are continually looking for ways to optimize their assets use and maximize revenues. One idea is to invest in a system that monitors the health of turbine components and related electrical systems. While conventional condition monitoring is gaining wide acceptance, more recent systems take monitoring a step further to predict future maintenance issues.

This means site operators can conduct turbine repairs and replacements only when needed to avoid unnecessary and costly jobs up-tower.

Many wind operators have begun the move from condition-based monitoring systems, which include vibration sensors, to a more sciencebased prognostics approach. Advanced prognostic systems can predict failures before they occur letting maintenance managers plan ahead. In fact, a simple alert on a smart phone can now warn a wind-farm owner of a potential issue.

For example, consider GE Energy’s digital wind-farm apps for diagnostics and prognostics, which use operating, maintenance, and inspection data to project future operating conditions and predict turbine component reliability. GE says that by shifting from unplanned outages to predictive maintenance, the apps can help wind farm operators reduce maintenance costs by up to 10%.

Sentient Science’s Josh Fausset, Director of Customer Success, says condition monitoring and prognostics work well in many instances but not all. “For example, in gearbox bearings axial cracks, cage breaks, and gear-tooth damage are highly detectible. But early stage pitting from rolling contact fatigue tells another story.” He says many would argue that low-speed rotation (main bearing) vibration signals are often improperly instrumented or too weak to rely on for early detection.

“What operators have learned is that they need to take a comprehensive approach to failure planning and analysis. We cannot rely on one dataset, whether it be vibration, temperature, or lubricant characteristics, to tell a turbine’s full story,” he says.

To make this happen, operators and even OEMs have begun to digitalize their wind fleets and invest in software that lets them note but also compare data sets (think vibration, lubrication, SCADA, and accelerometer reports) on a common

JUNE 2017

Feat_TRENDS_6-17_Vs2.indd 61

Operators can rely on Sentient Science’s DigitalClone Live to better predict when turbine failures may occur, what critical components are at risk, and which life-extension actions will provide the greatest return on investment.

timeline of events. “This is no longer just about forecasting probabilities, but about understanding the actual wear that happens to turbines and related components over time,” says Fausset. “It is only by correlating data sets and recognizing patterns that preempt failure becomes possible along with a proper plan for long-term prevention.”

One trend that may make this easier is the Industrial Internet of Things (IIoT), a network that digitally connects devices. Craig VanWagner, Research & Development Engineer with Scada Solutions, says IIoT takes condition monitoring to a new level by letting machines swap information, such as wind forecasts and power demand. This means wind turbines can make decisions without human interaction, and react to conditions that might damage the unit, such as violent wind gusts or low lubricant levels.

“Previously, a developer would have to use a database or additional server to get multiple machines communicating. There had to be code in the system that somebody programmed to speak different protocols,” says VanWagner. “With the IIoT there is now a software module that makes it easy to share data,” he says.

Condition-monitoring data is clearly useful for wind farm owners to better maximize revenues and, now with the support of IIoT, wind turbines may also benefit from self-optimized uptime. W

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT

61

6/8/17 12:07 PM

wind industry trends

to help predict its future

TRENDS IN WIND-TURBINE BLADE O&M Wind-turbine blades are subjected to harsh weather and enormous external loads. Much of a blade’s longevity comes from good design and a lifelong O&M plan, which entails routine maintenance that checks for wear and damage. But as manufacturers and wind-farm operators are quickly learning, a blade’s ability to hold up over time begins at its design stage — and continues straight through until end-of-life.

Most modern blades are constructed from glass and carbon-fiber reinforced plastics that are flexible enough to shed strong gusts of wind without breaking.

According to global research facility, Fraunhofer, a single blade is made of up to 100 sheets of glass-fiber webbing that are layered, shaped, and then glued together with epoxy resin. Ideally, this is where the first quality checks should occur.

“The difficulty lies in layering the glass fiber sheets flat before they are glued, without creating undulations and folds, and avoiding the formation of lumps of resin or

sections of laminate which don’t set after applying the epoxy,” explained Fraunhofer’s Dr. Axel Hülsmann.

Thanks to research from Hülsmann and his team at Fraunhofer, these defects (as well as blade delaminations or fractures) can now be identified on a large-scale using infrared thermography.

At the center of the material scanner is a high-frequency radar system with specialized software that processes the signals and “visualizes” results. “Our material scanner allows identifying defects with even greater accuracy.

Depth resolution is also possible with radar technology,” says Hülsmann.

Once blades are in operation they face daily risks of damage (including cracks and leading-edge erosion) that, when left unchecked, lead to a degradation of performance and possible failure. Once wear is spotted, it is typically necessary to send an O&M team up-tower and down the blades for a manual inspection. This requires a SkySpecs’ autonomous drone inspections are making 15-minute wind-turbine blade inspections possible in many cases.

Photo courtesy of SkySpecs

62

WINDPOWER ENGINEERING & DEVELOPMENT

Feat_TRENDS_6-17_Vs2.indd 62

complete and costly turbine shutdown, and poses risk to workers at height. So some wind operators have looked to alternative inspection techniques.

For example, Cornis’ blade-inspection service uses a ground-based photographic scanning system that enables wind operators to inspect blades in less than two hours, even in cloudy or wind conditions.

The company reconstructs different 2D views of the blades on a “Google Mapslike interface,” with use of patent-pending algorithms to ensure image quality. The interface also stores a turbine’s history, facilitating further research.

“Unlike traditional techniques, such as rope access and crane operations, which require the direct intervention of third parties, clients can autonomously assess blade damage, say after a storm or lightning strike, and then decide if further action is necessary,” said a spokesperson for Cornis. “Blade inspection is made more frequent, reducing maintenance costs and risks.”

If extremely detailed, close-up shots are needed, unmanned aerial systems or drones are providing a newer alternative to blade inspections without risk to an up-tower crew. SkySpecs says it can offer automated drone inspections of turbine blade in less than 15 minutes, with as many as 17 turbines in one day. Their drones use an advanced damage-identification system to capture high-resolution images that identifies the blade damage. .

According to SkySpecs, blade inspections and report generations are completed in a fraction of the time it takes to conduct ground-based or rope inspections. “Smaller and more powerful computing platforms and sensors, better battery technology, and vastly improved algorithms for managing flight and safety have made drones an ideal tool for costeffective blade maintenance,” said Danny Ellis, CEO & Co-Founder, SkySpecs. W

www.windpowerengineering.com

JUNE 2017

6/8/17 12:07 PM

AD

INDEX

AeroTorque.........................................................................25 AMSOIL.............................................................................. IFC AWEA....................................................................................35 Aztec Bolting........................................... cover/corner, 29 Bachmann Electronic.....................................................IBC Castrol (BP Lubricants USA).............................................11 Dexmet Corporation..........................................................9 Gradient Lens Corporation.............................................39 Mattracks............................................................................... 2 Mobil SHC..........................................................................BC NRG Systems......................................................................27 Phoenix Contact.................................................................. 3 Shell Lubricants.................................................................49 Zero-Max, Inc..................................................................... 17

SALES

LEADERSHIP TEAM

Jim Powers 312.925.7793 jpowers@wtwhmedia.com @jpowers_media

Neel Gleason 312.882.9867 ngleason@wtwhmedia.com @wtwh_ngleason

Michelle Flando 440.381.9110 mflando@wtwhmedia.com @mflando

Tom Lazar 408.701.7944 wtlazar@wtwhmedia.com @wtwh_Tom

Jessica East 330.319.1253 jeast@wtwhmedia.com @wtwh_MsMedia

Garrett Cona 213.219.5663 gcona@wtwhmedia.com @wtwh_gcona

VP of Sales Mike Emich 508.446.1823 memich@wtwhmedia.com @wtwh_memich

EVP Marshall Matheson 805.895.3609 mmatheson@wtwhmedia.com @mmatheson

Managing Director Scott McCafferty 310.279.3844 smccafferty@wtwhmedia.com @SMMcCafferty

Associate Publisher Courtney Seel cseel@wtwhmedia.com 440.523.1685 @wtwh_CSeel

CONNECT WITH US! NEW

CHECK US OUT ON ISSUU!

JUNE 2017

Ad Index_6-17_Vs2.indd 63

windpowerengineering.com

WINDPOWER ENGINEERING & DEVELOPMENT  

63

6/8/17 3:22 PM

The world’s first wind turbines that boast of built-in hydroelectric capability WIND TURBINES ARE DESIGNED to generate energy, not store it. When winds are sufficient, the power goes straight to the transmission grid. But if the grid gets more energy than it can handle, electricity prices drop and turbines are shut down. The reverse is also an issue. When winds are low, turbines earn little to nothing.

Energy storage systems are one answer to the variability challenge of windgenerated power. However, most battery-based systems are still too costly to combine with most wind farms. So engineers in Europe have been busy thinking outside the box and inside the turbine tower. Their idea is to have towers on tall bases that serve as power-storage devices, holding water for hydroelectric generation. When power is in surplus, water is pumped into the base or a nearby reservoir. When winds slow or stop, the water is discharged through a hydro-turbine.

A four-turbine pilot project with integrated hydropower is in the works, thanks to a collaboration between German firm Max Boegl Wind AG and GE Renewable Energy. It is the first of its kind, located in Germany’s Swabian-Franconian Forest.

Engineers say it will connect to the transmission grid by the end of 2017, with the hydropower plant operational by the end of 2018. According to a release by GE: “The project creates an affordable way to store excess energy in a natural reservoir, and integrates the source and storage into one system.”

But there is a catch. For the system to work, location is key. Turbines must sit atop a hill with a lake or reservoir below to store water. For the pilot project, a man-made lake is situated 600 ft below the wind farm.

The plant itself will work much like a hydro-pump station. Water flowing downhill from the reservoirs will supply additional power to the hydro plant when electricity is needed. Conversely, when the energy supply is high, the hydro plant can pump water back uphill to the reservoirs. In this manner, GE says the system acts like a “giant battery.” Wind and water will work together to ensure efficient electrical output from the plant.

What’s more, this wind farm will feature GE’s 3.4-MW turbines with 440-ft diameter rotors. The 131-ft tall base will double as a water reservoir and can hold up to 1.6 million gallons. It further adds to the tower height, so the rotors will sweep up to 807 ft. The wind turbines for the project will also sit in reservoirs that can hold nine million gallons of water. At full capacity, the wind farm should produce 13.6 MW, along with another 16 MW from the hydroelectric capability.

Along with the wind turbines, GE is supplying the management software, which is intended to make the plant run more efficiently. The company’s Digital Wind Farm suite can collect and analyze data from different sources, such as the turbines and grid, to maximize power production.

If all goes well, Boegl says it expects to build one or two similar projects a year in Germany after 2018. W

6 4 WINDPOWER ENGINEERING & DEVELOPMENT

Downwind 2-17_Vs2.indd 64

The pilot project in Germany’s Swabian-Franconian Forest will feature wind turbines mounted on bases that will serve as water reservoirs, effectively increasing tower height by 131 ft for a peak rotor reach of 807 ft above ground.

(Photo: GE Renewable Energy)

www.windpowerengineering.com

JUNE 2017

6/8/17 12:08 PM

YOUR TURBINES ARE TALKING, ARE YOU LISTENING? OVER 6,000 BACHMANN CONDITION MONITORING SYSTEMS INSTALLED IN WIND TURBINES GLOBALLY. • Round-the-clock turbine diagnostics for any turbine • Bachmann Monitoring customer promise: Highest availability with unparalleled detection capabilities • Stand-alone and fully integrated CMS options available • Comprehensive CMS solutions tailored to your fleet: - Hardware – Software – Worldwide Monitoring - Installation – Training – Portable CMS Inspections

CMS solutions from the most trusted name in wind

Contact us: Bachmann electronic Corp.

529 Main St. Suite 125 Charlestown, MA 02129 Tel: 617-580-3301 email: office.boston@bachmann.info cms.bachmann.info

Bachmann_6-17.indd 29

6/8/17 10:14 AM

T:9” S:8”

The best view you don’t need to see.

Backed by an industry-leading seven-year warranty, Mobil SHC Gear 320 WT wind turbine oil is formulated to minimize downtime and maintenance, even in extreme conditions and temperatures. Find out how it can energize your business at mobil.com/wind ™

S:10”

Exxon Mobil_6-17.indd 29

6/8/17 10:16 AM

T:10.875”

© 2017 ExxonMobil. All trademarks used herein are trademarks or registered trademarks of Exxon Mobil Corporation or one of its subsidiaries.