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The technical resource for wind profitability







WINDWATCH: Powering wind forward at Windpower 2018


ne sio Te n d in W s New

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(R.E. Cantley Formula, Timken Corp: Circa 1977) 2.5

Relative Bearing Life



70 ppm avg. (Castrol CT 320 in-service data) 92 ppm avg. (nearest competitor published data)


198 ppm (nearest competitor in-service data) 0.5











Water (ppm)

*WEU Operations and Maintenance Report 2016. **Based on sample data available to Castrol.


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AGAINST BEARING WEAR Bearing failures are the most important issue in wind turbine gearbox maintenance, accounting for 70% of gearbox failures*. Castrol® Optigear® Synthetic CT 320 retains half the water PPM on average than our nearest competitor using similar types of chemistry. By choosing Castrol Optigear you can increase your bearing life by 50% and win the bearing life battle**. If you want to get the lowest water content in the field opt for Castrol Optigear Synthetic CT 320.

For more information go to or call 1-630-961-6562




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WIND ENERGY SOLUTIONS to keep your systems turning.

With a strong nationwide presence and over 50,000 system installations, HYDAC stands out as a leader in the Wind market. Our dedicated Wind field sales and service team is supported by a network of experienced engineers to meet any and all challenges, from new designs and solutions to upgrades and retrofits. Multiple USA-based manufacturing facilities provide our customers the flexibility to meet immediate needs and the ease to develop and implement solutions.

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• BN4HX Filter Element – Designed for heavy duty wind environment and long maintenance intervals • Filter Housings, NF (simplex) – A two-stage (course/fine filtration) design with integral bypass protection • GW Sensor – Placed in the filter housing for more precise measurement, it sends a signal if the element is suddenly retaining increased material • AS1000 Aqua Sensor – Reads humidity level in the gearbox and can set a parameter to send a signal when high • EY1356 Switch Sensor – A magnet collects material and closes the loop sending a warning signal of a possible issue • Split Housing Uptower Cooler (UTC Series) – Eliminates the need for a costly external crane, saving time and money • HYROFLEX Cable Clamps – Part of a system of various mounting supports for securing power cables in wind turbines. Two styles available half moon and star. | HYD1712-1950

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Senior Editor | Windpower Engineering & Development


Wind makes a good neighbor


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

American Society of Business Publication Editors

2017 National


Revenue of $3 million or under

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

American Society of Business Publication Editors

2017 Regional


Revenue of $3 million or under

APRIL 2018

Editorial_4-18_Vs2.indd 3

ast year, my good friend Anna spent the summer in a small, rural Ontario Airbnb. She was unaware when booking the home that it was near a wind farm, and was concerned initially about noise and shadow flicker. Neither affected her and it turned out that she loved seeing the nearby wind turbines. Anna told me the tall, windgenerating towers became a daily reminder for her of the environment and doing her part to preserve and keep it clean. “My grandmother used to tell me that the earth is something we all share in common, so I’d best take care of it,” she said. “Sometimes it’s good to get a reminder.” For Anna, a few spinning turbines prompted her to evaluate and streamline her own ecological footprint. She’s also become a serious wind advocate. As it turns out Anna’s positive attitude toward wind energy is one held by a majority of homeowners living near turbines in the U.S. Statistics show that over 1.3 million homes in America are within five miles of a large wind turbine. Until recently, the U.S. wind industry lacked a comprehensive understanding of the attitudes of those who lived near turbines. So in 2015, Lawrence Berkeley National Laboratory began a four-year, large-scale data collection project of individual attitudes of those living near wind farms, funded by the U.S. Department of Energy. Three years into the research, preliminary analysis finds that a large majority of individuals within five miles, and even within half-a-mile, have positive attitudes toward the turbines in their community. In fact, more than 9 in 10 people who live close to wind turbines view them positively or neutrally. What’s more, the Berkeley-led study is also examining individual perceptions of “wind-turbine sounds, shadow flicker, lighting and landscape changes; and participation in and perceived fairness of the wind-power project’s planning and siting process.”

This is important for two reasons. Feedback is essential if the wind industry is going to continually build the highest quality and safest wind farms possible. Secondly, it takes multiple partnerships and communities to maintain a successful industry — and that starts with open and honest lines of communication. According to a 2017 wind study by Ontariobased Western University, the more a community is aware of a project’s benefits and involved in the planning process, the more likely it is that a proposed wind farm will gain local support. Similarly, when Berkeley Lab respondents were asked for their opinion on fairness relating to wind project planning, developer transparency and openness ranked high. Interestingly, compensation (such as discounts on energy bills) is not an indicator of perceived planning process fairness. “The ability of the community or individual to influence the outcome of the project (for example, the number or location of the wind turbines) is also significantly related to beliefs about planning process fairness.” This is according to a summary of the preliminary analysis found at WindNeighbors. While there’s another year to go before the final analysis is complete, the data is providing valuable insight for developers. It is particularly relevant as the offshore wind industry launches in the U.S., and may serve to mitigate unnecessary project delays or disappointments (think Cape Wind). As Anna’s grandmother once pointed out we all share the earth, so ideally we should all get a voice on how we maintain it. I also think wind turbines are a fine reminder to all live more sustainably. W



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MARTIN ARMSON heads up the U.S. operations for Hansford Sensors, based in one of the fastest growing states: South Carolina. Armson, a mechanical engineer, first became involved in the vibration monitoring industry in the 1980’s. Since then, Armson has worked with several leading companies before joining Hansford Sensors in 2017. BRIAN BURKS, CLS, OMA 1, a Senior Application Sales Engineer at AMSOIL, bridges the gap between customers and AMSOIL engineers. With a focus on education, Burks brings a wide body of knowledge and expertise to his customers, working with them to shape maintenance plans and best practices. Prior to joining the AMSOIL team, Burks worked as a wind farm operator for many years. SCOTT EATHERTON, President of Wind Driven LLC, joined the wind industry in 1984 and has been a part of its advancement ever since. His work includes almost a decade representing wind-turbine owners and operators, and as a member of the AGMA 6006 committee that published the world’s first wind-turbine gearbox design standard in 2003. Eatherton has worn many hats in the wind business including managing sites, gearbox rebuild shops, turbine installations, warranty sweeps, technical training, quality control, due diligence. and failure analysis. ANDREW FILAK is a Principal with AMFConcepts in Redondo Beach, California. Filak was the formwork contractor for a number of conventional concrete structure, such as airport garages and of late has been developing ideas for advanced floating and fixed windturbine foundations made of polymer concrete. He and his team have also developed ideas for barges, construction methods for their structures, and ways to deploy them that takes significant cost out of conventional methods. Filak is a graduate of The Ohio State University.

JAKE GENTLE is a senior power systems engineer for Idaho National Laboratory, and the INL’s relationship manager to the U.S. Department of Energy’s (DOE) Wind Energy Technologies Office. As a program and project manager, he develops technology and provides technical oversight by coordinating solutions for the DOE’s Office of Energy Efficiency and Renewable Energy, the Office of Electricity Delivery and Energy Reliability, Department of Homeland Security, Department of Defense and various electric power industry partners. Gentle also leads the GMLC project, Operational and Strategic Implementation of Dynamic Line Rating for Optimized Wind Energy Generation Integration. He holds a Master degree in Measurement & Controls Engineering and a Bachelor degree in Electrical Engineering from Idaho State University. JESSE SHEARER, a Slip Ring Engineering Supervisor at United Equipment Accessories, is a 10-year veteran of the wind power and slip ring industries. His main focus is on hub slip-ring technology in large wind turbines. NICHOLAS WATERS earned a Bachelor’s degree in Applied Mathematics from the University of California, Davis and a Master’s degree in Ocean Engineering from Florida Atlantic University. His diverse background ranges from R&D at the small business level, to Structural Health Monitoring within the defense contractor space. Water is the Key Account Manager for Bachmann electronic’s North American office, and serves the wind industry by promoting products centered around open data access for owners. He works closely with sites to understand and solve unique challenges. He also advocates for predictive maintenance strategies within North, South, and Central American markets. KEVIN WOLFE assisted forming Wind Harvest International in 2006 and has been a board officer since. Now as Chief Operating Officer he is responsible for planning and supervision in engineering, manufacturing, certification, sales, marketing and R&D of the G168 VAWT Systems.












Contributors 4-18_ Vs2 pd.indd 4

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Editorial Director Paul Dvorak @windpower_eng

Web Development Manager B. David Miyares @wtwh_webdave

Videographer Manager John Hansel @wtwh_jhansel

Senior Editor Michelle Froese @WPE_Michelle

Digital Media Manager Patrick Curran @wtwhseopatrick

Videographer Bradley Voyten

Associate Publisher Courtney Seel 440.523.1685 @wtwh_CSeel

Videographer Derek Little @wtwh_derek


DESIGN & PRODUCTION SERVICES VP of Creative Services Mark Rook @wtwh_graphics Art Director Matthew Claney @wtwh_designer Graphic Designer Allison Washko @wtwh_allison

Production Associate Tracy Powers



Digital Marketing Director Virginia Goulding @wtwh_virginia


Manager Webinars Lisa Rosen @wtwh_lisa

Customer Service Representative JoAnn Martin

Digital Marketing Specialist Taylor Meade @wtwh_taylor

Customer Service Representative Stephanie Hulett

Events Manager Jennifer Kolasky @wtwh_jen

Customer Service Representative Julie Ritchie

Events Marketing Specialist Christina Lograsso @wtwh_christina

Digital Production Specialist Reggie Hall

FINANCE Controller Brian Korsberg

Director, Audience Development Bruce Sprague

Accounts Receivable Specialist Jamila Milton

2014 Winner

2011 - 2017

2013 - 2016 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© 2018 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. 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 email: please visit our web site at 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

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Durable and safe access solutions up to 367 ft. or 352-895-1109 4/18/18 3:36 PM

APRIL 2018 • vol 10 no 2


D E PA R T M E N T S 03

Editorial: Wind turbines make good neighbors


Windwatch: Windpower 2018 preview, A sensor for blades, Missed operating opportunities, eBay for the wind industry, and Wind work around North America

40 Fluids and filters: 5 criteria for choosing a gearbox lubricant

44 Condition monitoring: What you should know about vibration sensors

46 Software: Simulating offshore wind projects


Training: Gainful employment in the wind industry


Component close-up: Slip rings

50 O&M: Preparing turbines for lightning strikes


Bolting: Fretting corrosion and how to deal with it

71 Ad Index


Reliability: Transmitting more power over

72 Downwind: A hummingbird inspires a


Transmission: How to meet grid frequency

existing lines

& logistics for better ROIs

wind-power generator

requirements and protect ERCOT’s wind farms



61 U.S. offshore wind industry needs improved foundations

The U.S. offshore wind farm near Block Island, Rhode Island has been built at the cost of $50 million per turbine. That figure must come down for the U.S. offshore industry to grow. That means it is time to put down innovative roots that offer significant cost reductions.

ON THE COVER How Wind Harvest International would upgrade some wind farms.

How to harvest plentiful low-level winds on existing wind farms Vertical axis wind turbines may be the better way to augment wind-farm outputs.

Image by Bonnie Veblen.

65 Innovators and Influencers

Success has many parents says an update of the old saying, and the wind industry is no different. On the pages that follow, we recognize and thank a few of them.



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A Radical Change in Bolting is Coming Your Way Norbar Torque Tools Introduces a New Generation in AC Powered Torque Multipliers

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FINDING SPARE PARTS for aging or discontinued wind turbines is often difficult and time consuming. This is especially true in Europe where wind farms are more fragmented and smaller than in the U.S. What’s more, in Europe there are about 25 different OEMs with many models and types to service. Take Vestas for example. The wind industry is still dealing with its V25s, V27s, V80s, and other units less than 225 kW. No surprise that turbines OEMs want to focus on their newer machines. But how do you find parts for older turbines when the OEM shows little interest? Several firms offer improved and upgraded electrical and mechanical components. The Netherlands-based Spares in Motion took another approach with a cleverly simple idea: It started business connecting buyers with the sellers of spare parts for wind turbines. “That has worked well. More recently we put procurement and distribution services online so buyers can get quotes on parts and labor or look for needed services,” says Managing Director Marc Huyzer. The wind industry is in constant flux so to keep up, the O&M industry must offer new procurement ideas. “Not long ago, for instance, a buyer from a utility mentioned that it was sometimes difficult to find a single supplier for a single purchase, especially for a part that came from a sub-supplier, a company that makes the parts for turbines. Was there an online solution, and if not, could Huyzer’s firm take care of the whole deal with sub-suppliers? He agreed to look into the question and now it does. The web-based store will offer more new things. “Wind industry’s maintenance people will be able to shop for basic materials such as grease, filters, and other things, and pay online,” he says.



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In addition, in early 2017, the company added distribution services. “The trading and procurement service is mostly off-line. So if a request comes in for 200 parts from a maintenance company, we’ll ask for quotes for the parts from several sources and find the best price in the market. It’s a little bit more work on our side but it’s what the market is asking for,” says Huyzer.

Wind industry’s maintenance people will be able to shop for basic materials such as grease, filters, and other things, and pay online. Finding buyers for used turbines and spare parts has been the bread and butter for Spares in Motion. For instance, for only $15,000, this slightly used Vestas V34 could be yours. Spares in Motion has recently branched out into procurement and distribution services.



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The idea for the service comes from the fact that tightening competition occasionally turns companies into poor sports. For instance, an OEM may accept a contract to service turbines from another OEM. If OEM 2 has a protective nature, it may put a price premium or long-lead time on requested parts. Huyzer says being the third party removes that information and poor sportsmanship from the business. Another sought after product are filters. “People often ask for filters and not the cheapest ones. They want several quality and price levels so they can make the best choice for their maintenance situation.” The distribution service and trading will launch at the end of April. W

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Finally, an inexpensive vibration sensor that signals blade problems A CLEVERLY SIMPLE VIBRATION SENSOR made of a loop of thin fiberoptic cable and a fixed wavelength laser promises to take cost out of turbineblade maintenance by letting owners spot problems as they occur. The device, already with two patents, won $150,000 for further development in New York’s PowerBridge competition. “This will let us form the start-up company, LazarOn, to package the sensor, mount it in a turbine, and prove the concept for the early detection of blade damage,” said Dr. Nikhil Gupta, technical lead for the company and Associate Professor of Mechanical and Aerospace Engineering at the NYU Tandon School of Engineering. After gearboxes, turbine blades have always generated the second most costly repairs. Although rare, a blade can break and fall if a growing fracture is undetected long enough. As with other windturbine equipment, detecting cracks and problems early enough makes repairs less expensive. “A preliminary market study found companies are trying to address the blade problem with more complex and expensive sensors, which need someone well versed with the technology. So a shortage of trained manpower would be a problem for them,” he said. Furthermore, because the new design costs less to install than other monitors and requires no manpower to operate, it is far less expensive than ground-based visual and drone inspections, or the only close analog of Fiber Bragg Grating sensors. The latter use expensive tunable lasers and are costly to install and operate, and could be detrimental to blades due to sensor size. “That is not the case with our design,” said Gupta. WINDPOWER ENGINEERING & DEVELOPMENT 

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Reported Insurance Claims

Insurance company Gcube reports that blades account for the second most claims on wind turbines.


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His sensor is made with a small thin optical fiber, about 0.25-mm dia. “This is standard optical fiber used in communications. The system works with fixed wavelength lasers, so the setup is not expensive, which is a big plus. We create a small loop out of this wire, about 6 to 8-mm diameter and mount it inside the hub. It does not have to

The LazarOn sensing element, 0.25-mm diameter fiber optic cable in a 6-mm loop, is easily mounted near a blade in the turbine hub or inside the root so it need not disrupt air flow as would other proposed blade sensors.

be in the blade. Every rotating machine, turbine blades included, has a vibration signature. When damage such as a fracture starts, the signature changes, making the change detectable,” said Gupta. Also, a turbine works day and night making it possible to collects lots of data – which allows self-calibrating of each turbine. It is not necessary to mount the sensor in the blade because its vibration is transmitted to the hub and column. “We have tested it in the lab and it is quite promising. The grant will let us take the next step to a turbine,” he added. Gupta said that part of the PowerBridgeNY competition was to call 100 potential customers.

We have tested it in the lab and it is quite promising. The grant will let us take the next step to a turbine. So his team called companies in the U.S., China, Denmark, and India and found several willing to let him test the sensor. “The grant will pay for the sensor and we will not have to modify the turbine, so the cost of testing the sensor will be minimal to the wind power companies.” As for a timeline, Gupta said the prototype must be finished by October of 2019. “We are hoping for data from at least one wind farm by then.” Ideally, he said, manufacturers would put the sensor in the blade at the factory during production. “But before that they might want full confidence in the technology. A first step is to retrofit existing blades, and then talk to manufacturers about embedding the sensors.” W 12


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Streamline emergency pitch control operations with fast-responding ultracapacitor energy storage

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The turbine monitoring system from Algo Engines is said to assist users in identifying production opportunity and give a more accurate picture of turbine availability and performance. The developer says the platform goal is to place the asset owner and OEM on the same footing. He adds that users can focus on critical aspects of plant performance while the platform performs the data analysis.

Operators still ignoring low hanging fruit in the battle for higher availability IN THE QUEST FOR HIGHER MARGINS, wind-farm owners seem to be ignoring easy opportunities, points out Vibhav Gupta, CEO of Algo Engines. “While predictive maintenance, farm-level optimization, vortex generators, and a range of new options are on the table, there are opportunities in easy reach, which often go unnoticed,” says Gupta. His data analysis platform reveals simpler yet ignored ways to prevent losses in energy and availability. Based on experience across four gigawatts of assets, he listed some of the low hanging fruit in the battle for higher availability and enhanced production. He says they include short duration alarms and restarts, performance issues, and flawed availability calculations. Alarms raised by turbines typically result in stoppage. However, many OEM systems let alarms auto reset, which promptly restarts the turbine. The resets fall under multiple categories – automatic resets, SCADA and operator resets, remote resets, 14


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and local or turbine reset. “Many alarms allow up to three automatic resets. However, during an automatic reset, the turbine will stop and start or pause. This stop-start or TIME CONDITION pause process usually takes between 5 to 15 minutes 13:01:07.384 Alarm depending on the OEM. 13:01:07.543 Start / Ready Who pays for the loss due to this restart?” he asks. 13:11:37.123 Generating / Operating Although he mentions three automatic resets, the process could happen About 10 minutes have several times a day. A turbine in which these elapsed from the time the resets occur is often considered available because turbine was ready to when the reset is instantaneous. “A study of the production began. turbine’s log might reveal that the turbine was down for less than a second, as can be seen from the accompanying table. However, it will take the turbine a while to move back into the generating mode, thereby affecting production,” says Gupta.

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Performance Issues – “We have identified cases in which a turbine did not generate for more than 20 hours in a three-month period due to one auto resettable alarm. Other alarms involved a synchronization delay which put a turbine into a stop-start or pause mode. This sizable production loss usually goes unnoticed,” says Gupta. There may be no quick fix. However, an accurate accounting of energy and time lost due to such alarms will help create a true picture of availability and losses. A quick way to identify underperformance in a turbine, he suggests, compares the nacelle wind speed based power curve to that provided by the manufacturer. The underperforming turbine can then be assessed further. “However, there can be a few complications in this approach. The OEM often comes back with a range of points, such as the nacelle anemometer is impacted by blade movement and hence does not provide a reliable speed, or site conditions, turbulence intensity, and more are not considered in this assessment,” says Gupta. The discussion on the above points is never ending and the nacelle transfer-function method is still not easily accepted. A few simple tests can identify performance issues using this method. Late-starts are one. “We often notice that even though the wind speed is above cut-in, the turbine does not start for 10 to 30 minutes,” he says. Availability calculation − Most wind asset owners have contracts with O&M teams and the OEM for resource and machine availability. “Contracts are never the same, with a range of exclusions and inclusions. Implementing these contracts effectively is critical to validate losses or damage. Many clients say they are unconvinced by the availability numbers provided by OEMs so there is constant need to update and change the figures provided,” he says. Here are a few simple cases that he has worked with:

Errors in the yaw control indicate lost production.

in. “We have noticed cases where wind speeds recorded by turbines is lower when a turbine is down or under alarm. Comparing wind speed with adjoining turbines and a local met mast for the same period can indicate anomalous behavior." • Data loss and communication errors appear when a turbine is down or under alarm yet the OEM system assumes turbine is available. This problem was puzzling at first but multiple examples of such behavior were noted.

In other instances, short duration alarms (<10 min) were ignored in availability computations.

Correcting these instances resulted in higher asset availability. “With our analysis, users can raised the issue with the OEM who made changes in the availability calculations. An asset owner can manually analyze such instances via the SCADA logs, and alarm data for oneoff instances. However, as the number of assets increases, such activity becomes exhaustive. W

Notifications like this one help owners take up matters with the O&M teams or the OEM for further investigation.

• Availability was considered only when wind speed is greater than cutAPRIL 2018

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AWEA WINDPOWER 2018 MAY 7 TO 10, 2018 McCormick Place Chicago, Illinois

Powering wind forward at WINDPOWER 2018 WINDPOWER 2018 gives attendees a chance to enhance their exhibit floor learning experience through targeted education sessions and one-on-one interactions designed to boost wind-related knowledge and business.


EARLY LAST YEAR, American jobs in the wind industry surpassed a milestone: over 100,000, according to a report from the U.S. Department of Energy. Shortly before then, wind-turbine technician became the fastest growing profession in the country. The U.S. Bureau of Labor Statistics expects wind tech jobs to grow by 108% by 2026. That’s more than twice as fast as the second fastest growing U.S. job. What’s more, the wind industry employs veterans at a rate that’s 50% above the national average. And according to Tom Kiernan, CEO of the American Wind Energy Association (AWEA), work in the wind industry is just getting started. “Wind energy is revitalizing America’s economy,” he said. “Building new wind farms keeps American factory and construction


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workers busy, while breathing new life into farming and ranching communities. The wind industry’s powerful growth is poised to continue in 2018, and beyond.” AWEA’s U.S. Wind Industry Fourth Quarter 2017 Market Report outlines much of this progress. For example, the pipeline of wind farms under construction or in advanced development totals 28,668 MW — a 34% increase compared to the end of 2016. There are about 89,077 MW of wind power installed across 41 states. America’s offshore wind industry is also poised to scale up, building on the successful completion of the first U.S. offshore wind project in 2016. By one report, the offshore industry could create another 40,000 wind jobs within a decade.

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New this year are TED-style talks One way AWEA is fostering new from policy leaders, industry experts, wind growth is by supporting the and visionaries on high, level, thoughtdevelopment of students and up-andprovoking ideas for wind. “You'll hear coming leaders that the industry requires. about how technology advances will Expect a strong focus on education at this continue to lower LCOE, and learn year’s WINDPOWER 2018 Conference & lessons from other industries that are Exhibition, the largest wind energy event more mature or have experienced in the Western Hemisphere. similar rapid growth,” said Adams. “The future of wind energy’s The WINDPOWER program will also success is truly in the hands of today feature three General Sessions, one each and tomorrow’s energy leaders,” shared morning of the conference. Sessions and Jana Adams, Senior Vice President for stand-alone presentations will be organized Member Value and Experience at AWEA. into five education stations in the exhibit “WINDPOWER’s Emerging Leaders hall, which are open to attendees and program is designed to help grow and exhibitors. Here’s what to expect at each: groom the next wave of industry talent.” Emerging Leaders provides opportunities Wind energy is revitalizing America’s economy. The for mentorship, powerful growth is poised to continue in 2018, and knowledge sharing, and skill development. The program recognizes emerging talent and connects current industry leaders with future wind-power professionals. The U.S. Department of Energy Collegiate Wind Competition is also returning to this year’s event. The competition allows students from across the country test their skills and engineering know-how by developing business plans, designing model wind turbines, and showcasing hypothetical utility-scale wind farms. A team of wind industry leaders will serve as judges for the event. “As per the WINDPOWER 2018 tagline, Powering Forward to Reach New Heights, we are hoping to inspire, educate, and grow the wind industry in productive ways,” said Adams. Powering thought leadership AWEA also aims to bring thought leaders together to swap ideas and share meaningful discussions that drive the industry forward in the most efficient ways possible. According to the WINDPOWER 2018 website: “The program will feature speakers with ‘disruptive’ and innovative ideas that will continue to strengthen wind energy’s value proposition and challenge the current way we do business.” APRIL 2018

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wind industry’s beyond.

Tom Kiernan, CEO of AWEA, speaking up for wind power during a presentation at last year’s event.



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W I N D W A T C H WINDPOWER 2018: A few conference highlights Power Station (powered by Siemens Gamesa Renewable Energy). Gain a better understanding of how wind experts are pushing for global growth through market expansions and new commercial opportunities. • Tech Station (powered by GE Energy) Hear from the top minds in business, academia, and government on innovations in wind that could fundamentally change the industry. • Operations Station (powered by UL). Learn how to analyze management strategies to better address operational lifecycle issues that challenge windfarm owners and operators. • Project Development Station (powered by UL). Exchange ideas and discuss key topics for developing a successful wind-power project, including siting, permitting, forecasting, monitoring, connecting to the grid, and more. • Thought Leader Theater (powered by Mortenson Construction). This station brings together industry experts to discuss lessons learned and company successes so others can achieve the same. •

“Across the country, wind is welcome because it means jobs, investment, and a better tomorrow,” said Kiernan. “Let’s power forward, propel new growth, and take our industry to the next level!” W

DATE Monday, May 7 (Pre-conference)



Wind 101 – Introduction to Wind Energy


Opening Reception

5 to 7pm

Tuesday, May 8

Welcome & Opening General Session

10 to 11am

Analyst Hour: U.S. Wind Market Forecast

11:30 to 12:30pm

Cybersecurity for Wind Farms

1 to 1:45pm

Project Siting, Finance & Community

2:15 to 3pm

Large Wind Turbine Manufacture Forum

3 to 3:45pm

Frequency Control for Grid Support Extended Booth


Wednesday, May 9

General Session Powering Forward

3:30 to 3:55pm

6 to 8pm 10 to 11am

Offshore Wind: Preparing U.S. Ports

Women of Renewable Industries & Sustainable Energy Awards Luncheon

12 to 1:30pm

How to Calculate Wind Farm Remaining Useful Lifetime

2:30 to 2:55pm

New Research on our Communities and Jobs

2:45 to 3:45pm

Energy Storage and Utility-scale Wind

3:30 to 4:30pm

Poster Reception

4:30 to 6pm


11 to 12noon

Thursday, May 10

11:30 to 12:30pm

View the full agenda here: < Sessions.aspx?View=Sessions&ID=504&sortMenu=106001>



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Wind work around North America The offshore wind industry may have had a slow start in the United States but plans are well underway with reports of more than two-dozen offshore projects proposed for development. New development means new jobs, and the industry is preparing for a welltrained workforce. For example, Vineyard Wind’s new $2 million “Wind Workforce” initiative will recruit, mentor, and train local, Massachusetts’ residents for high-skilled careers in the offshore industry. Federal lawmakers have also introduced the Offshore Wind Jobs & Opportunity Act, legislation that will assist governments, schools, unions, and nonprofits develop curricula, internships, and safety programs, for a strong offshore wind workforce. The wheels are in motion. Now it’s time to start building offshore wind farms.



Ørsted is coming to Atlantic City


Vineyard Wind to assess offshore wind impacts

7 4 6 2 1 5 8 3

Offshore wind developer Ørsted, formerly Dong Energy, says it will open an office in Atlantic City in May. The company has a lease area off the Atlantic coast that has the potential to accommodate more than 1 GW of offshore wind. Ørsted has proposed development of Ocean Wind, an offshore wind farm about 10 miles off the New Jersey coast.

Vineyard Wind and the University of Massachusetts Dartmouth’s School for Marine Science are conducting pre and post offshore construction assessments of fisheries and associated ecological conditions. The assessment will be used to inform future permitting and public policy decisions regarding wind facility siting and construction impacts.


EDF RE to acquire Fishermen’s Atlantic City project


Bay State gains ‘FAST-41’ status


EDF Renewable Energy (EDF RE) has entered into a preliminary agreement with Fishermen’s Energy to acquire their fully developed 24-MW Atlantic City project, which has suffered financial setbacks. The offshore wind farm will create statewide jobs in New Jersey, and, according to EDF RE, serve as a laboratory for testing of new avian monitoring and marine mammal sensing technologies.


Ørsted and Eversource’s Bay State Wind — a proposed 400 to 800-MW offshore wind project to be set off of Massachusetts’ South Coast — has been granted status under Title 41 of the Fixing America’s Surface Transportation Act. “FAST-41” improves the timeliness, predictability, and transparency of the Federal environmental review and authorization process of approved infrastructure.

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California’s push for floating offshore wind


More wind jobs coming to Massachusetts


Offshore developer, Deepwater Wind says it will assemble the turbine foundations for its proposed Revolution Wind and battery storage project in Massachusetts, and is considering New Bedford, Fall River, and Somerset as possible fabrication locations. The developer is also seeking proposals from boat builders for the construction of purpose-built crew vessels for the project.

California’s Redwood Coast Energy Authority has assembled a consortium of companies that will enter a public-private partnership to develop a 100 to 150-MW floating offshore wind farm, more than 20 miles off the coast of Eureka. The project is expected to drive support for floating wind farms, and investment in infrastructure at the Port of Humboldt Bay and other nearby onshore facilities.

Bay State Wind is collaborating with a steel fabrication and a construction company to open and staff a Massachusetts facility to manufacture offshore wind foundations and components. The facility is expected to generate about 500 annual construction jobs and 1,200 indirect jobs. The jobs will include welders, blaster painters, steel fabricators, and other associated trades.

Massachusetts turbine and vessel builders wanted

New Jersey signs offshore wind development order

New Jersey Governor Phil Murphy has signed an Executive Order directing the New Jersey Board of Public Utilities (BPU) to fully implement the Offshore Wind Economic Development Act, or OWEDA. The Order directs the BPU to establish an Offshore Wind Strategic Plan for New Jersey, moving the state toward its goal of 3,500 MW of offshore wind generation by the year 2030.



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Michelle Froese Senior Editor Windpower Engineering & Development

Hand injuries from misuse of tools and equipment are the number-one cause of injury for wind techs. Proper equipment use and training is essential to a safe day on the job for a tech. Photo courtesy of Ecotech

Gainful employment in the wind industry


f you keep up with news in the wind industry (and even if you don’t), there’s a good chance you’ve heard that many of its sectors are looking for talent and hiring. In fact, in 2016 the U.S Department of Labor announced growth in the field is expected to increase by 108% over the next 10 years. That rate is more than twice that of the second fastest growing job sector (occupational therapy assistants). Indeed, according to the Bureau of Labor, wind-turbine technician is the fastest growing job in America. “Right now, there are more than nine million people around the world that work in renewableenergy industries, and it has been estimated that nearly 50,000 additional trained staff will be needed by 2030 – and that’s in the wind-energy industry alone,” shares Henry Bailey, the Global VP & Head of Utilities Industry Business Unit at SAP, the world’s third largest independent software manufacturer. That’s good news for clean-energy advocates and job seekers. However, it does come with a set of challenges, as Bailey points out. “The downside is that we’re facing a significant problem when it comes to addressing the talent shortage for technical specialists, such a wind techs, which are highly sought after in the industry.”



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At the same time, technology is moving at a rapid pace (for example, the announcement of a 10plus megawatt turbine could come at any minute), and the skills needed to safely and efficiently keep up as a wind tech are growing and evolving. “Recently, SAP surveyed 3,100 people and found that 48% of industry leaders believe investing in digital skills and technology are the most important factors for driving revenue in the next two years,” says Bailey. “In the wind industry, professionals are looking at smart technology and digitalization to further the use and development of turbines, which requires a greater level of skill.” He adds that one way for talent to learn the specialized skills that aid in turbine development and O&M is by creating more mentorship and apprenticeship programs. “This opens more lines of communication, and provides greater opportunities for sharing ideas and tactics between new talent and experienced workers.” Auston Van Slyke, a Program Director at Colorado’s Ecotech Institute, agrees. Once a traveling wind technician, he currently teaches a 60-hour wind-turbine safety course at Ecotech, the first and only college in the U.S. focused entirely on careers in the fields of renewable energy. “I used

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to hire new technicians, and it became quickly apparent how hard it was to find someone with the right combination of skills and values to succeed as a wind tech,” he says. “Today’s wind turbines are more advanced, Internet connected, and smarter than ever. So, it follows that today’s wind techs need to know more about computers, Internet protocols, fiber optics, and frequency converters. Good training is essential.” So what training is needed to become a wind tech? That partially depends on experience. The exact training required of a wind technician will vary based on the job and a tech’s skill level, says Van Slyke. “If you have a lot of related experience or built up technical expertise, then a new wind tech may be OK with the basic 40-hour course — most companies put new hires through a standard 40-hour course, which includes climb, rescue, electrical safety, and company procedures,” he explains. “However, if you’re brand-new or lack the necessary skills and knowledge, a three-month tech course is currently the shortest available program in the U.S., followed by a nine-month program or a two-year associate degree.” He says the associate degree is one way a technician can work up to a management role. “Additionally, it is essential to get an OSHA 10 or 30-hour certificate, as well as a Climb and Rescue certificate, in addition to the First Aid/CPR certificate.” OSHA, the Occupational Safety and Health Administration, is the main federal agency responsible for the enforcement of safety and health legislation in the U.S. “Another important feature to look for in a program is equipment and tool training,” says Van Slyke. For example, using tools and personal protection equipment correctly is essential to a safe and long career as a wind tech. “Even seemingly minor things such as training on multiple types of Fluke meters, like the megohmmeter and 87 model, is important.” Fluke has become the standard make for electrical test meters. Of course, wind techs are typically expected to climb 60 to 80 meters or higher as part of a regular workday, so safety must APRIL 2018

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come first. “Don’t take shortcuts — with training, tasks, or safety,” he advises. “And don’t get lazy with personal protection equipment. Wind technicians get a lot of hand injuries that could be prevented with gloves and the right tool for the job.” Some of this is common sense, but a lot comes back to training and education. Although many new turbines are equipped with elevators or climb assists to ensure a safer ascent and descent, and many tools come with smart meters (such as digital torque guns that ensure a bolt is automatically tightened to exacting standards), wind technicians are also expected to keep up and work with such digital advances. “It’s a fast-paced world,” says Bailey. “Advanced software and the industrial Internet of things, which connects devices, has made many tasks faster and

easier, which is great. But these digital tools also require knowledge to be used safely and effectively.” Van Slyke says life as a wind tech can be rewarding, and particularly with the right training. “Typically wind turbines don’t get looked at for months at a time. A wind tech’s attention to detail can save a machine from failing in the middle of the night, and that can impact a wind farm and the industry over time.” It could also save a wind owner thousands of dollars in downtime and lost production. “Wind is a relatively new industry and not everything has been thought of yet. Wind technicians have the opportunity to make changes to manufacturing or to user manuals, or suggest new tools and devices. My advice: Take your time to learn the proper skills, stay updated on new tools and techniques, and always do the best quality work.” W

WIND TECH TRAINING STANDARDS Here are a few of the basics for working at height and on wind turbines. • • • •

For working at heights, climbing, and rescuing, the standards are OSHA 1910 & 1926, ANSI Z359 & Z490 and NATE CTS Industry Standards. Electrical safety standards are NFPA 70E and NESC Keep First Aid, CPR, and AED the American Redcross updated As it pertains to technical skills, there are dozens of organizations that have created standards. The Global Wind Organization, a recognized leader, pertains only to Europe. Currently, the American Wind Energy Association is working with American National Standards Institute to create similar technical skill standards in the U.S.



4/18/18 3:49 PM


Jesse Shearer Slip Ring Engineering Supervisor United Equipment Accessories

How to extend slip-ring life in wind turbines


A United Equipment Accessories’ technician assembles brush harnesses on a slip ring.



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healthy wind turbine is a productive turbine, one that can improve a wind owner’s ROI. However, even the smallest components can impact a turbine’s overall efficiency if damaged or overworked. Proper maintenance and design of turbine components are vital to keeping a wind farm running reliably, and avoiding unscheduled repairs or costly replacements. One small, but important component of every wind turbine is the slip ring, which is used for power and pitch control systems. Slip rings transfer power to motors in a turbine’s blades and share data back to the hub from sensors in the blades to optimize wind generation. As wind turbines become more powerful, slip rings are upgraded and refined to work optimally in the harsh environment of a nacelle. A well-designed slip ring requires little maintenance and has a long lifespan. Given that a slip ring in a wind turbine may see 10 million revolutions or more per year, annual inspections and care are still necessary. Here are a few ideas for extending slip-ring life in wind turbines. Inspect visually Predictive analytic platforms, which monitor and extract data for trending analysis, have garnered much attention in the wind industry. Such systems can provide valuable information about turbine performance, component fatigue, or expected production.

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However, annual visual inspections should also be scheduled as part of a good maintenance plan. Sometimes a good set of eyes are all thatâ&#x20AC;&#x2122;s needed to identify maintenance issues, such as worn out brushes that could cause electrical failure or damage. This step serves as an extra preventative measure to catch potential problems early on that may save time, costs, and downtime.

It is typically fastest and easiest to eliminate dust using compressed air or a small vacuum system. Make sure the method used keeps dust particles away from power or signal transmission. Slip rings that are overly contaminated from dust or dirt can cause a loss of transmission or communication, so it is important to ensure component cleanliness.

Remove dust Wind turbines must withstand harsh conditions including variations in blade rotation, temperature fluctuations, and contaminates such as dust. Dust removal is essential to keep slip rings in top form. This can be done during the annual visual inspection to save costs and time scheduling another trip uptower.

Keep â&#x20AC;&#x2DC;em clean Unfortunately, dust is merely one contaminant to keep in check when maintaining slip rings. Leaking oil and water can quickly compromise the efficiency of a slip ring and result in malfunction. Also, other contaminants such as sand, dirt, or even humidity can affect slip rings, depending on a turbineâ&#x20AC;&#x2122;s location.

An easy way to break a slip ring and ensure a costly replacement is by using it as a climbing aid or step during maintenance and inspection. This may seem self-evident, but the misuse of slip rings does happen fairly regularly at wind sites. United Equipment Accessories includes a warning sticker noting that the component is not to be used as a climbing device, which it says has led to a decrease in the need to repair or replace its slip rings.

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Assembled slip rings are ready for testing prior to installation in wind turbines.

It is critical to inspect slip rings, and clean its enclosure at least once a year. Typically, brush dust removal is recommended for optimal performance and to minimize buildup of future contaminants. Check with the slip ring or turbine manufacturer for recommended maintenance tips. Replace brushes Brushes in turbines are are used as electrical contacts for power transmission. On slip rings, an electrical current or signal conducts through the brushes to make the connection. Worn brushes can cause damage, which can result in costly machine downtime. Advanced designs can last up to 200 million revolutions, or an average of 10 years, depending on the number of hours the turbine is in operation and the speed of the turbine. However, it



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is important to monitor brushes and replace them prior to failure to prevent damage to the slip ring and a turbine shutting down. Many slip ring designs require full brush replacement, even if only one brush is worn down. Consider quality when selecting brushes. For example, one brush design allows access to a slip ringâ&#x20AC;&#x2122;s enclosure and replacement of a single brush at a time, eliminating the need to change the whole section. These brush designs also work without lubrication, unlike some conventional designs. Proper maintenance of windturbine slip rings will typically result in less downtime and fewer unscheduled maintenance trips, ultimately saving time and costs. Performing scheduled, routine component maintenance is a cost-effective long-term plan for a productive wind farm. W

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AWEA 7 - 10 MAY 2018 CHICAGO, IL, USA BOOTH 3212

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B O LT I NG Scott Eatherton CEO Wind Driven LLC

How to recognize fretting corrosion and what to do about it


uestion: What is the quickest way to find the weak points in a mechanical design? Answer: Install it in a wind turbine. Itâ&#x20AC;&#x2122;s not a joke. Load spectrums in wind turbines are unique. The wide variations in wind speeds produce wide ranges of shaft torque, nacelle motion, and faulting events that lead to high-frequency vibrations, impact loading, and torque reversals. So in addition to the fatigue modes of micropitting, axial cracking and spalling, the near constant changes in acceleration subject wind turbines to a well understood, highly destructive, yet littlerecognized wear mode: Fretting corrosion.

Fretting corrosion affects many critical wind turbine systems. It may be, in fact, their most common nonfatigue failure mode. Unlike the chemical corrosion of exposed external surfaces, fretting occurs in the contact zone of two or more parts under pressure. This includes bolted connections, gear teeth, roller bearings, and interference fitted parts. The four-panel photo illustrates the destructive power of fretting in a wind turbine (WT) gearbox. During disassembly of the failed gearbox, we unexpectedly found an additional failure. Several large cracks were found in the key slot of a shaft, initiated by fretting corrosion. This was an eye-opening experience. Ever since, Iâ&#x20AC;&#x2122;ve been on the lookout for fretting corrosion, especially during warranty-sweep inspections.

Locations of fretting corrosion in wind turbines

Look for fretting corrosion in these places in a wind turbine.



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Fretting corrosion occurs when: • Two metal surfaces are in direct contact. • Vibration causes minute repetitive oscillatory motion between the surfaces. • Contact pressure sufficient to cause shearing-off of minute high spots during vibration. • Oxygen is present, from the air or dissolved in lubricants.

RIGHT: Cracks in a gearbox shaft were initiated by fretting corrosion. At the top right, the arrows point to cracks. Close-up images at bottom show fretted surfaces.

• Metallic bonding: Molecules and crystals form when metallic atoms all benefit by constantly shuttling electrons throughout the piece of metal.

Crystal images courtesy of

How shape influences abrasiveness

Fretting also occurs in both lubricated and lubricant-free connections. • When a lubricant is present, fretting takes the relatively benign form of false brinelling. The tiny pieces of iron sheared from rough surfaces are oxidized. The particular species of iron oxide produced is magnetite, a black and highly magnetic material. WINDPOWER ENGINEERING & DEVELOPMENT

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But what makes these two oxides of iron so abrasive, and why is hematite so damaging and magnetite relatively benign? The answer lies in the form of atomic bonding and the shape of the crystals. Here we are concerned with two of the three forms of atomic bonding: • Ionic bonding: Molecules and crystals form when atoms seeking to gain electrons meet atoms seeking to give up electrons. Most abrasives are ionically bonded compounds.

BELOW: Hematite crystals (left) are shaped like cutting-tool inserts (center). Magnetite crystals (right) are not an optimal shape for an abrasive.


• When lubricant is absent, fretting corrosion produces hematite, a highly abrasive species of iron oxide. Hematite is a fine-grained, reddish to red-brown powder. It is used commercially to polish gems and is commonly known as jeweler’s rouge.

Ionic bonds are strong and highly directional, resulting in materials that are hard, extremely rigid, and strong. They are also inelastic, brittle and lack a toughness needed to resist cracking. These characteristics make ionic bonded materials self-sharpening, so when they break, rather than bend or deform, they form more sharp edges and corners. Contrast this with metallic bonds, which are strong but not highly directional. These result in materials that are hard, have elasticity, ductility, and toughness but are vulnerable to abrasion. Both hematite and magnetite have a Mohs scale of hardness equal to a knife blade, about 6. The reason hematite is so abrasive lies in the shape of its crystal, as shown in the illustration How shape influences abrasiveness. X-ray diffraction is the definitive method of identifying hematite and magnetite, for example, during a warranty sweep. The cost is currently about $750 per sample due to equipment. Recently, however, using technology licensed

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from NASA, Olympus has designed two relatively affordable products in bench-top and portable versions. These instruments are user-friendly and take only a few hours to master. The photo above shows the portable version in field use and the results of a WT sample analysis. The graph’s x-axis is the diffraction angles of X-rays from the planes in a crystal’s lattice that uniquely identifies a material. The y-axis is intensity. The vertical green lines indicate hematite, red is magnetite and blue line is iron. The failed bolts on angle brackets provide more examples of fretting in WT components. In each case, fretting wears away material in the bolted connection. As material wears away, looseness increases and with it the rate at which fretting wears away material. Fretting is therefore often self-aggravating.

The portable X-ray diffraction equipment from Olympus has brought down the cost of tests for fretting corrosion. The equipment (left) shows the few tools and supplies required. The instrument provides a lot of information (right) but most important is that the sample is 55% hematite, 30% magnetite, and 15% iron.

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Fretting has been spotted between a main bearing housing and a main frame.

Additional gearbox housing wear appears near bolt holes. Photos courtesy of Renew Energy Maintenance

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B O LT I N G The yaw deck bolts have failed due to a design defect.

Bolts store elastic potential energy when torqued or tensioned. Longer and higher strength bolts store more energy and resist loosening from fretting. This energy is stored by elastically stretching the bolt by about 0.1% or 0.001-in. per inch of bolt length. Whether torqued or tensioned, the stored elastic energy is known as preload. This preload lets bolts withstand the highly variable load spectrum found in WTs. So consider: If fretting wears away just 0.005-in., a 10-in. bolt loses half its preload and will eventually fatigue and fail. Here are a few methods for mitigating fretting corrosion in bolted connections: • In newly installed WTs, re-tighten all critical drivetrain fasteners after a few hundred hours to compensate for relaxation in fasteners, the bolted components, and paint and coatings. • Increase fastener torque. Use torque-tension calibration to avoid over-tightening and ensure that the torque used creates required preload. • Use direct tensioning in preference to torquing. • When torquing bolts, reduce the variability in their preload by using an anti-seize compound on threads. The torque required will be much lower than dry bolts. So to avoid yielding bolts use a torque-to-tension calibration tool. • Use spacers to increase bolt length. Longer bolts reduce preload loss as fretting wears away material in a bolted connection, prolonging the life of bolted connections subject to fretting corrosion. • Use friction shims to reduce the relative motion between mating surfaces, and thereby the initiation or rate of fretting wear. These are thin alloy steel shims embedded with friction enhancing particles such as corundum, tungsten carbide, or diamond. • Use sealants to exclude oxygen. W WINDPOWER ENGINEERING & DEVELOPMENT 

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RE L I ABI L ITY Jake Gentle Senior Power Engineer Idaho National Laboratory

How to transmit more electrical power over existing lines

Heat Transfer Model

Helping utilities make the most of their existing transmission and distribution infrastructure

Power lines are heated by the sun and when transmitting power. They are also cooled by the wind and weather.


elieve it or not, sunny skies and calm summer days can negatively impact the ability of the electric grid to transfer power. The naturally occurring heat surrounding transmission lines limits its capacity. A windy or cold day, however, has a cooling effect that allows transmitting more power. That means monitoring the weather lets a utility safely unlock additional grid capacity, which enables more reliability and resilience for the energy infrastructure. Utilities across the nation are weighing the tradeoffs in providing additional power for homes, industry, and critical services through traditional transmission expansion planning. Overhead transmission lines (TLs) are thermally limited to the amount of electrical current they can carry due to the physical properties of the conductor. Conventionally, the current-carrying capacity of TLs is set to static or seasonally varying values based on a conservative assumption of the environmental conditions (e.g., low wind speed and high ambient air temperature) over the year or season. However, this approach typically underuses existing transmission assets because these conditions are



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present only for short periods. In fact, conductor cooling by local weather often provides additional ampacity headroom. Ampacity is a capacity for amperage. Dynamic line rating (DLR) is a technology that dynamically computes ratings of the TLs based on the heat-energy balance between the total amount of energy absorbed and dissipated in the conductor, as shown in the heat transfer model. (The full heat balance equation appears at the bottom of the image.) Real-time monitoring of electrical and environmental parameters can maximize the line capacity use of critical overhead TLs. DLR significantly increases the wind energy hosting capacity of existing TLs because of the natural synergy between wind generation and increased conductor capacity at times of high local wind,. As utilities consider the cost for updating aging infrastructure to better connect resources to loads, unlocking extra capacity within existing transmission lines becomes attractive. So-called â&#x20AC;&#x153;non-wireâ&#x20AC;? alternatives offer similar advantages in efficiency and reliability of system operations without large investments.

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Cabling your entire wind turbine â&#x20AC;&#x201D; rotor tip to tower base.

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THE VALUE OF COMPUTATIONAL FLUID DYNAMICS Almost every country has created wind resource maps to find potential windy places suitable for building new wind plants. Modelers use a wide range of methods to create these wind resource maps. Yet new methods are needed to capture the detail required to enable dynamic line rating, which could boost transmission and distribution line capacity by 10 to 40%. WindSim has developed a wind atlas method using specialized software. The approach enables dynamic line rating modeling and simulation that can expand over hundreds of miles. To be as accurate as possible, the method combines wind speed and wind direction data from smaller simulation areas and is based on scaling against measurements where available. To create these wind resource maps, scientists have many modeling options to choose from, including mesoscale modelling, linear methods and computational fluid dynamics (CFD).

Using mesoscale models has the advantage that the entire area of interest can be fully covered by one model, while other approaches require combining several simulation areas afterwards. However, mesoscale modeling does not reach the horizontal resolution necessary for a reliable wind resource map. For example, mesoscale models reach their limits in rough terrain because the roughly 1-km resolution is too coarse and forces over-simplified mountainous terrain. By comparison, CFD can simulate the wind flow with a horizontal resolution of 10 m, or even 1 m with specialized data collection. As a result, the CFD approach can better predict the flow pattern within smaller valleys and in very difficult terrain. For that reason, it has become common to use CFD to generate wind resource maps of smaller areas, and then combine the different simulation areas in the end to see the big picture.

The WindSim Power Line Optimization Solution identifies opportunities for additional power capacity, helping utilities fully use existing transmission and distribution lines throughout their power grid. The software improves system reliability and increases its resilience by monitoring power

Power lines can sag in low wind.



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capacity in real time. This lets the utility better manage existing infrastructure, and provides planners more leeway and flexibility as they prioritize the timing of conductor replacements, line rebuilds, and new construction to meet transmission and distribution expansion plans. It also allows costs to be spread over longer periods. Providing advanced data directly to operations and control centers lets utilities make better decisions based on more accurate and reliable data with less uncertainty and better situational awareness. For example, if a transmission line connects a wind farm to the grid, the same wind that generates power also cools the transmission line. Such a condition allows installing more wind turbines without the cost of transmission enhancements. In addition, the cost of electricity can be set at a premium because of the limits or congestion in the connection of generation and loads. When tracking weather conditions or, more importantly, weather forecasts, the utility may raise limits to provide additional capacity and alleviate transmission congestion, freeing up access to lower cost generation. Dynamic line rating integrates realtime weather station data with terraindependent, computational fluid dynamics, wind-flow modeling, and weather

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forecasting for determining a real-time line rating and accurately forecasting line ratings. Real-time ratings are available in increments of minutes to hours, and forecast ratings are available in increments of minutes, hours, and even days. The dynamic line rating may extend cost savings for energy consumers because of the additional power transmission. Static line ratings are based on a fixed set of conservative environmental conditions to establish a limit on the amount of current a line can safely carry without overheating. The innovation uses commercially available weather stations and requires no hardware devices on the actual lines. The data from these stations, in combination with a weather analysis enhanced by computational fluid dynamics, lets utilities safely and confidently use dynamic line ratings instead of the often overly conservative static-line ratings that have been the norm. The Idaho National LaboratoryWindSim approach allows for the complete coverage of all structureto-structure spans of the transmission line instead of single-locational measurements. For more than five years, Idaho National Laboratory has led the development of this weather-based

Sorted calculated ampacity improvement and load headroom Plot of improvement in amps of the weather based ampacity calculation versus a normalized static line rating (SLR). The terms with (t) are functions of time.

dynamic line rating methodology. It uses computational fluid dynamics and forecasting innovation funded by the U.S. Department of Energyâ&#x20AC;&#x2122;s Wind Energy Technologies Office, in partnership with WindSim through joint collaboration on the research

The illustration of terrain (in orange) shows the large scale often under consideration. The gray boxes along the power lines are more discrete CFD models that consider the local terrain.

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and development of this tool. The relationship has now advanced the technology for the electricity sector by improving the capability of modeling and transferring weather conditions to every span on the line to accurately perform dynamic line ratings, across a large geographic area with high reliability and certainty. Weather-based dynamic line rating has been validated through three industry pilots to ensure it provides a smart-grid energy solution for removing artificial or systematic power flow constraints. This is done by informing system planners and grid operators of available transmission and distribution capacity that was previously restricted by static line ratings. The WindSim Power Line Optimization Solution is currently deployed and validated in partnership with other electric utility partners and commercial meteorological solution providers, which includes the U.S. National Oceanic and Atmospheric Administration. WindSim is looking for additional partners to further deploy this solution. W



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T R ANSMI SS ION N i c h o l a s Wa t e r s Key Account Manager Bachmann electronic Corp

Bachmann’s U.S. team recently received a request to develop a solution consisting of hardware and software capable of acquiring and archiving high-resolution frequency data for a 170-MW wind farm operating in Texas. The customer’s existing hardware lacked the capa-bility to collect highresolution frequency data and calculate frequency performance calcula-tions at the resolution necessary to prove operational compliance for the ERCOT region. The goal of the project was to help the customer achieve a state of compliance within the ERCOT region according to standard BAL-001-TRE-1 through implementation of a fully automated solution.

Meeting grid frequency requirements and protecting wind farms within ERCOT Meeting operational compliance within the ERCOT region for wind sites is important from a safety perspective and, failure to do so can result in hefty fines for project owners. This was motivation for one 170-MW Texas wind facility — which lacked the necessary hardware to collect high-resolution frequency data required for demonstrating compliance — to seek a third-party solution. New hardware and software developments make it possible to provide the necessary data outlined in standard BAL-001-TRE-1, and automatically acquire and archive complete history for the site, enabling site operators to reconstruct grid events down to the second with mHz frequency resolution.


n April 2015, NERC released a standard entitled, Primary Frequency Response in the ERCOT Region (BAL-001-TRE-1). Its purpose is to “maintain interconnection steady-state frequency within defined limits.” By establishing tight limits for frequency tolerances and corrective actions, grid stability is ensured throughout the region. Balancing Authorities, operators, and owners are also provided with performance metrics for their role in the integrity of the grid.



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Wind farms operating in the ERCOT region work with defined frequency limits for which they are allowed to supply power to the grid. These limits are defined by the Max Deadband, a term that describes safe operating bounds around the ideal frequency of 60.000 Hz, at which the grid should be operating. Within BAL-001-TRE-1, the Max Deadband is stated as ±0.017 Hz for wind turbines, meaning that if the frequency on the grid is measured outside the operating limits defined

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by the Max Deadband, the Balancing Authority issues curtailment commands to the plant operators. Each exceeded measurement of the Max Deadband is called a Frequency Measureable Event (FME) and the time at which the event occurs is denoted by t(0). The amount of curtailment required for a given site is dependent on the size of the site and the frequency deviation from the Max Deadband. Here’s the formula for calculating how much curtailment is needed when the frequency deviation has exceeded the Max Deadband:

AN INTRO TO ERCOT According to its website, the Electricity Reliability Council of Texas (ERCOT) manages the flow of electric power along the Texas Interconnection and oversees the majority of the state’s electric load. With over 40,000 circuit miles of high-voltage transmission under its governance, ERCOT’s primary focus is to ensure the following:

Having over 90% of the state’s electric load under its governance, the ERCOT region covers nearly the entire state of Texas with a relatively small number of counties along the state’s perimeter falling into the Western Electricity Coordinating Council, Southwest Power Pool, and the Southeastern Electric Reliability Council.

• System reliability, including planning and operations • Open access to transmission • Retail switching process for customer choice • Wholesale market settlement for electricity production and delivery.

Total curtailment needed = [(Total MW capacity for site)/2.983 Hz] x Hz over max deadband Ctotal needed = [Tsite cap / 2.983 Hz] x Dmax where Ctotal needed = Total curtailment needed, MW; Tsite cap = Total site capacity, MW; and Dmax = Max deadband, Hz.

Each time an FME occurs, the standard states that the Balancing Authority is required to notify the Compliance Enforcement Authority (in this case, ERCOT) within 14 calendar days and provide detailed frequency data pre and post-event. A wind operator is responsible for making the appropriate corrective action to bring his or her site back into the defined operating range. In addition, the wind operator is required to collect and provide specific frequency data for the wind farm — demonstrating corrective actions, response, and frequency correction in a timely manner. Although a more detailed description of the formulas can be found within the standard, the calculations rely on one-second frequency data with mHZ frequency resolution. A window of this one-second frequency data must be provided, which captures 16 seconds prior to the FME and 60 seconds, following the FME. It is important to note that the responsibility of providing this data falls on the wind-farm owner and operator. The standard provides Balancing APRIL 2018

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Authorities, wind owners and operators with a 30-month implementation plan divided into four compliance milestones. Failure to achieve full compliance within 30 months can result in fines. At the time of this request, the windfarm owner in this case had already faced fines. Due to the hardware limitations of the site, the existing governor was incapable of acquiring the data necessary for performing the frequency response calculations outlined within the standard. Using Bachmann’s Grid Measurement and Protection module, the GMP232/x, a M1 solution was developed that recorded a one-second sliding window average of the grid frequency and archived each second’s frequency average with respective date and timestamps. Due to the frequency resolution achievable through the GMP232 module, the one-second frequency data was collected with 0.1 mHz resolution, but rounded to the nearest mHz for this application. Frequency, power, and power factor were also acquired and archived with corresponding date and timestamps for post processing.



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The power values were recorded with kW resolution. Curtailment required based on actual frequency was also calculated and stored. Daily files containing 86,400 data entries per day (one-second frequency average/sec generated for each second of the day) were automatically saved in CSV format, organized into monthly folders, and compressed into a single annual folder at the end of each year. The M1 controller interfacing with the GMP module was programmed to upload data to a server and clear old data stored locally on the device. In the event that communication to the unit is disrupted, the controller is capable of storing nearly three years of data on its 4-GB CF Card. Once communication is reestablished, the M1 system then uploads the backlogged data to the server. An initial proposal suggested solely providing the frequency data around each FME needed for computing the values specified in the standard. The downside of such a narrowly focused solution

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was twofold. One, it failed to provide any context surrounding each FME. Without additional information leading up to or following the event, it was impossible to recalculate the frequency response measurements or recreate previous events. Second, this suggestion was far from future proof in the event that new modifications to the standard would be implemented in coming years. High resolution, onesecond frequency data for each day, month, and year let the customer recalculate previous calculations and perform additional calculations that may be required by future modifications to the standard. This allowed the customer to see if their previous operational strategy would continue to be in compliance going forward or if additional modifications would be needed. Since deployment, the GMP232 module has successfully provided the data needed to calculate necessary frequency performance values and bring the site into compliance with BAL-001-TRE-1. It has also let the owner retroactively analyze their siteâ&#x20AC;&#x2122;s frequency,

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Bachmann’s hardware setup containing an MX213 controller and a Grid Measurement and Protection Module (GMP232).

power, and power factor data for previous years, with minimal data storage demand on their server. Although this project was developed to satisfy requirements for a wind site operating within the ERCOT region, it is compatible with any operating wind farm that contains voltage and current transformers at the wind farm feed-in point (connection point to the grid) in any electric reliability council. Most wind farms typically include hardware for measuring the wind farm’s power and frequency at the grid connection point. However, the frequency resolution

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achievable through the GMP232 module, coupled with automated historization of FMEs and power data, allow customers to reconstruct grid events, making this solution unique. Bachmann’s M1 setup, which uses the GMP232 module, provides increased resolution and accuracy, and the ability to build a complete history for the site’s performance down to the second of operation. This GMP/M1 setup only requires access to the voltage and current transformer located at the connection point to the grid to make its measurements. W



4/18/18 5:28 PM


Brian Burks, CLS, OMA 1 Senior Application Sales Engineer AMSOIL

5 criteria for choosing a quality gearbox lubricant


he wind industry is changing and growing quickly. There are now more than 89,077 MW of wind energy installed across 41 states. To keep up with clean-energy demands, wind turbines have had to become more powerful and reliable. This means wind turbines are expected to run more efficiently and for longer periods with less maintenance — and that means every component must operate flawlessly. Turbine lubricants play a critical role in reliable equipment operations and maintenance. It can help protect system components, minimize unscheduled downtime, extend maintenance intervals, reduce costs, and enhance safety (thanks to fewer trips uptower). There are a number of lubrication points in a wind turbine, including generator bearings, pitch and yaw systems, and — perhaps most essential — the gearbox. A well-lubricated gearbox is critical to reliable turbine operation and production. Just a few years ago, oil changes were done every three to five years in gearboxes because of lackluster performance that degraded quickly over time. Lubricant

AMSOIL’s oil-change truck is positioned for service at the base of a wind turbine.


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performance was typically fraught with contaminants such as water, foam, or the accumulation of excess sludge that required frequent maintenance checks. However, it is extremely costly and labor intensive to change the oil on every single turbine at a wind site every few years. In fact, it has proven unnecessary when using high-quality, balanced lubricant formulation. The key is choosing a properly formulated lubricant for each turbine. With so many lubricants available today, how can you know if you’ve chosen a quality product? Here are the top five indicators of a quality gearbox lubricant. 1. Look for anti-foam properties One of the best indicators of a high-quality lubricant is one with excellent anti-foam properties. When gear oil encounters challenges such as air entrainment, incompatible oil mixing, or water, excessive foaming can result. Too much foam may lead to premature wear and gearbox failure. Wind operators can expect a small amount of air entrainment during gearbox operation. However, when a turbine is shutdown for maintenance, the accumulation of entrained air or foam should dissipate after about 15

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minutes. This means that by the time a wind technician has safely climbed uptower for an inspection, the gearbox should be foam-free. If it fails to pass the foam-free test, consider switching lubricants during the next scheduled oil change.

A wind tech sprays down the high-speed helical section of a wind-turbine gearbox during a routine maintenance visit.


2. Choose solids-free additives Look for gear oil that is blended with a balanced formulation. This means that if additives are included in the formula to resist water, foaming, and wear, this formula must remain balanced. For example, many lubricants leverage a silicone-based additive to prevent foaming. However, because of its attraction to an oil water interface, silicone particles are more likely to be caught in the filter. Certain additives may be filtered out, but this can also subject gearboxes to foaming, micropitting, sludge buildup, or scuffing wear. Micropitting is a common challenge for wind operators, which can form on surface-hardened gears within the first several hours of operation if the gearbox is not properly lubricated. A better option is a solids-free lubricant, which has proven to stand up to years of use and ultrafine filtration without depleting important additives or requiring


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costly top-treating procedures. Additive top treating gearbox oil is one way wind maintenance teams have tried to mitigate lubricant degradation and extend oil life. The concern with top treating is it may introduce new contaminants or throw off the oil formulation balance, which could impact gearbox performance. Choosing solids-free lubricant from the factory fill is the best way to extend the lifespan of gearboxes and maximize turbine production and profits. 3. Consider water resistance Water is a critical contaminant in a windturbine gearbox. Even small amounts can shorten gear, bearing, and oil life. Excess water in a gearbox can result in water attaching to additives, and clogging up the filter. This may lead to insufficient additive levels in the oil and can aggravate or increase lubricant foaming, ultimately leading to poor performance or turbine downtime. The wind industry typically use the Cantley formula, which posits that when oil contains 100 parts per million (ppm) water, users can expect to get 100% bearing fatigue life. If oil absorbs higher amounts of water, research shows that bearing life is shortened, which negatively impacts energy production and gearbox lifespan. 4. Remember the filter Many turbines are equipped with very fine filterability capabilities, which are essential for overall gearbox health. Oil filters require changing about every six to 12 months when using a quality lubricant. Lower-quality lubricants may clog filters faster, requiring new filters every three months or so and may reduce the lifespan of a turbine. This is a costly task and an inefficient maintenance program. Filter media size should play a role in lubricant choice. Most typical OEM industry standard filter media is 10 microns, but many oils fail to perform optimally with this filter size. For example, some additives, such as silicone anti-foam, may become stuck in the filter and subsequently be removed from the lubricant. Siliconeâ&#x20AC;&#x2122;s attraction to oil water interface can lead to accelerated filtration removal of silicone additives.

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For improved performance and equipment lifespan, choose a lubricant that recommends 5 to 10-micron filters for full-flow inline applications, and 3-micron filters for fine offline filtration. An oil that can handle finer filtration without compromising its quality or lifespan is ideal and will provide lower contamination levels and increased performance. 5. Buy American When a lubricant is certified, “Made in the United States,” it typically ensures the product offers quality ingredients without mysterious additives or fillers that can clog filters, slow turbine performance, or impact production. Buying local also supports the wind industry in America. When you invest in quality lubricants, you’ll generally see superior performance for the entire lifespan of your infrastructure while cutting operational costs. That sounds like a win-win. W

Nearly a decade ago, AMSOIL launched a lubricant with notable staying power that features nine years of hands-free runtime. This means after the initial fill, zero oil changes, additional filtration, water-reduction treatments, or additive top treats have been required. If using a quality gearbox lubricant, the oil filters will require changing about every six to 12 months. Here a filter is undergoing removal from the filter housing.

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4/18/18 4:16 PM


Martin Armson Vice President Hansford Sensors

How vibration monitoring improves turbine uptime For wind-turbine applications like this one, low-frequency accelerometers are the ideal choice for detecting anomalies. In general, the models used are 100 mV/g, or the higher sensitivity 250 or even 500 mV/g.


he wind industry is booming. Recent estimates put its global capacity at over 340,000 wind turbines with a generation capacity of more than 430 GW, a figure that may quadruple by 2030. But itâ&#x20AC;&#x2122;s also a highly demanding sector. While wind turbines perform under punishing conditions, operators are under pressure to run as efficiently as possible by raising output and controlling costs. One key to that goal will be preventing unscheduled downtime from component failures. Recent instances tell of wind turbines exploding from gear failures, typically from high winds. After operators pay the repair bills, they could be slapped with fines and demand for compensation. An enhanced maintenance and monitoring regime can help to cut these risks and costs. One of the most reliable techniques: vibration monitoring. Here, the vibration â&#x20AC;&#x2DC;signatureâ&#x20AC;&#x2122; of bearings and other moving parts is monitored using vibration sensors or accelerometers. Any variation from a norm can indicate early signs of failure, which allows fixing small problems before they turn into big ones.


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Downtime costs Unscheduled downtime affects more than just the wind industry. According to a joint survey from MRO magazine Plant and ARC Advisory Group, downtime costs global process industries around $20 billion every year. The survey reported that nearly 90% of all companies use predictive maintenance to increase uptime. In addition, more than half wanted to use predictive maintenance techniques and processes to cut maintenance and overall operational expenses. Among its conclusions, the survey recommends integrating predictive maintenance with plant-wide control systems, and linking the operation and outcomes of such systems to financial incentives for plant operators. It makes a strong case for using such systems, particularly in wind energy where maintenance is challenging and costly, and operators are under pressure to maximize efficiency and productivity. While predictive maintenance has advantages, there are historical factors to overcome. Many engineers have genuinely considered it cheaper to continue running with worn equipment rather

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than invest in expensive replacements. However, when considering the costs of catastrophic failure, this run-to-break theory is significantly flawed. Machines that begin to exhibit defects are at greater risk of failure than those without defects, and are more likely to generate unwelcome downtime costs. In contrast, a condition-monitoring system helps plan maintenance and replace defective components before problems occur. Sensor installation There are two main types of industrial accelerometers: AC accelerometers and 4 to 20-mA accelerometers. AC accelerometers are typically used with data collectors for the vibration monitoring of more critical or complex machines, such as gearboxes and turbines. This makes the sensors well suited for wind turbines. In general, 4 to 20-mA sensors are used with PLCs to measure lower value assets such as pumps and motors. The latest vibration-monitoring sensors operate over a wide temperature range, measuring high and low frequencies – with low-hysteresis characteristics and high levels of accuracy. Because of the punishing conditions they must withstand, the sensors offer reliable service in part due to stainless steel housings that prevent the ingress of moisture, dust, oils, and other contaminants. Accelerometers can be mounted on casings to measure the vibrations of the casing, or to measure the radial and axial vibration of rotating shafts, or both. A typical approach is to examine the individual frequencies in a signal that correspond to certain mechanical components or types of malfunction – such as shaft imbalance or misalignment – so that data analysis can identify the location and nature of a given problem. A typical example would be a rolling-element bearing that exhibits increasing vibration signals at specific frequencies as wear increases.

or fitting restrictions, and environmental conditions. It’s best to work closely with a supplier that has appropriate industry experience and knowledge. For wind-turbine applications, lowfrequency accelerometers are the ideal choice for detecting anomalies. In general, the models used on wind turbines are 100 mV/g, or the higher sensitivity 250 or even 500 mV/g. These might be used to monitor the low-speed aspects of the generator such as output shafts. Such sensors will identify faults and predict failures before they get out of control. Most turbines failures are caused by gearbox problems, such as bearing wear, shaft misalignment, and gear fatigue. Accelerometers are normally used on the main shaft that connects the rotor to the gearbox, and on intermediate speed gearbox shafts to monitor low-speed vibration. Frequencies there are low, typically between 0.1 and 10 kHz, with small acceleration amplitudes. Using a predictive-maintenance regime based on vibration monitoring, operators can reduce catastrophic breakdowns,

boost turbine availability, and increase the economic viability of wind energy. And they can start to make a dent in that $20 billion annual maintenance bill. W

Vibration sensors like the Hansford Sensors HS-100 are used in many wind projects. Most required the use of a local junction box to house the accelerometer cabling at the top of the turbine. This is usually fed back down to the ground using multi-core screened twisted pair cable to connect it to an online monitoring system. This lets operators monitor turbine conditions in real time, using a handheld device with internet access.

The typical vibration monitoring signature shows acceleration over time, from an AC output accelerometer.

Vibration specification To specify a vibration accelerometer correctly, consider the vibration level and frequency range to be measured, weight APRIL 2018

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S O F T WA R E Michelle Froese Senior Editor Windpower Engineering & Development

Simulating offshore wind projects & logistics for better ROIs

MAINTSYS and SIMSTALL are two design and maintenance tools built on Shorelines’ advanced Shoresim simulation platform, which simulate the sequence of offshore project development and O&M to determine the best course of action at each stage of a project’s lifecycle. SIMSTALL simulates a full scope of offshore project construction, including port operations, logistics, installation, commissioning, and testing. MAINTSYS analyzes operations and maintenance, and marine logistics for offshore wind farms.


he days of trial and error are largely behind us. Modeling and simulation software has made investments in new wind projects far less risky. Advances in such software improves the confidence of OEMs, wind developers, financiers, and operators because they can simulate and then analyze the entire lifecycle of a proposed wind farm from its early stages of Offshore wind costs are project planning through O&M higher than onshore and all the way to decommissioning. and the projects pose Simulation greater risks. software lets engineering, construction, and operations teams explore turbine design trade-offs, simulate siting strategies, mitigate environmental and construction risks, predict 4 6 WINDPOWER ENGINEERING & DEVELOPMENT

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component maintenance, and — perhaps most importantly — estimate production and the return on investment (ROI). In the offshore wind sector, this capability is critical to project success. Offshore wind costs have dropped, but in the U.S. they are still about twice that of onshore projects. “Offshore wind costs are higher than onshore and the projects pose greater risks to developers, construction crews, and maintenance teams because of marine conditions and logistical challenges,” says Michael Bjerrum CCO and Partner of Shoreline AS. Norwegian-based Shoreline provides verified and proven cloud-based simulation software and consulting for the offshore wind industry. “However, it is now possible to not only evaluate how a certain turbine model may measure up over time offshore but also assess different logistics scenarios prior to the start of construction. Simulation software can reduce offshore risks and project costs significantly.”

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Logistics can also have considerable impact on the profitability of a wind farm, with a share of up to 20% of total project costs. By first simulating different scenarios, however, it is possible to compare alternative ports, vessels, maritime logistics, and to identify potential safety concerns, bottlenecks, and delays. “For example, our simulation engine Shoresim can model all types of vessels, helicopters, technicians, and wind turbines on an individual level, defining attributes and movements object by object,” he says. It makes sense to model a transport vessel’s capability and route, or a turbine’s projected power output (Shoreline Simulation includes a detailed vessel and turbine database). Bjerrum points out that a crane simulation may be just as important, and particularly as a safety precaution. “Just imagine: before ever visiting a site to do his or her job, a crane driver can now track and physically model the site and his or her anticipated movements onsite. The simulation provides a virtual heads’ up and practice before doing the job — thereby reducing risk.” He adds there are even simulation models of the transition pieces that make up a turbine tower, so a wind tech can practice how to access that turbine prior to actual construction or maintenance offshore. “We model each and every element of a project, including the turbines, foundations, vessels, ports, technicians — yes, even each person is assessed.” Bjerrum says this is important to determine how many technicians and vessels will be required for each offshore activity, and the costs. A user can produce a detailed model that includes the patterns and skills of each technician. “It is possible to run many potential scenarios, or what we call ’sensitivities,’ to determine the best course of action for a project.” One such sensitivity could be something as seemingly random as the project start date. “You may be surprised how production output may vary based on the start date when inputs for historical weather data are considered in the simulation,” he says. Weather is one of APRIL 2018

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the most crucial variables in construction of an offshore wind farm. “It is also possible to input limitations — so not just what each asset or component can do but what they cannot do. For a vessel or helicopter, this can include restrictions related to wave height, wind speed, visibility, daylight, and others,” says Bjerrum.

To ease the building of a virtual wind farm, Shoreline’s SIMSTALL simulation software maintains a comprehensive input library of vessels, helicopters, ports, and wind-farm assets, all based on publicly available data. The software can simulate the full scope of offshore wind farm construction, including port operations, logistics, installation, commissioning, and testing.

Just imagine: before ever visiting a site to do his or her job, a crane driver can now track and physically model the site and his or her anticipated movements onsite. Modeling can assist answering typical questions such as, “What turbines should I choose?” or “How much downtime should I anticipate due to weather?” Shoreline’s simulations can also examine what types of agreements are ideal. “In this case, a user can consider



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different scenarios and which contract strategy may make the most sense from a cost and risk perspective,” says Bjerrum. “For instance, is it better to go with one main wind-turbine supply agreement combined with an EPCI contract for the remaining balance of plant, or multiple agreements with different companies to try and cut

Where do these simulations come from? “We’re not starting from scratch,” he says. “We have incorporated many years of European offshore wind industry experience in our simulation tools, and we continually upgrade data as it’s made publically available.” Essentially, simulation software is a data-transfer tool that lets users experiment with different available assets It is possible to run many potential scenarios, or what we call and scenarios to ’sensitivities,’ to determine the best course of action for a project. find one ideal for their project. “A digital platform costs?” An EPCI is an engineering, is a fairly cost-effective and risk-free way procurement, construction, and to transfer information and experience installation agreement. “Each decision from the marketplace to an interested user impacts a project’s bottom line, and can so that his or her experience will be as be first audited using simulations.” successful as possible,” says Bjerrum. W

Shoreline offers a Markov chain model (a sequence of possible events, the probability of which are based on past events) for generating synthetic weather time series that’s based on historical data. The model captures the uncertainty inherent in weather data, which may affect an offshore wind project’s timeline.


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Extract more value from your assets Whole-life asset optimisation improves component life, refines maintenance cycle efficacy and increases uptime to maximise turbine performance. ONYX InSight enhances your profitability by optimising asset performance. Advanced condition monitoring and predictive maintenance eliminates costly unplanned maintenance and downtime, increasing the whole life value of your key assets. At ONYX InSight, we combine engineering capability with technological expertise to transform your data into meaningful, operational insights â&#x20AC;&#x201C; all from a single technology platform.

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Michelle Froese Senior Editor Windpower Engineering & Development

Preparing turbines for lighting strikes


he average energy released in a lightning strike is 55 kWh. Understandably, most wind owners and operators breathe a sigh of relief when a major storm passes their wind farm without damage to a turbine. However, measurements have shown that lightning strikes may hold more power than initially calculated, and that large strikes can be multiples of the average. This means a powerful strike could be 20 times that of an average one. “Lightning is a serious concern for wind-farm owners,” shares Daniel J. Sylawa, Business Development Manager with Phoenix Contact. “But it is rarely discussed in detail or at length because lightning protection and management is something that’s generally considered an OEM responsibility.” Sylawa says manufacturers typically equip wind turbines with some form of basic lightning protection that uses grounding down conductors in the blades and grounding systems in the turbine. “Depending on the OEM, you’ll find different types of lightning receptors on the turbine blades, which are then connected to the nacelle via brushes or a spark gap that lets lightning conduct to a good firm ground.”



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There are over 1,700 electrical storms active throughout the world at any time producing over 100 flashes per second. This equates to some 7 to 8 million strikes per day, which means your wind farm is at risk. Preventing direct and near-strike damage to wind turbines is critical to decreasing downtime and extending reliable turbine performance.

In addition to lightning protection, surge suppression is a critical turbine safeguard that mitigates lightning or static effects. “Even without the risk of a direct strike, turbine blades rotate through the air to capture and generate energy,” he says. “Essentially turbines are large static machines, so surge protection is essential and should be found on the pitch control, tower electronics, inverter, and control system to protect against component failure.”

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miles away. In most cases, near-strike damage is invisible from the ground and may go unnoticed during routine ground-level inspections. “Lightning would be somewhat easier to manage if all strikes were centered directly on a target, but Mother Nature is much less predictable than that,” says Sylawa. “Near strikes are offshoots of lightning that can lead to serious problems — problems that may go undetected or simply not present as such for some time after striking.” One example is damage to a turbine’s blade material. A near strike may cause a small fault in the blade’s substrate material, which may go unnoticed until rain seeps in and eventually results in water damage. “When winter hits, a freeze-thaw cycle can also expand and degrade the under-grading material and lead to blade failure,” he adds. Another example is secondary lightning effects, which may cause electromagnetic pulses or surges that Near strikes can damage electronics inside a turbine There are tools available that may or substation. offer protection to a wind farm. For “I was recently in talks with one example, weather-measurement systems turbine manufacturer who is working use metrological data to predict the to increase the requirements for surge probability of a lightning strike in a given protection for their electrical system area. Lightning sensors installed at wind and components because of damage sites perform a similar function but use from secondary lightning effects. So local measurements to determine the OEMs are certainly cognizant of these location of a strike. effects and the need for high-quality surge and Essentially turbines are large static lightning protection.” Most wind-farm owners are aware of the benefits of a quality surge and lightning protection system. However, lightning risks may vary greatly from one turbine to another at a wind farm. “Unfortunately, these assets are often purchased en masse,” says Sylawa. “So unlike buying a new car where you may pick the model and specific features, buying a wind farm typically involves a less detailed selection. The developer agrees to buy a project under a set PPA with a specific number of turbines. And those may very well come from several different manufacturers.” This scenario means a windfarm operator may face challenges in optimizing a fleet. “To optimize production and ROI, a wind farm has to run as a unit. It is an electric power plant. But if one part of that plant is generating at less than full capacity or facing downtime, that puts the whole plant at risk of lost production.”

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machines, so surge protection is essential and should be found on the pitch control, tower electronics, inverter, and control system to protect against component failure. These systems may provide an extra measure of support, but they are unable to tell if a turbine is directly impacted by lightning. While a direct strike may be obvious to an O&M team, near strikes are a different story. Near strikes are indirect hits that can occur from several APRIL 2018

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Setting up safeguards Wind turbine or blade damage can occur for many reasons: wear, debris, precipitation, operational errors, manufacturing defects, lightning strikes, and others. Early detection and mitigation techniques are necessary to avoid or reduce damage. However, what happens when a near strike causes delayed onset damage such as nick in a blade that only becomes detectable over time?



North America: +1 (843) 654 7755 Europe: +49 (0) 40 / 75 10 30

4/18/18 4:23 PM

Powering Forward to Reach


The U.S. industry closed 2017 strong, delivering 7,017 megawatts (MW) of new wind power capacity. That new capacity represents $11 billion in new private investment. The wind industry is powering forward to continue growth into 2018 and beyond. WINDPOWER is where the industry comes together to plan for the future and keep this success story growing. 2018 HIGHLIGHTS • Hundreds of exhibitors & meeting rooms make it easy to meet new customers and discover the latest products and services • Opening reception is open to ALL attendees at Navy Pier, a Chicago landmark • Additional informal meet-ups added to increase networking opportunities • Opportunities to meet current and future customers grow your business • General sessions & meeting rooms will be on the show floor again • The 2018 registration list is already live – start planning your meetings now!


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Phoenix Contact Lightning Monitoring System (LM-S) use sensors based on the Faraday Effect to provide a more comprehensive range of lightning data to manage assets. Polarized light is rotated through a magnetic field over a defined length and measured. When mounted on a turbine blade’s down conductor, an external magnetic field is generated by the lightning current, which travels down the conductor and rotates a light beam proportional to the current amplitude. The LM-S lightning current measuring system can detect, evaluate, and remotely monitor lightning strikes in real-time.

“This can be a big warranty issue,” says Sylawa. “If an area had been hit by a storm, experts may try to decipher whether damage is from lightning or from workmanship and material defects. In some cases, near-strike damage cause may prove challenging to substantiate.” What can a wind-farm operator do to protect their assets and warranty? Sylawa has some suggestions. • Recognize the risk. “Most wind-farm operators opt for some type of weather service, or have some form of lightning detection.” He says the most common are direct-measurement systems such as strike counters, which are surgecounting devices, and card sensors. The card sensors attach to a turbine’s down conductor and measures the peak current that traveled down that conductor during a strike. “Ideally, an effective lightning measurement system detects a variety of risks.” APRIL 2018

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• Inspect, inspect, and inspect some more. A quality surge and lightning protection system is one key to a profitable wind farm. An excellent O&M plan is another. “There are inherent risks in operating a wind plant even with the best protection. The number one thing a wind-farm operator can do is implement high-level inspections because, at the end of the day, you cannot fully know what the effects of lightning are on turbines.” Sylawa adds that it is important to look beyond the surface of the turbine during O&M calls. “After a lightning strike, a wind tech may not find noticeable damage to the tower or blades and think everything is fine. But it’s extremely important to go through and test the electrical system. A turbine may have a tripped or blown surge suppressor that’s impossible to notice with an inspection.”

• Condition monitoring for blades. Lightning detection sensors are not new, but advanced turbine and blade lighting detection systems that connect remotely to data centers can measure and provide greater insight. For example, they can provide asset monitoring, predict maintenance issues, and send event notification — such as strike warnings. “Wind power is moving toward a smarter, more data-driven industry,” says Sylawa. “Sensors can now record information for a wind owner or operator remotely, and in seconds they’ll have access to a full analysis of what’s going on for a specific turbine or blade in that turbine.” Such data could potentially also support warranty claims. “Wind owners who have access to big data, which helps determine the health and status of their assets, will be ahead of the O&M game,” he says. W



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Vertical axis wind turbines may be the better way to augment wind-farm outputs and without the cost of conventional equipment upgrades.

K e v i n Wo l f • Chief Operating Officer Wind Harvest International (WHI)

WIND FARMS IN CALIFORNIA and other locales exist only in relatively small geographic regions.1 Most of these resource areas have reached their physical or political2 limits in their ability to install additional horizontal axis wind turbines (HAWTs).3 Nonetheless, many have topographies that create excellent near-ground wind speeds. To profit from the energetic wind below their HAWTs, wind farm owners need cost-effective vertical axis wind turbines (VAWTs) that operate efficiently in high turbulence and that do so without the wake from the added rotors negatively impacting their existing turbines. They also need turbines that are wildlife friendly. Near-ground turbulence The good-to-excellent average annual wind speeds (6 to 9 m/s, 14 to 20 mph) found at 10 to 25m above ground level in wind farms in California4 and other regions are well known to wind industry meteorologists.5 Editor’s note: This paper will be submitted for peer review to Renewable Energy Focus after receiving comments from the publication of these excerpts. Send comments and suggestions to:

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LOW-LEVEL WINDS ON EXISTING WIND FARMS substantially strengthened to withstand the high peak and cyclic loads from the nearground layer of extreme turbulence.7


Three Windstar 530G VAWTs are positioned among HAWTs in the San Gorgonio Wind Resource Area in California.

Passes and ridgelines accelerate nearground wind and cause wind shears to decrease, often significantly. Meteorological data also documents that thermal and obstacle-induced turbulence in the highenergy, near-ground wind is found in many wind farms, including in four of California’s five Wind Resource Areas. One reason near-ground wind resources have not been developed is that HAWT have increased failure rates when their blades pass through turbulence.6 As a result, rows of HAWTs are hundreds of

VAWTs could be staggered vertically and horizontally, upwind and downwind of a 2-MW HAWT.

meters downwind of each other. Just as important, the bottom tips of their blades range from 20 to 50m above ground level. The turbulence-loading problems of HAWTs arise primarily from their long blades connecting to the drive shaft at only one end, and their large rotor having to operate in winds that frequently change speed and direction. The blades and bearings used in modern HAWTs would have to be


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Why VAWTs now VAWTs are intrinsically less sensitive to turbulence than HAWTs because their blades are attached to the rotating shaft at two or more locations. Another beneficial outcome of their geometry is that VAWTs don’t have to yaw and turn into the wind’s changing direction. At least one such wind turbine (Wind Harvest International’s G168 VAWT8) is ready for certification and operation underneath HAWTs.9 Other turbines could also soon be capable of achieving a 20+ year service life in high turbulence (e.g., Stanford/Dabiri’s VAWTs), once they can comply with the IEC 61400 certification process, become UL listed, and are ready for industry-scale sales. Historically, VAWTs have had trouble with their mechanical designs and durability because they lacked the field-validated, aeroelastic modeling that HAWT engineers use. That issue has recently been resolved by WHI10 and the Technical University of Denmark - DTU. Both now have a suite of prototype-validated frequency response, aerodynamic, fatigue, and finite-element analysis models that together function as an aeroelastic model.11 The aerodynamic modeling funded by a 2010 California Energy Commission (CEC) EISG grant12 to WHI proved that modern VAWTs, placed close together would create the “coupled vortex effect”. The close spacing and counter rotations let them produce 20 to 30% more energy per pair than from two VAWTs operating farther apart. This means VAWT blades create little drag as they return into the wind. Historically, this increase in drag prevented them from realizing much more than a 40% efficiency,13 whereas HAWTs can achieve 50%. With the coupled vortex effect, VAWTs in arrays can theoretically realize the efficiencies of HAWTs. Another problem that has hindered VAWT development is that smaller VAWTs,

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such as the WHI G168, use more steel and material per rotor-swept area and megawatt of installed capacity than do large HAWTs. Now however, with large-scale use possible in wind farms: • The mass manufacturing of the smaller VAWTs offer significant savings14 • Their shorter towers and easier-tobuild foundations are less costly, and • They make dual use of valuable land and infrastructure15 when installed in existing wind farms. An additional benefit that modern inverter-based VAWTs have for repowering wind farms is that they can help solve the grid harmonics and reactive-power problems caused by older HAWTs using “induction generators”. A megawatt of VAWTs such as WHI’s G168 that use inverters like the ones Norther Power Systems uses on their 100-kW HAWTs can, independently of wind speed, instantaneously source or sink 450 KVARs16 of the problematic reactive power produced by the older HAWTs. The distances between VAWTs and their heights are described in the table Comparing densities of HAWTs to VATWs, with the exception that the G168 VAWT distance immediately upwind of the HAWT is 100m and not 70m. The faster-moving wind that is upwind and above the HAWT will be drawn down toward the ground by the vertical mixing and energy extraction of the VAWTs below.


VAWT impacts on HAWTs Aerodynamics predict that the wake from VAWTs won’t harm HAWTs, and may in fact help them. The wake and vortices shed from an array of tightly spaced VAWTs should stay in the same wind layer that passes through their vertically spinning rotors. Modeling shows that downwind by five rotor heights17 or about eight rotor diameters18, the wake of VAWTs is gone, their vortices have disintegrated, and the wind speed has recharged, in part due to the vertical mixing that their spun-off vortices create. WINDPOWER ENGINEERING & DEVELOPMENT 

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Grand Forks, ND 701.775.3000 Norwich, VT 802.649.1511 Buenos Aires, ARG + 54.11.4722.0163

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VAWT placements are theorized to increase the wind speeds entering the rotors of the HAWTs above them in the two following ways. Lowering the wind shear − A growing body of field data and research, led in large part by Dr. John O. Dabiri, has demonstrated how counter-rotating VAWTs lower wind shears by bringing higher, faster-moving wind toward the ground and replenish the wind speeds lost to the energy and turbulence the VAWTs produce.19 As a result, faster moving wind from above will drop down into HAWT rotors and increase their energy output.20 Solving the reactive-power problems of older wind farms can increase their power quality and real output. Stanford University doctoral candidate Anna Craig led a study that modeled various VAWT arrangements. Their results indicate that VAWTs can interact positively when placed in close proximity to one another. Craig noted that “We think that the VAWTs can have blockage effects causing speedup around the turbines that helps downstream turbines. They can also have vertical wind mixing in the turbine's wake region, which assists in the wind velocity recovery.” In the paper, Benefits of collocating vertical-axis and horizontal-axis wind turbines in large wind farms, the authors state, “Because of the presence of the VAWT layer, the turbulence in the wind farm is increased, which enhances the wake recovery of the HAWT. The faster wake recovery more than compensates for the additional momentum loss in the wind because of increased effective surface roughness associated with the VAWTs.”22

A row of VAWTs could be placed upwind of a HAWT at just the right height so that the HAWT blade enters a zone of higher wind speed with no significant increase in turbulence. Arrays of VAWTs placed a short distance downwind of a HAWT can also create a speed-up effect for the upwind HAWT, but the physics are different. The wind speeding up over the VAWTs decreases the pressure there, which increases the pressure difference between the front and back of the HAWT rotor. This in turn would increase the wind speed through the HAWT rotor and thus its energy output. Just how much this porous wind fence effect could benefit HAWTs was to be a significant focus of the LiDAR studies WHI proposed as part of its R&D proposal to the CEC EPIC Program.

WHI suggests the G168 as one HAWT design for increasing outputs of existing wind wind farms.

Comparing densities of HAWTs to VAWTs

Porous Wind Fence Effect − Dr. Marius Paraschivoiu’s modeling shows there will be a few meters of high turbulence directly above an array of closely spaced VAWTs. Above that, there will be a zone where wind speeds increase above ambient. This is caused by the blockage effect of the VAWTs. 58


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This 250 X 250-m square portion of the San Gorgonio Farm shows one way in which VAWTs of different heights could be placed around a newly installed 2-MW HAWT (middle, right) on a 65-m tower. In this representation, there are 428, 3-kW VAWTs, 39 WHI’s 70-kW VAWTs, and one conventional 2-MW HAWT).

VAWTs potential to increase wind farm energy output HAWTs in wind farms are placed substantial distances apart. The accompanying table compares land used in some wind farms in California’s Wind Resource Areas to other means of estimating the amount of land a HAWT wind farm needs. Modeling and field testing show that the relative distances between rows and arrays of VAWTs can be much shorter than with rows of HAWTs without the downwind row losing wind speed and energy. The table also shows the VAWT energy densities that can be developed with the following assumptions: • One-third meter between 3kW VAWTs in a four-turbine array • One meter between G168 VAWTs in a four-turbine array • Two rotor diameters (6m and 24m) between arrays in a row • Five times rotor height between G168 rows (70m) • Eight times the rotor diameter between rows of 3kW VAWTs (24m) W For further reading: 1 In 2014, WHI conducted a cursory review of wind farms around the world to evaluate them for topographies and roughness that were conducive to creating near-ground wind speed-up effects. At that time, approximately 20-25% of wind farms had the topographies, wind shears and wind speeds that should produce 15-20 mph average annual wind speeds at 10-20m above ground level. 2 The politics of zoning and permitting are influenced by concerns over views, habitat, aviation and wildlife impacts. 3 The large setback requirements needed by rows of HAWTs are well documented. New HAWTs cannot be installed within most existing wind farms without reducing the wind speeds or increasing the turbulence realized by their neighbors. 4 “Wind Energy Prospecting in Alameda and Solano, CA”, a report by PG&E to the California Energy Commission, 1980. Publicly available documentation for California’s wind resource areas is not easy to find, but all the meteorologists listed will confirm that similar wind speeds exist in Southern California’s three wind resource areas.

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5 The following wind industry meteorologists and companies will confirm that there are good to excellent average annual speeds and high turbulence in the near-ground wind in California’s Wind Resource Areas. Note that titles and associated organizations are used for identification purposes only: • Allen Becker, Consulting Meteorologist • John Bosche, President and Principal Engineer at ArcVera Renewables • Neil Kelley, Applied Meteorologist (retired) • Pep Moreno, CEO, Vortex • Ron Nierenberg, Consulting Meteorologist • Lucile Olszewski, General Manager, Ensemble Wind • Richard Simon, Consulting Meteorologist • John Wade, Senior Meteorologist, Ensemble Wind • ArcVera Renewables, Wind Prospecting and Resource Assessment • WindSim, CFD Wind Resource Assessment 6 Turbulence problems created in HAWT blades, gearboxes, and bearings HAWTs are documented in multiple places in this wind engineering textbook, “Wind Energy Explained: Theory, Design and Application,” J.F. Manwell, J.G. McGowan, A.l. Rogers; John Wiley, U of Mass Amherst, 2002.

7 David Malcolm, PhD, structural engineer, retired from Det Norske Veritas/Gemanischer Lloyd 8 WHI’s G168 VAWTs have ~168 square meters of rotor swept area and 50-70+ generators which will vary based on the wind resource. For specifications see: 9 WHI’s G168 design files have been sent to the Small Wind Certification Council, which follows the IEC 61400-2 certification requirements for small wind turbines under 100kW in size (see http:// 10 “Validation of the EOLE suite of codes for the structural response of vertical axis wind turbines,” David Malcolm. March 2017. Report to Wind Harvest International 11 WHI used a Frequency Response and Fatigue Model first created and field validated by Sandia National Labs on its Darrieus-type VAWTs. Using strain gauge data from the G168 prototype in Denmark, WHI validated the loads predicted in its Midas FEA model and these other two models. For more information on the DTU’s aeroelastic model, contact Dr. Peggy Friis at DTU. 12 “Modeling Blade Pitch and Solidity in Straight Bladed VAWTs”, Iopara Inc, Bob Thomas and Kevin Wolf, February 12,2012, Final Report to the California Energy Commission’s Energy Innovations Small Grant Program.



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13 Sandia National Labs’ field research on a Darrieustype VAWT showed it was capable of achieving a maximum of around a 42% efficiency or Cp max. See “A Retrospective of VAWT Technology”, Herbert J. Sutherland, Dale E. Berg, and Thomas D. Ashwill, SANDIA REPORT (SAND2012-0304), January 2012 14 VAWTs such as WHI’s G168 have symmetrical blades that can be inexpensively extruded or pultruded whereas the unique designs of HAWT blades don’t allow them yet to be mass manufactured. 15 For a full build-out of a wind farm’s understory, new transmission lines and substations will be needed. For a “capacity factor enhancement” project where VAWTs are added to the wind farm but turned off as the substation reaches capacity, now new transmission lines or substations are needed. 16 Reactive Power Compensation - Using a Northern Power® NPS 100TM or NPS 60TM wind turbine to manage power factor, NPS Engineering Bulletin

17 In Dr. Marius Paraschiviou’s letter to the CEC in support of WHI’s grant application, he stated “… after the CEC Innovations grant was completed, we conducted additional aerodynamic modeling on downwind wakes that showed VAWTs like WHI’s G168 will be able to be placed about six rotor heights downwind of an upwind VAWT array and realize the full wind speed that entered the rotors of the upwind array.” 18 A number of Dr. John O. Dabiri’s papers show that VAWTs as placed in their field studies can regenerate ~95% of the full wind speed at 7 rotor diameters downwind. (Kinzel M, Mulligan Q, Dabiri J., 19 Energy exchange in an array of vertical-axis wind turbines. Journal of Turbulence 2012; 13: 1–13. Note that in his field studies, Dabiri’s placement of VAWTs are as close together as they are in Paraschivoiu’s modeling. The tighter spacing and the resulting increase in wind speed in the gaps between the VAWTs that was used in Paraschivoiu’s modeling probably is the reason for the difference

20 Potential order-of-magnitude enhancement of wind farm power density via counter-rotating vertical axis wind turbine arrays. John O. Dabiri, Journal of Renewable and Sustainable Energy 3, 043104 (2011) and Benefits of Co-locating Vertical-Axis and Horizontal-Axis Wind Turbines in Large Wind Farms. 21. The energy in the wind is the cube of the wind speed so a small increase in wind speed results in a significant increase in the energy.

The Power Behind the Power You bring us your toughest challenges. We bring you unrivaled technical support. Superior engineering. Manufacturing expertise.

Power on with innovations developed from the inside out. Visit us at Booth 3620 at WINDPOWER 2018

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improved foundations

wind industry needs





INDUSTRY has its roots in the oil and gas industry, along with developments from Europe’s offshore wind industry. This combination has produced our first offshore wind farm near Block Island, Rhode Island, but at a staggering cost of $50 million per turbine. Costs must come down for the U.S. offshore industry to grow. That means it is time to put down innovative roots that offer significant cost reductions.

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Andy Filak • Principal • AMFConcepts One way for offshore wind developers to lower installation and operations costs is to look for manufactures and marine installation companies that offer innovative technologies. One way would be to eliminate costly steel foundations for offshore turbines. Saltwater is high in oxygen making it naturally corrosive to steel. Cathodic protection (CA) is necessary to safeguard steel foundations from erosion. The cost of a CA system requires regular monitoring, periodic maintenance, a reliable external power source, and methods for detecting stray current interference. Using new materials that do not require CA may lead to faster and less costly construction and deployment methods. In addition, installation companies must call for the design of new vessels that allow manufacturing turbine foundations on board and provide for their deployment. These new, self-powered oceangoing deck barges will have catamaran hulls with dynamic positioning, and rudderless azimuth propulsion units with forward-mounted side thrusters on each hull. Furthermore, active heave compensation will make it easier to deploy the foundations and mount fully assembled and commissioned wind turbines. These vessels will reduce the typical high-day rates and residency time of O&G deployment vessels.



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wind industry needs

improved foundations

Better ideas for fixed & floating foundations One hurdle to offshore wind development in the U.S. has been designing a reliable, inexpensive, long-life foundation that would be relatively easy to build and install. Existing steel technology requires highly complicated shore-side construction and at-sea installation procedures with multiple large crane vessels and anchor handling tugs. Such challenges may be solved with these few improvements:

Wind turbine concrete jacket support fixed to sea bed

â&#x20AC;˘ Advances in composite concrete ideal for marine use â&#x20AC;˘ A new formwork method for manufacturing foundations â&#x20AC;˘ A catamaran ocean-going deck barge for construction and deployment. Meeting the challenges is possible thanks to four significant developments. 1. Omitting the Ordinary Portland Cement (OPC) binder in the composite concrete. 2. Replacing the coated-steel rebar with a non-metallic material that will provide a stronger reinforced structural frame. This material includes a cut basalt fiber and high-strength aggregates that make for a high-strength geopolymer concrete mix. Basalt rebar (see definition below) can develop high-strength concrete in tension without a lot of cover or concrete over it. 3. Placing the foundations in a completely novel way (the catamaran deck barge). 4. Replacing the steel-foundation piles with those made of epoxy-basalt fibers that have the same strength as steel. This combination of advances will increase the longevity of the foundations while simultaneously reducing construction and installation costs. Novel deck barge & new materials The new construction and deployment process for deep-water foundations described here allows erecting a wind turbine for a fraction of the current 62


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The jacket foundation would be made of a geopolymer with basalt rebar giving it a lifespan that would allow supporting several generations of wind turbines.

foundation cost. Why? Because the foundations are constructed on a deck barge while it is tied to the quay, saving offshore costs. The barge is then powered out by its own propulsion to the wind farm for deployment. The greatest threat to existing marine concrete is water, either fresh or salt. With time, water penetrates concrete through unseen cracks and material porosity, and

rusts the rebar skeleton. Even proactive rebar has coating failures and deterioration that eventually corrodes the steel. Seawater also directly attacks the chemistry of OPC, causing rapid deterioration. The OPC binder fails at sea because of its high percentage of calcium compounds. About 70% of the binder comes under attack by the sulfur compounds in saltwater. It essentially

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rots the concrete. The cement binder in a concrete mix design can occupy up to 20% of the concrete mass. A more advanced mixture replaces the OPC cement binder in the concrete mix with a geopolymer binder to foil this degradation scenario by minimizing the calcium compounds. Geopolymer cement binders are used commercially for their superior performance over OPC binders. Geopolymers produce a saltwaterresistant material that is stronger, fireproof, and waterproof. Geopolymer binders are formable, bond well to most materials, have minimal expansion or contraction, and are resistant to salts, acids, and alkalis. This will ensure the new foundation substructures will have a minimum of a 100-year life due to their low porosity, high-strength, and heat and dry-cured technology. Basalt rebar is made from basalt stone found all over the earth. Basalt is a key component enabling the hundred-year minimum durability of the foundation structure. Heating basalt stone to 1,800°F liquefies it, so it can be run through a palladium die to produce soft flexible fibers or threads. The threads are laid in parallel and bonded together with an epoxy, to produce basalt rebar and basalt foundation pilings. To select a formwork system, a wide variety used globally were studied. Slip forming (like a slow extrusion) is the only method to show significant promise in reducing costs and production timelines for three proposed foundations systems (two fixed and one floating). Analysis shows that it is less costly to build smaller jackets than to build steel monopile foundations. The proposed formwork system produces the most cost-effective solution. The heat curing formwork can achieve a two-footper-hour slip. The formwork allows completing any of the three possible foundation systems in under seven days each. Slipping the foundations uses standard methods except for the heated formwork and the trunk placement of the geopolymer concrete. APRIL 2018

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Construction platform & deployment vessel It is typically too costly to slip-form the foundations on land and lift them onto a vessel. Therefore, it is necessary to develop a self-propelled catamaran barge. To simplify the overall process, the deck barge serves as a construction platform, transport vessel, and deployment platform all in one. Foundations would be slip-formed at each end of the barge, in front of and behind the mid-ship structure of the bridge castle, while it is moored to the quay with ready access to materials and resources.

Upon completing the onboard construction of two foundation substructures, the barge would power out by its own propulsion to the wind-farm site. At the site, the barge dynamically positions the foundation over the pre-pile center with the azimuth propulsion unit and forward side thrusters on each hull. The foundation is then lowered with its four-active heave compensation units supporting high-capacity synthetic cables, from linear winches over a sheave to four lift points on the foundation. Once over

Jackets can be slip formed to handle installations in water depths from 20 to 50m. The floating spar buoy foundation would work in water depths greater than 50m.



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wind industry needs

improved foundations the piles, the foundation is lowered to mud mats (large pads) on the seabed, where the foundation is leveled and grouted. By using this method, construction and installation costs are a fraction of current steel foundations because there is no need for tow-out tugs, anchor-handling tugs, or specialized heavy-lift crane vessels. Such new foundations can be installed on a wide range of seafloor conditions, including sand and rock. Foundations can be anchored by driven or drilled piles or, depending on the correct soil, by suction buckets. To maintain a 100-year life goal, fiber (basalt) glass would be used on piles and suction buckets. The fiberglass is one fourth the weight of steel and of equal strength. The piles, produced in 100-foot lengths, allow for greater energy absorption than steel, and work well with underwater vibration and air-hammer placement. No more monopiles The offshore wind industry in Europe is placing 6-MW turbines on monopiles in 40-m deep water. This is pushing up the cost of a monopile.

The top left image shows a crosssection of the top of the jacket on which a transition would mount. The bottom cross-section is a five-ft high starter section for a jacket. It would be built on the deck of the deployment vessel with conventional steel formwork.


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Rather than producing an individual design for each depth, the offshore industry in the U.S. needs a way to produce jackets and adjust them for all water depths from 20 to 50m. Floating offshore wind turbines are essential to meet the challenge between the fixed foundations in up to 50m depths and floating platforms in over 50m. The steel spar buoy is too costly to produce, transport, and deploy in deep water. Deployment also includes up-ending and placing ballast, the cost to mount the WTG, and then transport the assembly to the wind farm. All this requires several vessels and tugs with high day rates and long periods on station. However, by slip-forming the spar buoy on the barge described, it can all be done more efficiently on one vessel. Considerations for decommissioning The 100-year minimum life of the foundation systems is key to supporting three generations of wind turbines, and will play a role in decommissioning. The decommission deposit, required at the start of the wind-farm lease, could be smaller due to their long-term earning potential. The Bureau of Ocean Energy Management Regulation and Enforcement estimates the cost of decommissioning at 60% of the total estimated construction cost of the WTG in the wind farm. Decommissioning, required within two years after termination of a wind-farm lease, calls for removing all facilities 15-ft below the mud line. This will include the turbine, foundation structures, pipelines, cable and other structures and obstructions. The requirements are similar to O&G offshore site cleanup. Decommission bonds are aimed at reducing, not eliminating, potential later financial liability. Most bond levels are set at three times the expected cost. The productâ&#x20AC;&#x2122;s 100-year life could reduce these bond level requirements. The cost of decommissioning could be substantially reduced by using the same type of vessel that originally deployed them. W

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to Windpower Engineering & Development’s Innovators and Influencers of 2018

Success has many parents says and update of the old saying, and the wind industry is no different. On the next few pages you will some of those who had the inspiration to tackle the technical problems unique to the wind industry. These innovators and influencers have had such a significant impact on the wind industry that the staff of Windpower Engineering & Development would like to recognize and celebrate their success in this Ninth Annual Innovators and Influencers special section.


I N N OVATO R » Ro b B u d ny –

Taking gadgets and appliances apart to see how they functioned is something that Rob Budny enjoyed doing since he was a kid. Budny is currently the Chief Reliability Officer and a Co-founder at Ensemble Energy, a predictive analytics company. He previously served as the President at RBB Engineering, a consulting firm that provides rotatingmachinery engineering services. The firm’s largest sector served is wind (think gears, bearings, and gearboxes). “I was a very curious child,” Budny shared. “I always wondered why things were done in certain ways, and how they could be done better. I loved taking things apart, and eventually my mom had to start placing her kitchen appliances in places that I couldn’t reach because when I took things apart, I didn’t always put them back together correctly.” That did little to deter Budny, and it was no surprise when he decided to earn a bachelor’s degree in Mechanical Engineering from the University of Maryland, or began his career in the aerospace industry. He started as a design engineer and stress and fatigue analyst for Lockheed-Martin and Northrop Grumman. In 2005, he switched fields and worked his way up to manager of mechanical engineering at APRIL 2018

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Chief Reliability Officer & Co-founder of Ensemble Energy

a large wind-turbine manufacturer. Until 2013, when he launched RBB Engineering, Budny designed and engineered turbine components, such as the generator, gearbox, and pitch and yaw systems. “I grew up idolizing my grandfather, who was a diesel mechanic, carpenter, and the smartest person I ever knew,” said Budny. “He inspired me to become an engineer, and I’m grateful for that. Wind is such an interdisciplinary sector. To fully understanding how turbines work and make them operate better, it is important to gain knowledge of aerodynamics, mechanical engineering, electrical engineering, materials, and computer science.” Budny also credits his dad for his curiosity and ambition to learn. “My dad worked in the Air force, so I grew up overseas in places such as Turkey, Germany, and the Philippines. My imagination was spurred, I think, by living in so many places that were so different in many ways,” he said. His imagination and a good measure of determination, further spurred Budny to develop and launch predictive analytics company, Ensemble Energy, with co-founder Dr. Sandeep Gupta. Gupta is a 15-year wind veteran and expert on turbine controls, loads

analysis, and performance optimization. “The main challenges for wind operators today are increasing operational efficiency, reducing O&M costs, and increasing energy production. As the wind industry matures, these goals become increasingly difficult to obtain. We thought we could help,” he said. Ensemble Energy uses advanced machine-learning algorithms to improve the efficiency and production of wind farms, a feature that impressed a team of wind judges at AWEA’s annual O&M and Safety Conference in San Diego in late February. At the event, AWEA held its own version of the reality TV series, Shark Tank, where entrepreneurs are given a chance to present their ideas for venture capital. AWEA’s version focused on wind analytics developers, and Ensemble Energy took home the win. “The response from the wind industry has been outstanding, and our Shark Tank win provides further validation and confirmation of the value of our approach,” said Budny. “Gupta and I believe that combining machine learning and artificial intelligence with windturbine expertise is key to increasing windfarm efficiencies and required for the wind industry to grow and thrive.” W WINDPOWER ENGINEERING & DEVELOPMENT  


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I N N OVATO R » D r. Ja m e s Walker – Founder of the American Wind Wildlife Institute

While working in the Nixon-Ford Whitehouse during the Arab oil embargo in the 1970s, Dr. James Walker was tasked with identifying new and innovative energy technologies that could take the bite out of the embargo. “We considered nuclear, geothermal, biomass, solar, and wind,” says Walker. “We also knew only one or two technologies would be serious contenders. Solar was too costly at the time. Wind power, however, produced zero emissions and used no water for cooling, so it seemed the winner. Later, I realized how exciting it could be when I co-hosted the first International Wind Energy conference in 1981 in Palm Springs, California.” After the conference, Jim Dehlsen (founder of Zond and Clipper) who was thinking about forming a solar company, decided wind power was the place to be. “I visited him sometime later when he was Zond CEO. Out his office window, you could see row upon row of wind turbines. A little meter on his desk reported the production of that fleet in kilowatt-hours. That little meter told me the wind industry can produce power and make money,” says Walker. As it is now, California was eager to find clean-power replacements for its legacy plants. But what would it be like finding useful sites in other countries? Eventually, Walker wound up in Greece and responsible for finding good wind sites there. The advice he received suggested locating the town dumps because it was typically land uncared for and there would be little opposition. The villages also put the dumps in windy areas to 66


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clear out any odors. “That turned out to be surprisingly useful advice,” he says. A competitive nature has also served him well. While president of AWEA in 2009, he read many reports saying Germany was the top wind-power producer in the world. Soon after that, the Chinese were said to be tops. But the rankings were all based on installed capacity. “This did not help each time we went to Congress for support because they saw the same numbers. There, we were criticized for being unpredictable, unreliable, and we got no credit for past success. Why were we measuring installed capacity when production in megawatthours makes more sense?” Shortly thereafter, he read a figure for wind-power production in Germany, and it was less than U.S. production. Finding a figure from China was more difficult because their Energy Ministry publications were not as easily available. However, one group of advocates found the elusive MWhour-figure. “As we expected, the output of the U.S. wind-power industry exceeded those other two countries. Either one may have more turbines, but they also had half the capacity factor, about 16%. In the U.S. it’s about 31%. What’s more, companies in China were paid for what they installed, not production,” says Walker. This finding let President Obama to declare in his 2015 State of the union message that “America is number one in wind energy.” Walker played an influential role in the development of long term plans for the wind industry. With the DOE, national labs, and AWEA he collaborated on

two major reports which demonstrated that a lot of wind energy could be developed with great net benefits for the nation. That has led to a solid basis for setting goals of getting 20% of the nation’s electric generation by 2030 and 35% by 2050. “Initially, even some industry leaders were uncomfortable with such challenging targets, but now they are seen as doable primarily due to the dramatic drop in the cost of wind generation and supportive policies, mainly at the state level, and demand from corporate buyers,” he said. But Walker says the achievement he is most proud of is the founding of the American Wind Wildlife Institute (AWWI), a non-profit organization made of the wind industry and conservation science organizations devoted to conserving wildlife around the development of the wind industry. “Today the Institute stands for the combination of the power of science with the voice of collaboration to facilitate wind-energy development and wildlife conservation.” Others agree. “James is a visionary,” says Abby Arnold, AWWI Executive Director. “He recognized that it is in the wind industry’s interest to invest in understanding its risk on wildlife and develop solutions that address wildlife issues so we can sustainably grow the wind industry. We are celebrating the Institute’s 10th anniversary and because of his leadership and visionary thinking, we have made considerable progress understanding risk and developing solutions to address it.” W

APRIL 2018

4/18/18 4:36 PM


INFLUENCER » Kr i s te n G ra f –

Kristen Graf is a self-professed math and science nerd who loves puzzles, and is currently the Executive Director of Women of Renewable Industries and Sustainable Energy or WRISE (formerly Women of Wind Energy or WoWE). “I believe climate change is among one of the great puzzles and opportunities of our time,” she says. “And in order to solve and innovate for it, we need as many great minds, ideas, and perspectives as we can get to the table.” For Graf, this includes women and minorities. In the wind and solar industries, only about 20 to 30% of workers in the U.S. are currently women. “Over the last few years, figures have hovered in the upper half of that range, but it’s frustrating. If you dig, you’ll learn than women of color represent only a small fraction of that total and are sorely lacking in wind tech and solar installer roles, as well as in executive roles and on boards.” Considering WRISE (then called Women of the Wind) launched in 2005 — when three founders first decided to create an organization that supported women in wind power — and it’s now 2018, there’s still much equality work to be done. However, Graf and her team at WRISE have worked tirelessly for over a decade to bring gender and diversity awareness to the renewables sector. “We’ve been working for years to showcase the data that makes the case APRIL 2018

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Executive Director of WRISE

Degree in Agricultural and Biological for diverse teams, and it’s slowly paying Engineering from Cornell University. At off,” says Graf. “Now many leading the time, she worked for the Cornell companies want to be involved in this Cooperative Extension, assisting in efforts mission. In fact, quite a few are actively to expand the role of renewable energy in working on their own cultures and agriculture around New York State. internal policies to figure out how to gain Graf was also an active member and advance diverse talent.” of the Executive Team of the Cornell Last summer, the organization University Chapter of the Society of officially broadened its scope (hence the Women Engineers. name change to WRISE) to include wind “I’m inspired every day by the hardas well as solar power, energy storage, working, determined people I get to energy efficiency, energy management, and power marketers focused on renewables, I believe climate change is among one of transmission, distributed the great puzzles and opportunities of our generation, and smart grid technologies. time. And in order to solve and innovate “The energy sector for it, we need as many great minds, ideas, is growing and it’s and perspectives as we can get to the table. important we grow with it,” explains Graf. meet all over the country who care “Despite some progress, the real work deeply about accelerating the transition is just beginning and we have a lot of to renewables. Many are demanding a opportunities to make significant changes seat at the decision-making tables to talk in the years ahead. Fortunately, WRISE clean energy, but are also now looking has also built a tight-knit community of for diverse perspectives to join in the women that is working to support and conversation.” advance each member personally and Graf says it’s a privilege to see professionally.” changes, even small ones, and she’s In 2013, Graf was recognized for her proud to be part of the efforts for greater work with WRISE, and given the Award diversity in renewables. “If we continue to for Mid-Career Achievement in Mentoring support the community and do it well, it and Education by the U.S. Department will mean a more welcoming industry for of Energy’s C3E Initiative. As a true everyone — including all women.” W science nerd, she earned a Bachelors



4/18/18 4:38 PM


I N N OVATO R » Jose p h Sav ino –

NASA engineer and scientist

Editor’s Note: To learn more about pioneering work in wind turbines and NASA Glenn’s (then Lewis) contributions visit

Success has many fathers, goes the old saw. And so it is with the wind industry. There is official history and then there is the sometimes more interesting nonofficial history, you know, real life. First, we present an official version of one genuine pioneer of wind energy. NASA files say that in the 1970s, Dr. Joseph Savino tackled a task presented by the Agency and the National Science Foundation to prepare a feasibility study on wind turbine technology as an alternative power-generating industry. Savino accepted the job and the results generated sufficient interest that led to the U.S. hosting a Wind Energy Workshop, which drew worldwide interest. When last interviewed at 76, Savino had become an advocate for the advancement of wind energy as a growth industry in Northeast Ohio. “Little literature was available on wind turbines then, but the Glenn Library was indispensable in aiding my research,” Savino said for a NASA publication. “The outcome was key to the center leading the U.S. Wind Energy Program from 1973 to 1985 for large horizontal-axis wind turbines, the most widely used systems.” While there have been many technologies adopted from that era for energy application, Savino was convinced still more exist across the agency that had yet to be introduced to the market. To find the hidden technology, Savino contacted his protégée, Dr. Larry Viterna, to mount support from NASA to help 68


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make wind energy a significant part of Ohio’s electricity portfolio. Viterna, who was Glenn’s lead for Strategy and Business Development, shared an office with Savino and led the Wind Energy Program Office’s aerodynamics team from 1978 to 1981. “Joe was the catalyst for NASA meeting and consulting with regional leaders to promote wind energy as a viable industry for Ohio. He has been an inspiration to me and key to my involvement, as well as the center’s,” Viterna said in an earlier interview. He added that it was Savino’s motivation that Viterna made a chance discovery that a model he had coauthored for predicting wind turbine power had become something of a universal standard. In addition, Dr. Erwin Zaretsky, a scientist who worked with Savino, says Savino saw the possibility of wind power in the 1970s and petitioned NASA Lewis (at the time, it’s now NASA Glenn) for funds to pursue the building of a couple wind turbines. But after having a grant proposal accepted, he found that building a working model was going to be more expensive than expected. The gearbox, for instance, was quoted at about $60,000, much more than was budgeted. But after a discussion

A MOD-2 Turbine, one of the 13 experimental turbines, funded by the NSF and Department of Energy, that were put in operation between 1975 and 1979. NASA and Savino eventually built a 4.2-MW wind turbine, with a 79-m two-blade rotor and 80-m hub height.

with Cleveland-based gearbox manufacturing Horseberger and Scott, the company offered a unit that a customer has refused delivery on. Savino and team could have it for $20,000. He took it and on something of a shoestring budget, built a wind turbine on which most of today’s utility scale turbines are modeled. Zaretsky says that Savino’s design confirmed the potential of wind power. NASA, Savino, and Viterna went on to build four wind turbines at the Plum Brook Station in Ohio. The largest of which was rated at four-megawatts, which stood at the largest for at least 25 years. Savino’s contributions to wind energy and other notable efforts over his 41 years of service to NASA was recognized during a ceremony for the Outstanding Mechanical Engineer Award presented by Purdue University’s School of Mechanical Engineering. Savino earned three mechanical engineering degrees from Purdue University: a bachelor’s in 1952, a master’s in 1953, and a doctor of philosophy in 1955, all before joining the staff at NACA/NASA in the summer of 1955. Savino died in 2012. W

APRIL 2018

4/18/18 4:41 PM


I N N OVATO RS » Fo u n d e r s o f Wind

H a r ve s t I n te rnat io nal

The Wind Harvest Co. founders Sam Francis, George Wagner, and Bob Thomas pose at the Windstar 480 VAWT project site, Concord, California in 1985.

It seems nothing happens fast in the wind industry and certainly, nobody does anything significant alone. Even though the recent history of the wind industry in the U.S. earnestly begins about 2000, companies like Wind Harvest International (WHI) were working to be taken seriously more than a decade before that. The original Wind Harvest Company was formed by a trio of friends with diverse backgrounds: George Wagner was an attorney and environment activist, Sam Francis was a successful painter and visionary, and Bob Thomas is an aeronautical engineer and inventor. All met at and started the company after attending a seminar on Carl Jung by Dr. James Kirsch, who was also an original investor. WHI says its mission is to offer costeffective and durable vertical-axis wind turbines (VAWTs), develop new markets for wind energy, and integrate VAWTs into wind farms to optimize land use and energy production. Here’s what each man contributed fulfilling that mission. Bob Thomas, the technical brains behind WHI’s core turbine design, managed to build and test over a dozen prototype VAWTs from 1976 to 2012. Thomas’ approach to innovation and engineering led to a series of patents that form the core of WHI technology, including the Coupled Vortex Effect. (Three patents are described here: In the early 1970s, Thomas recognized the need for effective renewable-energy technology and applied his engineering experience from the aerospace industry. At the time, Thomas envisioned a wind APRIL 2018

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industry that combed government incentives, investment support, and technological innovation. As head of the California Wind Energy program in the early 1980s, he helped enact this vision and facilitate commercialscale wind farming in California. Thomas headed an early wind energy program for the U.S. Air Force and later worked for the California Energy Commission. Author Peter Asmus (in his book, “Reaping the Wind”) calls Thomas the father of the U.S. wind industry because of Thomas’ role as manager of the Commission’s wind program. Thomas also helped move Gov. Brown from supporting the large (and failed) Boeingdesigned HAWTs of the late 1970s to the small turbines such as those from Kennetech, Flowind, and Jacobs. The development boom that got the U.S. and global wind industry off the ground with thousands of turbine installations may have never happened without him. “I think Bob’s greatest invention will be the Coupled Vortex Effect,” said WHI’s current COO Kevin Wolf. “When Dr. Ion Paraschivoiu was hired to use the data from a three-VAWT array in Palm Springs to model the effect, he said it was something neither he, engineers at Sandia National Labs, nor anyone else had considered.” French-wind-turbine company, Nenuphar, says the vortex effect will be key to floating offshore VAWTs (see https://tinyurl. com/french-vawts). “This physical phenomenon can change how wind farms of the future are designed because of the vortex effect’s ability to increase the wind speed of neighboring

VAWTs and how it can change surface roughness, vertical mixing, and wind speeds downwind,” added Wolf. Thomas has a BS in Aeronautical Engineering from the University of Michigan and completed graduate work for a Masters in Environmental Engineering at UC Davis. He remains active in the WHI creative design engineering for VAWTs operating in turbulent near-ground winds and has a healthy stock of innovative ideas waiting to be tested. George Wagner served as President of WHI and major fundraiser over the course of 30 years. He established a large group of enthusiastic investors whose money, energy, and good will have kept the start-up company going in a challenging business climate. Alternative energy companies were rarely given enough support to launch an effective clean energy company. Thanks, in part, to Wagner’s confidence and perseverance, WHI succeeded. His efforts helped bring WHI’s vertical-axis wind turbines to the wind industry. Wagner died in 2015. Sam Francis was an environmentalist, visionary and internationally recognized artist. When he met Bob Thomas and George Wagner in the 1970s, Francis was fascinated with Thomas’ idea of VAWTs and how they could help reduce the world’s dependency on fossil fuels. He quickly encouraged the start of the Wind Harvest Company, and joined Thomas and Wagner as founders. Over the years, Francis became the company’s leading investor and supporter. The company logo is an adaptation of a painting Francis created for Wind Harvest. Francis died in 1994. W WINDPOWER ENGINEERING & DEVELOPMENT  


4/18/18 5:52 PM



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APRIL 2018

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Abaris Training....................................................................38 Amsoil Inc..........................................................................BC AWEA....................................................................................52 Aztec Bolting............................................ cover/corner, 31 Bronto Skylift........................................................................ 5 Castrol Optigear.......................................................... IFC, 1 Dexmet Corporation.........................................................11 EAPC..............................................................................57, 70 Elevator Industry Work Preservation Fund................... 41 HELUKABEL USA................................................................33 HYDAC International.......................................................... 2 Mankiewicz Coatings....................................................... 51 MATTRACKS.......................................................................29



Maxwell Technologies...................................................... 13 Mersen.................................................................................25 Norbar Torque Tools........................................................... 7 ONYX Insight......................................................................49 RAD Torque........................................................................27 Rotor Clip............................................................................30 Timken..........................................................................23, 60 Wanzek Construction.....................................................IBC



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4/18/18 5:36 PM

A hummingbird inspires a wind-power generator HUMMINGBIRDS POSSESS A UNIQUE SKILL that other birds do not. While most birds flap their wings up and down to fly, hummingbirds can fly right, left, up, down, backwards, and even upside down. They are also able to hover by flapping their wings in a figure-8 pattern. Hummingbirds and wind turbines may have few features in common but Anis Aouini, developer of Tunisia start-up company TYER Wind, noticed a potentially valuable connection using biomimicry. It is the practice of imitating nature to solve engineering and design challenges. When Aouini considered the movement of a hummingbird’s wings, he envisioned a wind turbine that could maximize wind flows in a similar fashion. The result: a unique biomimetic turbine that replicates the mechanical action of hummingbird wings. And yes, the design is bird and bat-friendly, and adaptable to most urban or rural environments. It works like this: The TYER wind converter harnesses wind energy using small, wing-like blades that mimic the shape and motion of hummingbird wings. Unlike conventional wind turbines that use rotating blades, the TYER essentially flaps its wings (or blades) to convert wind flows into figure-8 patterns. This lets the design capture energy on up and down strokes, maximizing power from both lift and the drag forces. TYER Wind says its technology has been simulated and modeled, and attributes development to Aouinian 3D kinematics. As the name suggests, this 3D program was developed by Anis Aouini and allows modeling the conversion of a linear action into rotational motion. The program also allows imitating animal kinematics — including hummingbird wings. An online video of an operational TYER vertical-axis prototype is showcased on the company website. The prototype’s wingspan is about 12 ft. and it produces close to 450 rpm in high winds. According to the company, the machine is currently undergoing tests that include power efficiency, aerodynamic behavior, and material resistance. Yet another possibility for the design, according to TYER Wind, is the installation of two machines at two levels on the same tower. This may result in better space optimization and a higher electrical output per square kilometer. Regardless, the TYER is branded as an “eco-friendly machine with a powerful potential of landscape integration and a limited visual impact.” Learn more at W



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Windpower Engineering & Development - APRIL 2018  

Why Adding VAWTs to a Conventional Wind Farm Makes Sense; U.S. Offshore Wind Industry Needs Improved Foundations; Powering Wind Forward at W...

Windpower Engineering & Development - APRIL 2018  

Why Adding VAWTs to a Conventional Wind Farm Makes Sense; U.S. Offshore Wind Industry Needs Improved Foundations; Powering Wind Forward at W...

Profile for wtwhmedia