Windpower Engineering & Development AUGUST 2015

August 2015 www.windpowerengineering.com

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Digital Twins and JIT training

COSTS OFF O&M Home sweet bat home PAGE 6 Goldwind 2.5 MW DD PAGE 36

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August 2015 www.windpowerengineering.com

The technical resource for wind profitability

Digital Twins and JIT training

COSTS OFF O&M Home sweet bat home PAGE 6 Goldwind 2.5 MW DD PAGE 36

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HERE’S WHAT I THINK

Editor | Windpower Engineering & Development | pdvorak@wtwhmedia.com

I hope the nuclear guys are right. In the meantime...

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Good news for the wind industry: the House of Representative late last month voted 23 to 3 to extend a series of tax credits that had expired.

The Production Tax Credit was among them.

The bill must yet pass the Senate but if most on the House Finance Committee can have their heads in the 21st century, chances are good that the Senate will also pass the bill, and hopefully with few adjustments.

Unfortunately, good news for the wind industry is automatically taken as bad news for some who have not quite transitioned to the 21st century, such as Senator Lamar Alexander from Tennessee. His state is home to the Oak Ridge National Laboratory, the government funded nuclear research center. Soon after the House action, Sen. Alexander made this comment in a statement: “Relying on windmills to produce…electricity when nuclear power is available is the energy equivalent of going to war in sailboats when nuclear ships are available.” The war analogy does not work and the Senator should be aware that windmills grind grain and pump water, but wind turbines produce power. Predictably, he goes on to say that after 22 years of (sic) billions of dollars in subsidies, wind still produces only 4% of our electricity. The Senator took the billions-of-dollars remark from wind critics bogus figuring. There is no honest calculation for it. Of course, he’s grousing about the PTC which is actually a bargain and comes with no such cost. Wind critics faulty assumption is that the wind industry grows at the same rate with or without the PTC. That is not true and was disproved in the April editorial.

The Senator further suggests the nation should build nuclear reactors instead of wind farms. He’s actually half right: We should be building small modular reactors (SMRs) powered by thorium along with wind farms

because consumers expect inexpensive power 24/7. As the EPA shutters coal fired plants, natural gas and wind will pick up demand for some time to come.

SMRs will get here, eventually. Utah’s Associated Municipal Power Systems and NuScale Power in Oregon say they are planning a 600 MW nuclear plant of 12, 50-MW SMRs. Proponents say units this size can be built in a factory for better quality control and costs theoretically will be trimmed by components purchased in volume. (The same economy of scale works in the wind industry.) The DOE awarded NuScale $217 million to support design, certification, and licensing, and hopes to unveil a working model by 2023. By that time, the wind industry will be shouldering 15% of the electric load, if predictions are right.

Speaking of billions of dollars, have you notices that when the discussion is on the wind industry, critics produce bogus and inflated cost figures to support flawed arguments? Yet when the discussion turns to nuclear power, the talk of cost disappears. If history is any guide, nuclear plants will be expensive on any scale.

Kiss your $0.065/kWh power rate goodbye, unless hefty government subsidies, detailed in the Federal budget, pick up the burden of developing working SMRs. Honestly, I hope the optimistic promises from nuclear proponents of low cost power are right because a growing world economy will need lots of power. A few million more electric vehicles would be great for generating demand.

So to end the grousing that the PTC is unfair, why not expand the tax credit to include the nuclear and gas industries along with the wind industry. For every new power plant, let the developer take the same $0.023/ kWh tax credit for 10 years. Scratch all other energy subsidies. Does that sound fair? W

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8/11/15 1:41 PM

CASTROL IS IN WIND TURBINES. BIG TIME. Throughout North America, more wind turbine gearboxes are first filled with Castrol gear oil than all other gear oils combined.

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12/11/2014 10:15 8/13/15 3:44 PM

CO NT R I BUTORS

BONNER

CLARK

LETHE

SHARMA

CHANDRABLAN

LARSEN

MAHONEY

STARR

STOUT

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WINDPOWER ENGINEERING & DEVELOPMENT

Contributors 8-15_Vs5.indd 2

RYAN BONNER is the Marketing and Training Manager for Alcoa Fastening Systems & Rings, Industrial Fasteners Division. This division produces Huck, Marson, and Recoil brand fasteners, tools, and accessories. Ryan has been with the company since 1998, and has held progressively more challenging roles within the organization, including Purchasing Mgr and Operations Mgr for AFSR’s Industrial Distribution Group. He holds a bachelors degree in Marketing & Distribution Management from Indiana University.

SANTHOSH CHANDRABALAN is the Technical Business Development Leader for 3M’s Renewable Energy Division. He leads 3M’s Wind Energy Business for North and South America and is the global technical liaison for the wind business. Chandrabalan’s background is in composites, and he is an active member of many wind/ composites communities including AWEA Operations and Maintenance focus groups. Chandrabalan holds a BS in Composites Material Engineering from Winona State University and MS in Engineering Management from Southern Methodist University.

DAVID CLARK, CEO of CMS wind, has experience monitoring and analyzing wind turbine from 200 kW to megawatt-class units, and from several OEMs. In addition, he as 11 years of condition monitoring experience in traditional markets such as nuclear power, steel mills, and mining.

David frequently writes for Windpower Engineering & Development.

MAC LARSEN serves as the Director of Application Development for Graco Inc. He specializes in finding technology solutions for manufacturers in composite fabrication, generally assembly, injection molding, and electronics. Larsen has more than 30 years of experience in resins and dispensing technologies and holds two patents: one for mix and dispense technology and another for controlling air nucleation.

ERIC LETHE, Vice-President of Inland Technology Incorporated, has been with the company since 1990, and was awarded certificates of appreciation for his work from USEPA, Washington Department of Ecology, NASA, the Professional Aircraft Maintenance Association, and the Association de Traitement Thermique du France. He has also presented at various environmental and industrial conferences for the aerospace, mining, and maritime industries.

JIM MAHONEY, Partner at Huron Capital Partners, is responsible for sourcing, evaluating, executing, and managing investments made by the firm. His experience includes mergers and acquisitions, equity and debt financings, and restructurings for middle-market businesses across a variety of industries. He holds a B.A. in Economics and Political Science from Villanova University and M.B.A. from The University of Chicago with concentrations in Finance and Accounting.

JATIN SHARMA, Head of Business Development, GCube Underwriting Ltd, leads the global business development team at GCube and works closely with the underwriting and claims department to develop strategic opportunities, new products, and technical reports for GCube’s insureds, lenders and insurance brokers. Jatin has 10 years’ experience in broking and underwriting renewable energy, particularly offshore wind, and holds an MSc in Climate Change Management.

SCOTT STARR, Director of Marketing for Firetrace International, has over a decade’s worth of experience in the application of special hazard fire-suppression systems. Starr received his Bachelors of Science in Business Administration from Miami University and holds a Masters of Business Administration from the Weatherhead School of Business at Case Western Reserve University. He has been working with the wind energy industry since 2005.

MICHAEL A. STOUT is an Engineering Manager with California-based Falcon Electric Inc. The company is an authority in the computer automation, power conversion, and UPS industries, with nearly two decades of experience in criticalpower systems. Stout currently specifies and designs new UPS and critical-power system products and evaluates emerging technologies.

www.windpowerengineering.com

AUGUST 2015

8/11/15 1:54 PM

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WINDPOWER ENGINEERING & DEVELOPMENT

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www.windpowerengineering.com

AUGUST 2015 • vol 7 no 4

CONTENTS

D E PA R T M E N T S 01

Editorial: I hope the nuclear guys are right.

06

Wind Watch: A home for bats, Three dynamics

In the meantime…..

shaping renewable energy, CanWEA 2015, Understanding bearing smear, Radar evaluations in site assessments, Wind work around North America

28

Security: Protecting turbines against fires in the nacelle

30

Policy: Getting to the altar with the right private equity partner

32

Reliability: Keeping wind-turbine controls working during power disruptions

18

Materials: Maximizing wind-farm ROI through blade protection and repair

34

Safety: Seven steps for making wind-power sites

22

Bolting: Torque versus clamp and what it means

36

Turbine of the Month: Goldwind 2.5 MW direct drive

26

Insurance: Cost cutting tactics can turn

60

Downwind: A nose cone for rotors boosts power output 3%

for joint integrity

chemically safer and environmentally compliant

troublesome for transformers

F E AT U R E S

38 Condition monitoring:

Shortchanged by careless vendors Condition monitoring gets accolade outside the wind industry because of its capability for lowering O&M costs. Here’s why many in the wind industry come up short.

42 Power storage with ultracapacitors

50xx ON THE COVER

GE’s Digital Twin tells where its physical twin is not working well.

When considering energy storage, chances are you aren’t thinking about the pitch-control system in a wind turbine. But these systems, standard in most utility-scale turbines, include an important power-storage component.

Emerging ideas that promise to chop costs off O&M Several recent ideas that promise to make wind farms more profitable include the possibility of wind turbines that learn, ondemand guidance for maintenance and troubleshooting, and a turbine’s perfectly performing digital twin.

46 Saving time and cost

with point-of-use resin heating Demand in the U.S. composites market is expected to grow to $10.3 billion by 2019 at a compound annual growth rate of 6.6%. Pointof-use heating is one idea that can improve productivity and keep the market growing.

4

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AUGUST 2015

8/13/15 2:13 PM

The Data Is In...

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8/13/15 3:46 PM

One way to make an artificial bat roost fixes a length of BrandenBark material to a pole, leaving a gap between the two.

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AUGUST 2015

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ARTIFICIAL ARTIFICIALBAT BATROOST ROOST SLEEPS SLEEPS 450, 450, KEEPS KEEPS THEM THEM AWAY AWAY FROM FROM RESTRICTED RESTRICTED AREAS AREAS

WHY BATS ARE ATTRACTED to working wind turbines is still something of a mystery. One theory is that they perceive the turning rotors as swaying trees. Their vision is OK but their echolocation has a maximum range of only 20 to 40 ft at best, sometimes causing them to collide with the rotor they don’t see.

Perhaps the best way to protect bat colonies from potential impacts caused by turbines is to encourage roosting to locations far off site. Copperhead Consulting is one company that has had some success in keeping colonies away from fussy neighbors, and although the example here is not a wind farm, the experience may be instructive.

“About nine years ago we did some work for a client that found a colony of Indiana bats in an area they needed to develop, and ideally, wanted the colony to relocate across a particular river,” says Copperhead Director of Energy Services Josh Adams. With the blessing of the U.S. Fish and Wildlife Service, the client set aside a plot of land for the colony and designated it an Indiana Bat Management Area (IBMA). “We began improving its habitat using various methods. We hung

Once we were able to document successful use, we immediately began researching how to improve the roosts. artificial bark on snags – dead standing trees – along with what’s called ecoshake shingles. These are small shelters with cues that would likely key on the bat’s visual preference and temperature requirements – all to get the bats to stay in the IBMA. With some success, they started moving into the artificial bark and eco-shake shingles. Once we were able to document successful use, we immediately began researching how to improve the roosts.”

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W I N D W A T C H A completed BrandenBark bat structure likely provides the visual cues that attract bats. Copperhead Consulting’s Adams says the structures require little to no maintenance, are easy to monitor, cost effective, and have been accepted by the U.S. Fish and Wildlife Service as a mitigation tool.

He adds that his consultancy has conducted presence-absence surveys on wind facilities in Illinois, Indiana, Mossuri, Tennessee, and is currently working on developments in Virginia. “Every site presents its own unique challenges and being able to come up Coordinate with the agencies early with creative solutions to complex problems allows and with help of knowledgeable developers more flexibility in forward with project consultants. Being transparent and moving plans,” he says.

His message to the wind upfront about how you are going industry is to, “Coordinate to approach any issues that may with the agencies early and arise will eliminate delays and cost with help of knowledgeable consultants. Being increases later on in the process. transparent and upfront about how you are going to approach any issues that may arise will trees on the landscape. They prefer eliminate delays and cost increases later to roost in groups but the individuals on in the process,” he says. W generally switch roosts every two-three days. The artificial structures seem to appeal to several bat species with the right temperature and visual cues.

Currently six species of bats have been documented using the roosts.

“Eastern tri-color bats, little brown bats, evening bats, big brown bats, and northern long-eared bats–now federally threatened–have all been found roosting in our structures,” says Adams. bats using the area, because we have recaptured the same ones year after year, four and five times,” he says.

Adams adds that Indiana bats roost in large colonies, maternity colonies that can number in hundreds and use multiple

WHAT DO YOU THINK?

Shortly thereafter, a good looking fake tree at a mall caught the eye of one of the naturalists. It was interesting but too big.

Could the manufacturer make something smaller, easier to handle? “We worked with the company to tweak the product to meet our needs, such as textures on the backside, and smaller dimensions to ease its handling. After installing the improved design, bats moved in by the hundreds.

At last count, 451 bats were roosting in just one shelter on the IBMA,” said Adams. These bat shelters, now called BrandenBark roosts, have been erected in seven states. What’s more, the original colony has stayed in the IBMA, away from the development, for six years.

But like recalcitrant teenagers, the occasional few will go where they should not. “We still have one or two that will occasionally roost on the wrong side of the river. We know we have the same 8

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The tiny radio transmitter allows tracking the flight pattern and location of diurnal roosts of bats.

Connect and discuss this and other wind issues with thousands of professionals online

www.windpowerengineering.com

AUGUST 2015

8/12/15 2:05 PM

W I N D W A T C H

Three dynamics are shaping the growth of renewable energy THREE SIGNIFICANT DYNAMICS ARE CHANGING the renewable-energy market and the integration of that power into the existing grids, said DNV GL Wholesale Advisory Service, Head of Section Olof Bystrom. He elaborated on the dynamics at the recent AWEA Windpower 2015 Conference along with a survey conducted by his firm. The dynamics, actually developing trends and ideas, were distilled from a global survey of about 1,600 participants in 71 countries affiliated with the power industry. “We see these changes or dynamics in the power industry as it works to integrate and accommodate more renewable energy,” said Bystrom.

One survey question revealed a surprising consensus: Is it realistic to expect 70% or more renewable energy before 2050? “Surprisingly, 80% of the respondents said ‘yes.’ That was quite an unexpected and positive response,” he said. That led to identifying the different dynamics that would produce such a shift.

The first dynamic, Beyond old metrics, looks at how the industry moves beyond the current regulatory framework to one that creates a convergence that works for developers and grid-system operators.

The cost of energy is an example of where a new metric is needed. The most common metric of affordability – the levelized cost of electricity – is often used by state regulatory commissions. It counts only the total cost relative to the total energy delivered but not when the energy is delivered or how predictable the energy delivery is. If time of delivery and firmness of delivery were part of WINDPOWER ENGINEERING & DEVELOPMENT

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Four fifths of respondents to the DNV GL survey believe that 70% renewables can be achieved by 2050.

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W I N D W A T C H the metrics, we could expect to see new ideas developing on how wind and solar can support reliability.

The second dynamic, Beyond old rules, recognizes the need to look at new paradigms for collaborating between regulators, systems operators, and developers. “This would be to develop systems or rules and regulations that can accommodate 70% renewable energy.

Even though renewables at that level are widely viewed as feasible, system operators see that level mostly as a challenge.”

The challenge lies in ensuring that the lights stay on despite a higher reliance on variable energy sources. This can also lead to higher costs because power systems must maintain more reserves to support the grid when renewable generation levels fluctuate.

Renewable energy today is often sold as-available at the spot price and systems operators simply have to accept schedules and plan around them despite the uncertain output from renewable sources. New rules or financial premiums for firmer energysupply schedules that makes delivery of renewable energy to the grid more

predictable could contribute to easing the challenge for systems operations.

The third dynamic, Beyond old silos, deals with expansion. It calls for new entrepreneurial models to expand the electric business into what DNV GL calls the Internet of Energy. “As we move to new technologies such as distributed

We need better software and communications protocols for controlling and aggregating these assets so they become part of the energy supply in a manner similar to conventional generation. generation, energy storage, and increasing market participation from demand response provided by small smart devices, such as thermostats and HVAC controls, we need better software and communications protocols for controlling and aggregating these assets so they become part of the energy supply in a manner similar to conventional generation,” says Bystrom.

The concept of a distribution system’s operator is one emerging example of how the grid is changing in

Two thirds in the DNV GL survey put storage in the top three most important technologies.

Smart grids come in second.

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that distribution utilities will increasingly find themselves becoming mini-ISOs tasked with accommodating generation from distributed solar and other smaller scale resources.

And lest you think the transitions described are decades in the future, Bystrom says they are already

happening. “Texas is definitely one of the key players in renewable energy and has built a reliable transmission system to support the development.

The combination of renewable energy there, in its tremendous wind and solar resources, is so great that ERCOT, the Electric Reliability Council of Texas, has developed Competitive Renewable Energy Zones that have vastly improved the ability to get renewable energy from wind-rich areas to where it is needed,” he says.

The western U.S. will be the next frontier with California as a bellwether state. “California Governor Brown has stated goals of 50% renewables in the mix by 2030. Should that goal lead to legislative requirements, they will probably be forthcoming. We see the dynamics in other markets too, such as the Midwest,” he says. Good resources are available throughout the area from Oklahoma to Kansas and up the middle of the country as well.

Bystrom also suggested that the three dynamics will play out differently in different regions, shaped by local electricity systems, renewable resources, business models, and political cultures.

In short, the industry must move beyond the quaint idea of simple accommodation to a new model that combines more predictable production with efficient distribution and more sophisticated operations. W

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AUGUST 2015

8/14/15 10:15 AM

W I N D W A T C H

TV or no TV? That is the recent question for site assessors AFTER A SITE ASSESSMENT COLLECTS SUFFICIENT AND BANKABLE WIND DATA, a project closes on financing and allays wildlife concerns. Other than the upcoming site construction, there seems little else to worry about. But as wind farms become more numerous, one concern not often discussed in the industry is the potential for wind-farm interference with TVs, radios, and emergency broadcast transmissions.

Broadcast Wind’s Frank Marlowe says an accurate pre-construction characterization of potential interference to television and radio transmissions is vital to the success of a windenergy project. TV and radio broadcasting signals are especially critical because they can directly impact local populations.

Marlowe has a solution to the problem of estimating changes to important transmission signals by predicting the effects of proposed wind farms on them.

“We recommend a pre-construction analysis for several types of broadcast

The yellow lines define an areas of potential interference to television signals. It is also one output of Marlowe’s software. The cells in the (inset) Area of potential Interference are where the simulated signal strength dropped from a pre-construction value above 60 dBμV (decibels above 1 microvolt/meter) to below 45 dBμV post construction.

transmissions to avoid accidentally placing turbines in obstructing locations. Wind-farm developers and other interested stakeholders, such as permitting agencies and investors, find the evaluations useful,” he says.

Marlowe uses a computer-based simulation to assess the potential for signal impairment. Simulations of signal strength from TV stations that cover the area include the proposed wind farm and regions around the proposed site.

“Electromagnetic-wave-propagation software simulates signal strength over a 3D terrain model. Individual wind turbines are modeled as features in the terrain. This allows comparing field strengths with and without the turbines,” he says.

To make signal strength measurements, the company uses proprietary, stationary remotely-monitored RF probes. These provide wind-farm developers and stakeholders with long-term TV-signal strength and signal-quality data at critical locations. The The example dashboard shows correlation between precipitation and variations to a UHF digital television signal. High wind, time of day, and seasonal changes can also play roles in signal propagation. The inset box provides measurement data for a particular time of day.

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W I N D W A T C H probes capture TV-signal metrics through changes in seasons and atmospheric conditions before, during, and after windfarm construction.

With data from the probes, Marlowe’s software can simulate transmissions and then calculate three important metrics on a dashboard as a percent scale. The metrics include: • The TV signal “SEQ” tells whether the video signal is watchable or not.

An SEQ of 99% would mean that the viewer sees a “hit” or pixilation to the video 1% of the time.

• Signal strength in dBmV (decibels above 1 microvolt/meter) and signal quality (MER) in dB are also calculated.

• “Margin” describes how much signal strength buffer there is in dB above the threshold of operation. More margin means a stronger, more stable video signal. A fourth metric, margin or signal strength buffer, is displayed in decibels (dB).

In addition to TV signals, Marlowe suggests examining potential interference with AM and FM radio stations, point-topoint and point-to-multipoint microwave systems, land mobile and emergency services, commercial Doppler and government radar, and others. A more in-depth discussion on this topic is here: http://tinyurl.com/wpe-radar. W

Electromagnetic-wavepropagation software simulates signal strength over a 3D terrain model. Individual wind turbines are modeled as features in the terrain.

This allows comparing field strengths with and without the turbines.

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Condition Monitoring More Profit, Greater Production

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10.11.2014 8/13/1508:32:29 3:48 PM

This year’s CanWEA Annual Conference and Exhibition at the Metro Toronto Convention Centre is expected to attract over 1,600 attendees.

W I N D W A T C H

OCTOBER 5 TO 7

METRO TORONTO CONVENTION CENTRE

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Last year’s CanWEA Annual Conference and Exhibition was held in Montreal, Quebec. The exhibit hall hours for this year’s event in Toronto, Ontario are: Tuesday, October 6 from 9:00am to 6:00pm and Wednesday, October 7 from 9:00am to 5:00pm.

CanWEA readies its 2015 Annual Conference and Exhibition WIND POWER IS ONE OF THE FASTEST-GROWING SOURCES OF ENERGY AROUND THE WORLD, and Canada offers no exception. Over the last five years, more wind energy capacity has been installed in Canada than any other form of electricity generation.

“Canadian wind energy enjoyed record-breaking years in 2013 and 2014, and we are on track to maintain this momentum in 2015 and 2016,” said Robert Hornung, President of CanWEA, the Canadian Wind Energy Association. “With enough wind energy to power three million average Canadian homes, Canada is one of the world’s top wind-energy producers.”

The country recently surpassed the 10-GW mark of installed wind-power capacity, making it an exciting time for the industry to come together for the 31st CanWEA Annual Conference and Exhibition this October. This year’s event will include educational sessions and keynote presentations from the Ontario Energy Minister, the Honorable Bob Chiarelli, and the Ontario Minister of the Environment and Climate Change, the Honorable Glen Murray.

Conference sessions will examine wind-energy challenges and solutions, and offer a platform for questions and discussion.

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The Status of Wind Energy in Canada’s Major Markets. CanWEA’s regional directors will provide a regional update on the wind markets in British Columbia, Alberta, Saskatchewan, Ontario, and Quebec.

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Operations and Maintenance: An Asset Manager’s Perspective.

As the country’s wind fleet grows and matures so do the O&M issues at Canadian wind farms. During this session, asset managers will discuss maintenance challenges and how to best address and overcome them.

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Cost of Wind: The Lowest Cost power Around…but for how long? An interactive panel will explore and discuss four key factors that are expected to affect the cost-competitiveness of wind relative to other sources of generation, including pure energy cost, technology evolution, value to the grid, and financing.

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Renewable Energy’s Role in Combating Climate Change in Canada. This session will include an international discussion on the role Canada should play during the Paris climate-change talks later this year, and will also cover the province of Ontario’s next steps in de-carbonizing Canada’s energy supply

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AWARDING WIND LEADERS THE ANNUAL CANWEA AWARDS BANQUET recognizes individuals and groups who have contributed significantly to the advancement of wind energy in Canada.

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Matt Holder Community Connection Award for responsible and sustainable development within a community, Friend of Wind Award for outstanding community level contributions by individuals or groups not employed by the wind-energy industry, R.J. Templin Award to an

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individual or organization that has undertaken scientific, technical, engineering, or policy research and development work that has significantly advanced the windpower industry in Canada, and Wind-energy Project Award to a CanWEA Member for a Canadian wind-power project that has demonstrated an exceptional commitment to responsible and sustainable development in all phases of a project.

Women in Renewable Energy (WiRE) will also present the Wind-power Woman of Distinction Award.

W I N D W A T C H

Along with informative panel presentations, CanWEA’s annual Innovation Zone will showcase new research and products from community and industry leaders, divided into four strategic areas: Research & Science, Electric Vehicles, Innovative Technologies (featuring battery storage, smart-grid technology, hybrid systems and more), and the Learning Centre for exhibitor presentations.

“Expect an informative, educational event,” said Hornung. “Premier exhibiting companies will also present cutting-edge technologies and innovations that will help solve the industry’s biggest problems and pave the way for a more efficient, effective, and sustainable energy future.” W

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Manufacturer duplicates bearing race smearing in lab and identifies a resistant coating WIND TURBINE GEARBOXES ARE A LITTLE MORE RELIABLE since researchers at The Timken Company have been able to reproduce smearing damage on bearings in the lab.

Producing it means they know what causes it, and later tests on selected surface treatments show that one works well eliminating the damage.

“Smearing is a damage mechanism in rolling-element bearings caused by roller skidding,” says Timken’s researcher Ryan Evans. “It’s characterized by a skid-mark type of appearance around a raceway’s circumference, with mild plastic deformation of the material surface, and the potential for adhesive wear and material transfer.”

Damage bands from smearing may change the original engineered surface texture and profiles of the bearing

Smearing is characterized by the appearance of skid marks around a raceway circumference, with mild plastic deformation of the material surface, and the potential for adhesive wear and material transfer.

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raceways, potentially leading to more advanced adhesive wear. It also serves as initiation locations for spalling damage.

So which bearings are most susceptible to smearing? “Rolling When a shaft loads a bearing in normal element bearings with inherently higher conditions, the rolling elements enter and leave roller-raceway slip are most susceptible the load zone with shaft rotation, effectively to smearing damage. More specifically, transmitting load mostly through that portion of spherical roller bearings and cylindrical the raceway about the 6 o’clock position. If the roller bearings are more at risk than shaft loading dynamics change, say from from down to up, the load zone location also changes tapered roller bearings,” says Evans. and creates an erratic load zone condition that Wind turbine gearboxes use many can significantly increase smearing risk. cylindrical roller bearings. Their damage risk is magnified when bearings operate zone to the 12 o’clock position,” says Ryan. at high speeds and low loads, as in small Generally, any transient change in the load or erratic load zones – those with rapidly zone width or angular location compared changing conditions. to steady conditions can be regarded as an Rolling element bearing performance “erratic load zone”. is most predictable when things are As with most component wear or working well, in steady state for instance. damage, the best way to solve a smearing “But consider two bearings supporting problem is to eliminate the root cause, a rotating heavy shaft influenced only by which is severe roller slip. Evans’s team gravity. In this case, the bearing load zone will be in the 6 o’clock direction and the evaluated several surface treatments and found that for the severe conditions group of rollers carrying the shaft load will studied, a roller coating identified as WC/ span an angular range around 6 o’clock. a-C:H, offered the best protection against The rollers in the 12 o’clock position are effectively unloaded against the raceways. smearing damage. “The material contains So with shaft rotation, rollers are loaded both ceramic and polymer constituents and unloaded as they pass into and out situated on a nanometer-length scale, of the load zone. If this steady situation More specifically, spherical roller bearings is disturbed in and cylindrical roller bearings are more at some way that tips or dynamically risk than tapered roller bearings. impulses the heavy shaft in an unsteady way, such as by a in other words, an engineered nanovibration or torque event (from a gust) that composite,” says Evans. He also suggests passes through the shaft, it can momentarily that follow-up studies might evaluate unload the originally steady 6 o’clock load other factors that can influence smearing zone in the bearing, either changing the risk, such as steel type, heat treatments, angular span of the load zone around the 6 lubricant-additive formulations, and o’clock location, or even moving the load various other load and speed conditions. W

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Wind work around North America The first half of 2015 saw wind power continue to grow in the U.S., in part thanks to southeastern states such as Florida and North Carolina which now purchase wind power. This is a growing trend for the region. More good news for wind industry came when the U.S. Senate Finance Committee voted 23 to 3 to extend federal tax incentives for growing renewable energy. The FERC said the U.S. added 1,969 MW of new wind capacity, a 122.7% increase over H1 2014, bringing the total U.S. wind capacity to 67,820 MW. Here are a few projects worth noting:

W I N D W A T C H

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Invenergy released plans for a 200-MW wind farm in eastern Freeborn County. The project will be built on 29,000 acres of private land with approximately 100 wind turbines. GE’s 2 MW-116 turbines are the preferred model, however selections have yet to be finalized.

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Facebook data center 100% renewable-powered Clay County, Texas Partnered with Citigroup Energy, Alterra Power, and Starwood Energy Group, Facebook is installing 200 MW of new wind energy to the Texas grid. The project will power the company’s new Fort Worth data center with 100% renewable energy. The farm is under construction on 17,000 acres about 90 miles away from Fort Worth.

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Financing complete for British Columbia’s largest wind farm Peace Region, British Columbia Pattern Energy Group has completed its financing for the 180-MW Meikle Wind project near Tumbler Ridge in British Columbia, Canada. The farm will be supplied with 35 of GE’s 3.2-103 turbines and 26 of its 2.75-120 units. Construction is expected to be completed in late 2016, along with the beginning of commercial operation. Meikle Wind will increase the installed wind power capacity of British Columbia by 38%.

Amazon Web Services hired Iberdola to build and run North Carolina’s first utility-scale wind farm, a project larger than any other in the Southeast, where nine states currently have no wind farms. The 208-MW Amazon Wind Farm U.S. East will use Gamesa wind turbines to supply electricity for Amazon’s data centers. The project will open in December 2016.

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U.S. offshore wind finally surfaces Block Island, Rhode Island The Deepwater Wind project, in a historic moment for the U.S. offshore wind industry, almost shouted “steel in the water,” laying the first foundation for the five-turbine wind farm off the coast of Block Island. The 30-MW project will consist of 6 MW Alstom turbines that will generate 125,000 MWh annually.

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North Carolina’s first wind farm Perquimans and Pasquotank Counties, North Carolina

Oklahoma welcomes Drift Sands Grady County, Oklahoma Drift Sands, a 108-MW wind power project, is being developed by TradeWind Energy and is set to start construction in the coming months. The project area encompasses 10,000 acres of private land under lease from 25 landowners. It is expected to be in service by the end of 2016.

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Strong wind resource in Minnesota Freeborn County, Minnesota

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Vermont family seeks approval for Swanton Wind Swanton, Vermont The Belisle family is seeking permission from the state government to build a wind power project on a ridge they own in Swanton, Vermont. Swanton Wind may have up to seven turbines at 20 MW, capable of producing enough electricity to power 7,800 homes. The family hopes to start construction before the end of 2016.

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EGP invests $220 million in Mexican wind Mazapil and Villa de Cos, Zacatecas Enel Green Power has planned to increase its installed capacity in Mexico to 400 MW by spending $220 million on the construction of the Vientos del Altiplano wind farm.

The project will consists of 50 wind turbines of 2 MW each, totaling 100 MW with the ability to generate 280 GWh annually. Construction completion is expected in H2 2016.

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Con Edison builds wind portfolio Pollock, South Dakota Campbell County Wind Farm Holdings completed an agreement with Consolidated Edison Development to acquire, construct, and operate a wind project on property owned by local farmers in Pollock. Currently under construction, the 95-MW wind farm is made up of 55, 1.7MW GE turbines and will soon power approximately 25,000 homes for a year.

10 Plans continue to develop for Ontario wind farm Lorrain Valley, Ontario

WPD Canada has teamed up with Timiskaming First Nation to develop the 120-MW Silver Centre project in northern Ontario. The developers aim to submit their bid to Ontario’s renewable procurement program, which includes a 300 MW allowance for wind power. Preliminary site investigations started in 2011 and if the companies’ bid is accepted, construction is anticipated to start in 2018 or 2019.

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M AT E R I AL S

Santhosh Chandrabalan Development Leader 3 M Te c h n i c a l B u s i n e s s w w w. 3 m . c o m / w i n d

Maximizing wind-farm ROI through blade protection and repair

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o maximize wind-farm efficiency and related investment returns, the wind industry is paying increasing attention to the wear and tear of turbine blades. From high winds and rain to damaging hail and salt spray, turbine blades face a wide variety of weather and environmental challenges. Exposure to these conditions over time commonly leads to erosion in the form of pitting, gouging, and delamination on the leading edge of blades.

Dry layup adhesive

This damage compromises the integrity of a blade and impacts its aerodynamic efficiency, causing a significant loss in annual energy production (AEP). Recent studies from several sources consistently demonstrate that even minor erosion can lead to an AEP loss of at least 4%, and up to 20% or more in the case of severe erosion.

The best approach to blade erosion is a proactive one, addressing the issue before it becomes one. Several materials can help prevent blade damage before it’s a problem that affects a turbine’s production and ROI. Protecting blades Today’s utility-scale turbine blades often extend more than 40-m long and are made of lightweight materials, such as fiberglass, epoxy, polyester, and core materials, depending on the manufacturer. The longest blades can achieve tip speeds of more than 200 miles-perhour, so even the smallest bits of sand or moisture can cause damage over time, regardless of the brand, material, location, or hub height.

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MATERIALS

When evaluating bladeprotection tapes, consider a product that’s UV stable without hazardous pollutants.

One of the most common products for leading-edge erosion is blade-protection tape. Originally developed for helicopter blades and aircraft radomes, tapes are constructed with durable, abrasion-resistant polyurethane elastomers. The material is tough enough to shield a blade’s leading edges and surfaces from pitting, wear, water ingression, and environmental erosion, while protecting against punctures and tears.

When evaluating blade-protection tapes, consider a product that’s UV stable without hazardous pollutants. Also check whether special tools are needed for application. Several tapes on the market are designed for use in the factory or in the field by rope or platform access. Protection tape is often one of the best choices for repairs in the field because it provides a simple and consistent solution with a uniform thickness and finish.

Unlike a chemical coating, blade tape isn’t affected by weather conditions, such as humidity or temperature, and provides a more reliable application process for quick fixes and corrections.

Blade-Protection Options

Description

Acrylic foam tapes

When attaching upgrades to a blade, an acrylic foam tape is often an ideal alternative to liquid adhesives and mechanical fasteners because the tape can withstand dynamic residual forces even in harsh conditions. These tapes are easy to apply and are extremely flexible, which accommodates the flexing and fatigue forces often encountered by a turbine blade. Acrylic foam tapes can also stand up to various temperatures and weather conditions.

Blade bonding adhesives

This bonding adhesive is a fast-curing, crack-resistant structural epoxy for bonding composite blades. Adhesives reduce turbine downtime by enhancing blade durability.

Structural adhesives

A room-temperature curing adhesive used for bonding composite turbine blades and for other general-purpose applications.

Dry layup adhesives

This sprayable, synthetic elastomer-based adhesive is used for helping to hold glass fabrics and other reinforcements and materials (i.e. flow media) in place during the infusion process.

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MATERIALS

A variety of fillers are available so before deciding on a product users should factor in the application method required, the repair time available, and the performance expectations in the field.

Polyurethane coatings provide another option for blade protection, offering a layer of defense against damage caused by sand, rain erosion, and minor impacts. But careful and proper application by brush or casting is necessary for full protection, so coatings are best applied in controlled conditions, not in the field.

Blade manufacturers also often use epoxy or polyurethane fillers to fix surface defects after de-molding or to create a smooth transition between blade halves. In these cases, the filler becomes an integral part of the leading edge of a blade. Because blades are designed to flex significantly during operations, fillers must allow for some bend while providing enough durability to prevent surface cracking.

A variety of fillers are available so before deciding on a product users should factor in the application method required, the repair time available, and the performance expectations in the field. Also, review the instructions to ensure proper mixing and adhesion to the substrate of

SURFACE PREPARATION Preparation is key to successful blade protection. Before selecting a bladeprotection product, double-check the degree of damage or repair on the blade. Serious chips or damage to the leading edge of a blade can mean a filler is needed prior to coating. After choosing the appropriate product, read the application directions and follow the recommendations including whether maintenance or repairs are best completed in the factory or in the field. Most often, the surface intended for the protection tape or coating significantly influences an adhesive’s reliability and performance. A clean and dry surface is usually required to obtain high-strength structural bonds.

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MATERIALS

a blade to decrease the possibility of application errors and waste.

Fillers technically become the base of the leading edge of a blade, so they significantly influence how that leading edge resists erosion. Coatings and blade-protection tape are also used to effectively prevent erosion, so it is important to choose a reliable filler that works in combination with other protection products.

Upgrading designs An ageing fleet occasionally leads turbine operators to implement design upgrades to improve the aerodynamic efficiency of turbine blades. In these

cases, it’s imperative to use a tough, reliable bonding solution when adhering composite blades Fillers technically become the base of or securing aerodynamic the leading edge of a blade, so they attachments.

Depending significantly influence how that leading on the project, edge resists erosion. several bonding products are available for turbine blades and proper application will increase reliability. With the right combination of leading-edge protection, operators can boost wind-farm performance, power generation, and ROI. W

BGB Technology Inc. is a leading supplier in the development of slipring solutions for the wind turbine industry. BGB is at the forefront of turbine technology and works closely with major global wind turbine manufacturers.

BGB Technology Inc. has expertise in: •

Hub control sliprings for both electrical and hydraulic pitch shift systems (main shaft)

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Power supply systems (main shaft)

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Generator / frequency converter sliprings and brush holders (generator high speed shaft)

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Lightning defense brushes & static earth dissipation systems (main bearings and slewing rings)

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Cable looms & harnesses for turbines

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Brush holders

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Fiber Optic Rotary Joints - FORJ (a fiber optic solution which is not influenced by vibration, humidity, heat, magnetism)

BGB Technology, Inc. 1060 Port Walthall Drive Colonial Heights, Virginia 23834 Tel: 804.451.5211 Fax: 804.451.5615 Mail: mail@bgbtechnology.com Web: www.bgbtechnology.com

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B O LT I NG Ryan Bonner Alcoa Fastening Systems & Rings

Torque versus clamp and what it means for joint integrity and vibration resistance

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or most heavy equipment applications, design engineers have focused on a stable, consistently tight joint for long-term durability and vibration resistance. At the same time, torque has long been the standard by which the tightness, and maybe even the overall integrity, of a joint were measured. This conventional thinking was based on the idea that the more power applied to a nut and bolt assembly in the form of torque, the tighter, more secure, and vibration resistant the joint. Unfortunately, the belief that higher torque resulted in a more secure and durable joint is incorrect.

Torque explained Torque, as it relates to fasteners, is the twisting force required to spin a nut along the thread of a bolt. The basic equation for torque is T= (KDP)/12

where T = torque, ft.-lb; D = nominal diameter, in.; P = required clamp load or tension, lb; and K =

coefficient of friction. The problem with this equation is that K is difficult to predict or measure because it is impacted by a wide range of variables such as surface texture, oil, rust, debris, type of thread, material, and even humidity.

Tension, P in the equation, stretches or elongates a bolt so it provides the clamp on the joint. Tension is also the load on the joint brought about by drawing the fastener components together. Critical to a joint, tension, is for the most part unrelated to torque. At best, torque is an indirect measurement of the tension applied to the bolt.

Eliminating vibration’s effect The last line in the table below suggests there is a better fastener. Several design elements of HuckBolts – a swaged lockbolt – ensure their resistance to the effects of vibration. In conventional nut and bolt installations, gaps between the nut and bolt threads are universally encountered, providing the opportunity for loosening in high-vibration environments. By contrast, the Huck design, featuring a collar fully swaged into the locking grooves of the pin, creates no such problematic gap.

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The HuckBolt is installed by the installation tool stretching the pin and then providing a swaging action that deforms the collar (tan component) material into the locking grooves on the pin.

The result is vibration-resistant and permanent.

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B O LT I N G

Instead of the deep threads necessary for a tolerance fit between conventional nuts and bolts, the HuckBolt pin requires only shallow locking grooves into which the collar is swaged. The design of the locking grooves allows for a much larger root radius, which contributes significantly to the fatigue strength – up to five times that of a conventional nut and bolt. Overall, this lockbolt design provides superior vibration resistance as indicated by the study in the table.

Vibration resistance Because this fastening technology can withstand the effects of vibration without ever loosening, the fastener never needs inspecting, tightening, or re-torquing. The benefits that accrue from this ability to withstand the effects of vibration include:

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Eliminating a costly aspect of tower maintenance because there is no need to expend manpower and time to periodically inspect, tighten, and torque existing fasteners.

A tower assembled with HuckBolts may never be off line for inspection and remediation of fasteners.

Finally, vibration-resistant lockbolts almost eliminate the safety problems from a failed fastener.

What’s more, DIBt Institute has certified the 12, 14, 16 , and 20 mm, and 1 inch dia. bolts maintenance-free. A BobTail Butzkies GmbH constructed a special lattice wind tower with a hub height of 61.5 m, fitted with a total of 4,360 lockbolts. Alexander Petri (left) AFSR Sales Manager, Germany and Detlef Bengs, Managing Director of Butzkies Stahlbau GmbH, pose with their towering achievement.

AN OUTSTANDING DESIGN

DESERVES OUTSTANDING CONNECTIONS

HYTORC Washer™

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B O LT I N G

Four installation steps for the BobTail HuckBolt

HuckBolt can be installed in as little as two seconds, based on a typical installation of a 5/8-in. Grade 8 fastener.

The Huckbolt at work The BobTail line of fasteners, certified as “maintenance-free,” was selected by steel construction company Butzkies GmbH for a special lattice wind tower. Based on the positive results achieved using the bolts a pilot project, the company decided to use BobTails for fabrication of its innovative wind lattice towers. In an initial phase, three towers (each at hub height of 100m) will be built using the BobTail system.

In wind turbine towers, mechanical anchoring and fastening elements are exposed to extremely high vibration. The tension

Nut-and-bolt clamp scatter (at time 0) is much wider than that of the BobTail design. Once vibration begins, clamp load quickly decays with conventional nuts and bolts, while it holds constant with the BobTail.

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Step 1. The pin is inserted into a prepared hole, and the collar is spun onto the pin. 2. The installation tool is applied to annular pull grooves.

Activating the tool lets a puller in the nose assembly draw the pin into the tool, causing the swaging anvil to press on the collar, drawing up any sheet gap. 3. At a predetermined force, the anvil begins to swage the collar into the pin’s lock grooves. Continued swaging elongates the collar and pin, developing precise clamp. 4. After swaging of the collar into the pin’s lock grooves, the tool ejects the fastener and releases the puller.

on the wind lattice tower increases significantly with hub height.

Detlef Bengs, managing director of Butzkies Stahlbau explains this phenomena in terms of fastener performance: “No conventional threaded fastener is permanently resistant to extreme mechanical tension or vibration. Threaded fasteners loosen over time, which can result in considerable problems with a lattice wind tower.

To comply with regulations for operational stability, threaded fasteners must be repeatedly checked, re-tightened and, if required, replaced. This issue can cost the operator large sums of money over the years. From the start, we wanted to avoid this problem with our tower. For this reason, we decided not to use conventional threaded fasteners, and alternatively to build our test plant using Huck BobTail fasteners.”

A “tower monitoring” pilot test was set up as a collaborative research project with the Rostock Applications Centre for Large Structures in Production Engineering of the FraunhoferGesellschaft and the Business Development and Technology Transfer Corporation of Schleswig-Holstein.

The initial advantages of the BobTail system emerged during construction. The tower was erected on site in record time, mostly because BobTail fasteners can be installed about 75% faster than comparable conventional threaded fasteners. This speed of installation for the prototype saved about 14 hours.

In addition to Installation speed, the decisive added value was eliminating time-consuming and high-cost maintenance work, a factor that could cost almost €15,000 for a lattice wind tower at 130-m hub height. This potential cost is eliminated by the maintenance-free performance of BobTail fasteners.

The Deutsches Institut für Bautechnik, DIBt also confirmed this special attribute by issuing the “National technical approval” (Number Z-14.4-591). By contrast, regular maintenance work is mandatory when conventional threaded fasteners are used in the fabrication of towers. W

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I AM AUTOMATING CMS FOR YOU

Junda Zhu, PhD RNRG Engineer Vermont USA Advanced diagnostics or accessible information?

With TurbinePhD you don’t have to choose. Learn how input from customers guided Junda and our development team to deliver the easiest-to-use condition monitoring system in the wind industry. www.renewablenrgsystems.com/TurbinePhD

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INSU R ANCE Jatin Sharma Head of Business Development GCube Underwriting Ltd.

Cost-cutting tactics can turn troublesome for transformers A fire in a substation has disabled a step-up transformer. According to GCube, transformer losses can run between $5 million to $25 million and replacements can take up to 18 months. Yet, many project developers targeting immediate cost savings continue to design and build singletransformer sites with little system redundancy.

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n April 2013, a group of unknown gunmen targeted a Pacific Gas & Electric Co. substation near San Jose, California. The assault knocked out 17 high-voltage transformers and raised national concerns about the security of the U.S. electricity grid. Thankfully, the attack was unique in terms of its scale and organization.

However, in targeting a substation, these unidentified assailants indirectly highlighted the inherent vulnerability of the transformer as an asset. They also revealed the potential for it to become a major bottleneck and cause substantial financial loss should any downtime occur. With the U.S. wind-energy industry migrating into high-risk emerging markets overseas and driving to cut production and operating costs at home, it’s important to keep on top of potential issues, such as a down transformer.

With this in mind, GCube recently authored a report on transformer failure for insureds and brokers. Transformers: Age of Breakdown? uses claims data and market experience to analyze the causes and financial impact of transformer incidents in the renewable-energy sector. The report raises concerns about the risk mitigation and contingency measures employed by project developers and operators in the current market.

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INSURANCE

The generator step-up transformer is a critical component project downtime in the event of transformer failure. required for distribution of electricity to the grid. The task is In particular, owners of larger projects must start essential for revenue generation, making it one of the most evaluating the long-term cost benefits of their risk mitigation valuable parts of a wind farm. and contingency measures. Whether it’s by building A conventional transformer for an onshore wind farm costs greater system redundancy into electrical infrastructures or from $3 million to $10 million to manufacture and install. The formulating robust repair and replacement strategies. entire transformer market is estimated to be worth $20 billion to Project stakeholders should adjust their focus $22 billion in asset values. The true value of a single transformer to away from immediate cost-cutting tactics and toward an asset owner, however, cannot be understated, With the U.S. wind-energy industry migrating into high-risk emerging considering any markets overseas and driving to cut production and operating costs at home, downtime will prevent power it’s important to keep on top of potential issues, such as a down transformer. export and directly impact project revenues, including possible offtake penalties. Claims vary sustainability and longevity. It will only take a few multidepending on the associated revenue lost. However, one can million dollar downtime events to demonstrate how severe expect a loss between $5 million to $25 million. an impact transformer failure can have on the balance Each year, 15 to 20 generator step-up transformer incidents sheet and encourage a more proactive approach to are reported in the global wind-energy industry. GCube estimates managing technological, logistical, and financial risk. W the number of unreported downtime events to be several times higher. The rate and severity of incidents continues to increase with the expansion of the industry.

While the frequency of transformer failures may seem low when compared to other onsite losses such as blade breakage or gearbox failure, the financial impact of these incidents has grown at a considerably faster rate. This is due, in part, to remote windRUBBER TRACK CONVERSIONS farm sites in developing markets such as Latin America and Africa, and prolonged downtime at larger project sites, such as those in with over 100 models up to 80,000lbs gvw the U.S., Canada and Australia, which have often been designed with just a single transformer. What’s more, the downtime is often prolonged by replacement lead times of 6 to 18 months. And despite a ramp-up in the supply chain, transporting transformers from manufacturing hubs in North America, Europe, and Asia to remote project locations worldwide remains a considerable logistical undertaking.

Furthermore, the potential of transformer failure to severely impair the long-term operational and financial performance of a wind farm is evident. However, many project developers targeting immediate cost savings continue to design and build single-transformer sites with little system redundancy. The associated electrical infrastructure risk is subsequently offloaded to a third party using an insurance contract, and no further action is taken. Ultimately, these short-sighted measures to reduce the levelized cost of energy come at the expense of delivering a more sustainable project that continues to perform throughout its 20year life expectancy.

This concerning trend extends beyond the insurance market.

It highlights a growing urgency for project owners and operators to adopt more effective preventative maintenance regimes and RUBBER TRACK CONVERSIONS ensure they are suitably covered in insurance terms. The trend also highlights a need to develop appropriate strategies to minimize

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S E C U R I TY Scott Starr Director of Marketing Firetrace International

Making the case for wind turbine fire detection and suppression systems

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ire provides the second highest risk of damage to wind turbines after blade failure. A fire can spark because of mechanical failure, electrical malfunction, or a lightning strike. These sparks can ignite flammable materials inside the nacelle such as resin, fiberglass, or insulation contaminated with oil deposits.

Once a turbine catches fire, there are limited suppression options because of the height of the tower and remote location of most turbines.

Unless the nacelle is already equipped with a fire-suppression system, about the only option is to let the fire burn out.

Considering a 2.5 to 3.0-MW commercialscale wind turbine is valued at $3 to $4 million, with an output averaging $2,800 per day, fire damage equates to a serious loss in ROI for owners. Larger fires can result in a complete loss of a turbine, but even minor fires and power surges can lead to weeks of downtime and lost revenue.

The problem is bigger than most people and even those in the industry realize because most turbine fires go unreported. In the last four years, 30 large wind-turbine fire incidents were covered in the mainstream media, causing property damage of between $750,000 to $6 million each, including loss of productivity.

So what options do wind-farm owners have to protect themselves against fire risks and potential investment losses? Several ideas have been tried and tested in the wind industry, such as increasing the number of maintenance checks, avoiding use of combustible materials, installing conditionmonitoring and lightning-protection systems, and completely redesigning wind turbines. The problem is that all of these measures involve a substantial investment increase.

Today, many owners and operators are taking no chances and so incorporate some type of automatic fire-detection or suppression system in their turbines. Cost varies depending on the system and manufacturer but, on average, fire suppression is less than 1% of the value of a wind turbine. Whether detecting or suppressing a fire, most systems can make a difference, but they come with their fair share of design challenges. They must tolerate dust, vibration, temperature and weather fluctuations, and they must limit the number of false alarms that occur.

Of the many types of fire detection available, some use smoke-detection or air-sampling systems.

These systems

Firetrace International offers a fully automatic fire-suppression system with minimal space requirements for specific areas within the nacelle and tower base. Tailored to the individual turbine, the system is self-contained, requires no electricity to operate, and offers 24/7 protection using the company’s signature Firetrace Detection Tubing.

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SECURITY

Traditional fire-suppression systems are impractical because of their weight and the impact of the turbine environment, which includes vibration, temperature extremes, dust, and airflow. The Firetrace firesuppression system uses linear pneumatic detection tubing (red) routed through the most likely areas of a fire. When it detects high heat or flame, the tubing releases a clean agent that suppresses the fire without affecting the health of workers or equipment.

are ideal for detecting initial flames, but fluctuating airflows and varying climate conditions can impact their effectiveness. Traditional linear heat-detection systems and fusible link-detection systems (designed to activate when temperatures increase to the point that causes the fusible link to break apart) provide an alternative and aren’t affected by air or dust.

However, they are electrically conductive and provide some risk in a turbine environment.

All of these detection devices also come with power and control requirements, which means that these systems will shutdown when the external power or battery backup fails.

Several fire-suppressing agent types have also undergone evaluation for use in wind-turbine applications. Compressed airfoam systems and water mists are examples of common suppression products. But concerns in the wind industry about their effectiveness on energized electrical components and potential corrosion hazards have limited their use in turbines.

Carbon dioxide also holds attributes that make for an effective fire-suppression system. It has a high rate of expansion and can act quickly on fires. However it comes with serious risks to personnel because it depletes oxygen when in use, so an alternative is preferable when possible. Strict regulations and lockout requirements are associated with carbon dioxide use to protect workers in the event of a discharge. The weight of most suppression systems and space required to store them can also pose a problem in the cramped environment of a turbine’s nacelle.

As separate standalone systems, fire detection and suppression only offer so much protection against a turbine fire. It’s perhaps no surprise that by combining the benefits of each device, some of the most adopted systems today offer component-level fire detection and suppression in a single package. These systems are now available to the wind industry and are designed to detect small fires inside critical cabinets, significantly improving the system response time and reliability AUGUST 2015

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Electrical fires can result from shorts in equipment and surges from lightning strikes. Secondary wind-driven brush fires can also result in additional damage.

while limiting fire damage. Thanks to new designs, most also offer a lightweight device that’s much smaller that previous systems, making them a good fit for wind turbines.

Look for a joint system that uses a “clean” agent for fire suppression, meaning it uses a non-conductive, non-corrosive gas that doesn’t require clean-up afterword. Clean agents are effective inside the cabinets of a nacelle, using only a small volume so they don’t present a hazard to nearby workers or personnel. Products that offer a targeted approach to fire safety are also usually worth the investment. The authority on fire safety, the National Fire Protection Association’s NFPA 850 ruling recommends specific areas to protect in the nacelle and tower base, including the control cabinet, hydraulic station, transformer, brake, and capacitor. Ideally, each component should undergo its own assessment to ensure fire safety.

For wind owners and operators, investing in a reliable fire-safety system can save the potentially extensive costs of unexpected turbine fires. The presence of a joint automatic fire-detection and suppression system is currently one of the more reliable choices for providing 24/7 unsupervised protection to quickly address a growing fire and limit its damage and ROI loss. W windpowerengineering.com

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P O L I CY

Jim Mahoney Partner Huron Capital Partners w w w. h u r o n c a p i t a l . c o m

Getting to the altar with the right private equity partner

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or a business owner, partnering with a private equity firm is similar to getting married. Although a clear consensus doesn’t exist about how many months or years to date someone before tying the knot, the experts offer this advice: as long as it takes for the couple to learn about one another’s character, habits (good and bad), and goals, and to ensure their future plans are in sync. This same advice applies to selecting the right private equity partner.

The due diligence period is akin to dating because it lets both parties get to know each other better. It also provides time for a private equity firm to study the financial, customer, and product data, along with other pertinent information about the company. This process is about gathering enough information to qualify that the partnership will work.

So what characteristics should a business owner consider when evaluating a potential private equity partner? Here are the top five areas to assess during the “courting” process.

and respect comes an ability to speak honestly without fear of criticism. If either party is compelled to hide something because of concerns about the other party’s reaction, it’s likely not the right partnership. When it comes to choosing a partner and the right equity firm, the more you know the better.

2. For richer and poorer. Profitability and growth are usually the primary drivers of company development. Although many strategies exist to boost productivity, including working capital optimization, capacity utilization, and operational improvements, a common approach and goals are important in a working relationship. This is why private equity firms usually create a comprehensive financial forecast for a company that models the impact of operating and sales initiatives on earnings, investment returns, and risk profiles. A transaction often moves forward with an open-book analysis showing both parties the calculations behind the projected value for present and future company development.

1. From this day forward. In the “getting to know each other” stage, it’s important the buyer and seller openly share thoughts, opinions, and data about each business for the viability of the partnership—while reserving judgment. The basis for good communication is trust and mutuality, so a high degree of mutual respect. With trust Before signing contracts with a private equity buyer, perform your due diligence to ensure the firm holds similar goals for your company.

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POLICY

This financial model can also serve as a company’s overall investment thesis and growth strategy, while giving the private equity firm a “company plan” from which to work from.

3. For better or worse. One sign that you’ve found the right partner is that you’re in agreement about finances. The same holds true when looking for a private equity partner. This is especially important if you’re planning to reinvest or “roll” a portion of the ownership from the sale of the company or planning to share in future profits. Most platform acquisitions include some level of seller or management rollover. At the same time, mutual respect and loyalty are important for good business and a lasting relationship. Know your values and what you expect in a partner. Integrity is as valuable to personality as it is to business earnings, and will show up over time through partnership discussions and interactions. Use the courtship time wisely to ensure both partners share mutual goals and values, while learning about one another’s differences and making sure they are no deal breakers.

4. To have and to hold. The group you surround yourself with says a lot about who you are. Get to know the private equity firm’s team and network, and decide if it’s the company you want to keep. Meet the operating partners, senior advisors, and former and current portfolio company CEOs. Ask to meet as many of the firm’s colleagues as possible during the due diligence process and, ideally, do so without the dealmakers in the room. A private equity’s “extended family” is also important because a firm will often rely heavily on its network to fill boardof-director and outside consultant positions. A firm that includes an industry expert or operating executive throughout the due diligence process is often a plus because he or she usually provides third-person insight from the seller’s perspective.

Finding the right private equity firm is similar to getting married. It takes research, planning, and a strong partnership.

WHAT DO YOU THINK? Connect and discuss this and other solar issues with thousands of professionals online

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5. In sickness and in health. Business, much like life, doesn’t always go as planned. Whether it’s the loss of a major customer, a product recall, or a facility fire, such unforeseen incidents can have a profound impact on the revenue and earnings of a business. Know how your partner will react, and ask the private equity firm for past examples of challenges they’ve faced and overcome. Also ask for references and try to connect with a couple of the firm’s portfolio companies to get an inside scoop.

Learning about how the private equity firm copes in good times and in bad and how they react in resolving business ups and downs is another way to ensure you’ve selected the right partner.

Bottom line: do your homework. While a potential private equity buyer is performing due diligence on your company and management team, the reverse should also hold true. What you learn during this process will likely determine what partner you take to the altar. W windpowerengineering.com

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R E L I ABI L ITY Michael A. Stout Vice President of Engineering Falcon Electric

Keeping wind-turbine controls working during power disruptions

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he aim of wind-farm operators is to ensure optimal performance and consistent power generation, and maintain the safety and reliability of each turbine. With these goals in mind, there are a myriad of electrical and electronic components to consider for safe turbine operations. Such components include blade-pitch controls, braking systems, I/O modules, relays, hub computers, frequency converters, remote terminal units (RTUs), supervisory control and data acquisition (SCADA) interfaces, distribution boards, and more.

Protecting each of these systems against power disruptions is challenging given the variable nature of wind and harsh environmental conditions most turbines face.

What’s more, a conventional uninterruptable power supply (UPS), an electrical device that could provide emergency backup power, isn’t designed to withstand extreme temperatures or sporadic weather conditions.

The operational temperature specifications for most online UPS products on the market are stated as 0° to 40°C (32° to 104°F). As part of a safety agency product evaluation, the temperature ratings of key electronic components, displays, plastics, circuit-board materials, insulating materials, and batteries are verified to stay within certain temperature specifications, while the UPS operates over the entire manufacturer-specified temperature range.

Most UPS units have also undergone safety-agency testing over the manufacturer’s stated operational temperature range and have received a Nationally Recognized Testing Laboratory or Underwriters Laboratories listing for use over the stated range. But most are also engineered for use in an indoor, temperaturecontrolled environment, which isn’t typical of a

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Wind-turbine control panels like this one help maximize turbine performance while ensuring low operational costs and maximum power output.

(Source: kk-electronics)

wind-farm environment. So it’s important to know what to expect when selecting a system.

Installing a commercial, off-the-shelf UPS as a backup power device in a wind turbine might save money in the short term, but it isn’t a secure investment for the nearinstantaneous protection from potential power interruptions that turbines are likely to encounter. Industrial-grade UPS’s are for harsh environments. These devices offer high-temperature components with an operating range of -30° to 60°C (-22° to 140°F) that better meets most wind-farm conditions.

Some industrial UPS units are even pre-packaged inside NEMA 3 and environmentally controlled NEMA 4-rated enclosures. The National Association of Electrical Equipment’s “NEMA”-rated enclosure are constructed for indoor or outdoor use and provide a high degree of protection to personnel against access to the equipment’s hazardous parts and to the internal equipment (for instance, against foreign

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RELIABILITY

An online UPS regenerates clean, regulated power

An industrial, online UPS eliminates many kinds of power anomalies, providing a much more stable power source when operating from utility and with batteries.

Because wind turbines are often subjected to variable conditions, a reliable control system is needed to ensure continuous operation.

Falcon Electric’s SSG Series of pre-configured UPS devices offer a double-conversion online sinewave design that’s UL listed for effective use in extreme temperatures.

objects such as wind-blown dirt). NEMA4 protection also safeguards equipment against water and ice.

These turnkey systems provide a fast, cost-effective solution for deploying highlevel power conditioning and backup in harsh-rated environments, such as those common to wind farms. For NEMA 3-rated systems, however, it’s important to pair the UPS with reliable batteries that support a wide operational temperature range. This is not the case for environmentally controlled NEMA 4 systems where it’s possible to incorporate 10-year, long-life batteries.

The best industrial UPS devices also feature double-conversion online technology. In an online UPS, the batteries are always connected to the inverter instead of the ac power, so power-transfer switches are unnecessary.

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When it comes to protecting critical of power conditioning and protection, wind-turbine systems located in harsh in addition to providing long-term temperature environments, consider battery backup protection.

UPS units that are built from the ground The UPS design topology is similar up to withstand wide temperature to that of a switch-mode power supply. variances and operate reliably over the The online UPS rectifies and filters the long term. While the initial purchase incoming utility or generator power price of a non-industrial UPS is less to a steady, regulated direct current expensive, the return on investment (dc). Frequency variation, high-voltage transients, voltage sags and swells, is lower because maintenance issues and harmonic distortion aren’t Protecting each of these systems against a concern and don’t affect power disruptions is challenging given power reliability. the variable nature of wind and harsh Clean, regulated dc environmental conditions most turbines is then fed to and required battery replacements far a pulse-width modulated inverter stage outweigh initial cost savings. that recreates clean, tightly regulated, true sinewave ac power. Before drawing Double-conversion online industrial UPS devices currently offer the highest power from its internal battery, the online level of power conditioning and battery UPS also has large electrolytic-storage backup protection that wind-turbine capacitors that let it ride through voltage applications require. Wind-farm operators dropouts. Unlike a switch-mode power supply, the online UPS has an advantage looking to safeguard their investment are well served to research and select with battery backup capabilities that UPS options that protect against power power critical equipment for minutes from its internal batteries to hours or days pollution and provide long-term reliability in demanding environments. W using extended battery packs. windpowerengineering.com

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SA F E TY

Eric Lethe Vice President I n l a n d Te c h n o l o g y I n c . w w w. i n l a n d t e c h . c o m

Seven steps for making windpower sites chemically safer and environmentally compliant

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he need for environmentally compliant processes and materials in the renewable energy industry has grown substantially as the market for clean power has matured.

Even though wind turbines don’t use combustion to generate electricity, and therefore don’t produce air emissions, there are still risks of toxic or hazardous materials in lubricating and hydraulic oils, and insulating fluids. Turbine components, such as blades, rotors, and compressors, also need upkeep and cleaning, and while many non-hazardous, biodegradable cleaners exist, that’s no guarantee they are used on every turbine.

Even before construction begins on a wind farm, most engineers are busy at some workshop formulating new materials or constructing new components—and chances are high that workshop contains some forms of hazardous materials related to the job or after-hours cleaning. The presence of industrial equipment during turbinerelated construction, maintenance, and transportation also yields potential risks.

In the past, price, speed, and tradition were the primary criteria by which chemicals and materials were procured. With the advent of environmental regulations, processes have changed.

However, most site or shop managers aren’t chemists or environmental engineers, and typically are only skilled in the basic policies of compliance and remediation.

Ideally, the examination of each process that uses potentially hazardous

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chemicals in a work environment should occur with each new project to determine if that process is even necessary. As part of a risk assessment, insurance companies are increasingly interested in the volume of hazardous materials on a jobsite. Despite safety regulations, the cost of worker illness or a chemical-related injury is rarely calculated into the price of a potentially hazardous cleaner or chemical oil.

As a general rule, the faster a chemical evaporates the greater the potential for a hazard associated with that chemical’s use, whether the hazard is toxicity, smog formation, flammability, or potential for ozone depletion. It is most likely that the alternative candidate material will evaporate more slowly. When selecting effective solvents or substitutes, it’s critically important to select a course of action based on each process rather than each chemical.

Methyl Ethyl Ketone (MEK), for example, is a solvent used in many applications. More than 60% of MEK evaporates without

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SAFETY

cleaning anything. With acetone that figure is closer to 80%. The actual cleaning is done with only 20% to 40% of the solvent and the remaining percentage is wasted into the air and, potentially, into the lungs of the person using it. Nonetheless, searching for an alternative is of little value without knowledge of MEK’s intended use, whether that involves surface cleaning prior to painting, cleaning prior to welding, cleaning already painted equipment, or something else.

It’s important to assume the premise that a substitute material will behave differently, and not for all of the applications of the original material. What’s called for is an organized method for

determining the applicability of candidate materials, based on a “needs assessment” of the affected processes.

Even with the best intentions, there are two common challenges when it comes to making changes at most jobsites, even if they are as simple as using a new hydraulic oil. When it relates to a new product, there’s always the risk it might fail to perform or meet expectations. This is why testing is important. The second challenge is worker compliance. Change is difficult for most people.

For a manager, it’s worth considering the question: “Was the problem that the chemical did not work, or was the problem that the personnel would not

work with the chemical?” In this case, communication is key. A site manager is likely aware of the reasons and regulations driving the process of change, but the personnel are the people who are working with the new materials and who will, ultimately, determine the success of a project. A two-way street of shared knowledge and experiences is extremely important when using potentially hazardous and costly materials.

An updated and organized method for solvent implementation and substitution is necessary for proper environmental compliance and, most importantly, for providing a safe and healthy work environment. W

SEVEN STEPS TO A SAFER WORKING ENVIRONMENT To ensure successful use of solvents and reduce the risk of injury or accidents, site and project managers should consider the following steps:

1. Identify targets. Do your research and make a list of

real or potential hazardous waste sources or health and safety material concerns at each jobsite. At a wind farm, this could even mean ensuring due diligence with the contractors on the job, verifying that equipment and transportation vehicles are up to code.

2. Describe all processes. Know what materials and solvents are used on a jobsite and know the purpose of each one.

If a gearbox developer recommends a certain lubricant, understand its constituents and possible toxicity level.

3. Share the knowledge. Ensure workers and personnel are aware of onsite chemicals, and let staff know of pertinent solvent substitution efforts.

4. Learn about new candidates. If necessary, request current vendors or contracts provide a list of environmentally responsible substitutes for the target solvents. These requests should be application specific and contain Material Safety Data Sheets (MSDS) that fully indicate the contents of the candidate material. Directly contact the manufacturer for this list if it’s not readily available.

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5. Run a test trial. Always test new materials and

substitute solvents offsite before committing to their use, and try new materials in a limited and controlled area at first. For instance, as a wind-farm developer interested in switching from conventional petroleumbased hydraulic fluids to biodegradable ones, you might not have a spare offsite turbine to test the new lubricant. But the vendor should offer proven test results and referrals. It’s also possible to try the new product on one turbine before committing to your entire fleet.

6. Train employees. Whenever new materials or

substation solvents are used, it’s imperative to develop a clearly defined method for application. Ask the vendor of the candidate material to supply training or references. During the training period, make sure there are opportunities to integrate suggestions from personnel who will actually use the product. Often this is the best way to develop the most efficient methods for use of a new material.

7. Evaluate. Establish a time frame for the primary

implementation. At the end of the period, call in representatives of each step of the usage process and obtain feedback on the new materials.

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T U R BI NE OF THE MO NTH

Joshua Smalley Assistant Editor Windpower Engineering & Development w w w. w i n d p o w e r e n g i n e e r i n g . c o m

Goldwind’s 2.5-MW direct-drive turbine

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hen many turbines have so much in common – gearboxes, general layouts, and geared pitch drives – it’s refreshing to find even a little out-of-the-box thinking.

For instance, the Chinese engineers behind the Goldwind 2.5 PMDD (permanent magnet, direct-drive) have broken with convention in several areas.

Most noticeably, there is no gearbox, a troubleprone unit in conventional designs. In its place is the permanent-magnet generator (PMG), which works efficiently with minimal losses. What’s more, the generator has only one moving part (the generator rotor) as opposed to the more than 13 gears and hundreds of other parts in a conventional gearbox. The PMG also eliminates the need for an electrical feed excitation and its resulting energy losses. A full-power converter, which allows for a reactive power feed, ensures compliance with grid-code requirements, and offers low-voltage and zero-voltage ride-through capabilities. Goldwind added that the generator has a smaller external diameter compared to wound rotor designs.

Rotor diameters of 100, 109 or 121m let the turbine maximizes production in a range of wind regimes. The 109-m, for example, is optimal for mid and low-wind speed environments (Class II and III), while the 121-m works best at low-wind speed sites (Class III).

The yaw system includes four induction drive motors and hydraulic brakes, and has a comparatively slow rotational speed. The company said this extends bearing service life in the drives, and eliminates the need for high-speed bearings, couplings and high-speed brakes. Also, an automatic lubricating system for the yaw bearing reduces the frequency of unplanned maintenance.

Goldwind said the design of the 2.5-MW PMDD removes the sources of expensive faults that require crane mobilization. The combination of the PMG and direct-drive technology result in lowest-in-class, tophead mass, putting crane requirements in the same class as some 1.5 MW offerings. Another plus: the single-main-bearing design allows for a smaller physical structure, which makes it easier to transport.

In the 2.5 MW PMDD, direct-drive technology uses a generator close coupled to the rotor for few turing parts, as opposed to the more than 13 gears and hundreds of other parts in a conventional gearbox.

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TURBINE OF THE MONTH

Additionally, the turbine’s toothless, belt-driven pitch drive eliminates the localized wear experienced by gear-driven pitch drives, which then reduces backlash, vibration, and replacement costs. Ultra-capacitors are used in place of traditional lead-acid or gel batteries in the pitch system. Ultra-capacitors charge faster and more efficiently, and work well over a wider temperature range.

The turbine also comes with microprocessor-controlled condition monitoring, including remote processing. W

Goldwind 2.5 MW, by the numbers Nominal power

2.5 MW

Rotor diameter

100, 109, or 121m

Swept area

7,823, 9,516, and

11,595 m2

Blade length

53.2 or 59.5 m

Hub heights

80, 90, 95, or 120 m

Cut-in speed

3 m/sec

Cut-out speed

25 m/sec (100, 109 m)

or 22 m/sec (121 m)

Nominal voltage

690V

Nominal frequency

50 or 60 Hz

Wind class

IIA (100 m), IIA/IIIA

(109 m) or IIIB (121 m) A look inside the nacelle shows a few more details.

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CONDITION MONITORING

There is really only one right way David Clark

PRESIDENT CMS WIND

The green shaded arrows indicate the correct location for sensors. On the main bearing, the sensor would be mounted on the lower half of the unit.

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Condition monitoring gets accolades outside the wind industry because of the value it brings to lowering O&M costs. Here’s why many in the wind industry come up short.

S

uppose you have recently realized the cost justification for condition monitoring. Influencing the decision is that other vertical markets already recognize the value of condition monitoring systems. But before you can pursue installation, you are halted by the question: how do you select a good system? Buying an ineffective condition-monitoring system (CMS) has contributed to the failure of wider acceptance of CMS in the wind industry and you certainly don’t want to make their mistakes.

To complicate the selection, its seems vendors play a game of “specmanship” in which each CMS manufacturer compares the features of their systems to others, looking for a competitive edge. The core functions of portable CMS devices however, are made to fit into a wide variety of vertical markets. Unfortunately, the same parity does not exist in wind CMS offerings.

Why is it that one can pick up a portable CMS device (which for safety reasons, cannot be used in wind turbines) and software from any of six different vendors, walk into six different plants, and have all of them work well? The converse cannot be said for the wind industry. This is an important observation and it is hurting CMS, O&M costs, and the wind industry. Shame on us as consumers, vendors, and service companies for letting it perpetuate. The shortcomings affect us all.

Part of the problem is the erroneous assumption that all condition monitoring systems for wind turbines are the same. That is like saying all cars are the same. The variances in the CM systems aimed at the wind industry creates problems and the slow acceptance of this useful technology. This is definitely not the case in the other vertical markets. Reasons for the problems in the wind industry include:

How different OEM-installed CMS stack up CMS brand

Are the sensors appropriate...

...and mounted in the correct places?

A

Yes

Yes

Still had monitoring and detection issues

B

No

No

Trended for 9 to 12 months, but had detection issues

C

No

No

No sensors were in right locations, had detection issues

D

No

No

Had detection issues

E

No

No

Claimed only 40 to 80% detection rates

F

No

No

Had monitoring, detection, and software issues

G

No

No

Had monitoring and detection issues

Problems encountered

Source: CMS Wind Why is it so difficult to install a system correctly? Such widespread problems point to other systemic issues. Inevitably, the end results were missed detections and false alarms.

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The red arrow indicates a wrong sensor and wrong location. The good news here is that the generator is properly instrumented, but the rest of drive line is fitted with the wrong sensors in the wrong locations.

White shaded arrows indicate inferior or missing sensors. This OEM is closer than the last, but is still using the wrong sensors in the first three locations. Generator problems will go undetected, as will those on the main bearing and planetary section.

• • •

•

CMS is not the developer’s core competency The company selling the CMS has been working with it for a short time The particular CMS only works for the company selling it. There are accepted standards for conducting vibration monitoring. Only about three companies certify in vibration to the ISO vibration standards. But most companies that market wind-specific CMS do not follow the standards and instead take their own approach to condition monitoring. So when someone says “this is our approach,” it is not the way other industries or certifying bodies approach CMS. What’s more, it is usually wrong which is why it’s an issue.

The company selling the CMS has experience only in wind. Company experience is limited in other markets. CMS companies that provide to other vertical markets have to make products

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that work in all markets and applications.

Therefore, the specification and adherence to standards are better because the equipment must work in a paper mill as well as for Boeing.

If you buy a particular CMS system, you will have to deal with it for the life of the project. That experience will be either good or bad, so it is important to understand what you are buying. There seems to be two fundamental truths or indicators of the legitimacy of the CMS provider: Did the installer put the right sensor in the right location?

Here is a comparison between a few OEM installed, condition-monitoring systems. The table is based on proper sensors in the proper location for fundamental and adequate measurement and detection.

Information in the table begs the question: Why are there seven different approaches on basic sensor

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Company D has two stages of the gearbox and the generator properly instrumented.

However, the sensor for main bearing and planetary sections are in the wrong locations.

Another turbine from company D has all the right locations identified, but all its sensors were inappropriate for their job. The set up provided the labeled detection rates for those sections of the drivetrain.

• • • placement and sensors selection? Out of seven CMS systems available through OEMs and aftermarket sources, it is easy to see that odds are high that you will purchase a system that does not have the proper sensors, or that they will be mounted in the wrong places. Sadly, this is the tip of the iceberg. The wrong sensor in the wrong location points to many other upstream issues from the installed CMS hardware.

Is it possible to correct the faulty installs so the system yields consistent and improved monitoring? That is possible, but why not do it right the first time? The problems described point to other systemic issues that will result in a period of missed detections and false alarms.

It should be easy for most people without a vibration background to understand that there are essentially two vibration sensors, a high speed and a low-speed sensor.

Six out of the seven brands above use or have used the incorrect sensors – high frequency sensors where low frequency sensor belong. That means they do not use low speed sensors at all, or they use inferior quality sensors. This is not a subjective issue.

Either a sensor is capable of adequately measuring below say, 60 rpm, or it is not.

Secondly, sensor placement is critical for problem detection and indications of time to failure. The CMS vendors in the table were selected because the sensors were placed in the wrong locations. A few of which are: AUGUST 2015

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On top of the gearbox – no bearings are there.

Incorrect axis, such as in an axial position that requires a radial position Missing at component locations, such as no sensor at all on the generator bearing.

When you hear someone say they have had a less than satisfactory results with condition monitoring, you now know why.

Odds are that they have a system with incorrect sensors at incorrect locations.

From the illustrations, “the right sensor at the right location” clearly has different meanings to each of the CMS vendors. There should not be this broad interpretation for correct sensor placement and use. Furthermore, operators should not need a vibrations class to grasp the idea that useful data and analysis comes from the proper sensors in the right locations. W

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ADVANCING

POWER S Made of 95%+ recyclable materials, Ioxus ultracapacitors are optimized for high performance in wide temperature ranges. They can deliver and absorb a high current and provide peak power delivery when paired with low-cost batteries or as a stand-alone product. An added benefit is that their manufacture and disposal has no detrimental effects on the environment.

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STORAGE

MICHELLE FROESE SENIOR EDITOR

with ultracapacitors

When considering energy storage, chances are you aren’t thinking about the pitch-control system in a wind turbine. But these systems, standard in most utility-scale turbines, include an important powerstorage component.

B

Because of the large rotors on utility-scale wind turbines, blades are exposed to wind speeds that vary from the highest point to the lowest. This results in uneven forces on each blade, and additional mechanical stress on the turbine and its components. A good pitchcontrol system helps manage these fluctuating forces and extends the life of a turbine.

In the case of severe weather or a grid failure, pitch systems are also equipped with power-storage capabilities that provide enough energy to return blades to a neutral position for a safe shutdown. This helps prevent damage, related repairs, or total replacement of a wind turbine.

Power storage for a pitch system needs sufficient capacity and a reliable cycle life. It also has one advantage: a smaller system need not rely on batteries. About 65% of electric-pitch systems in turbines now use ultracapacitors instead of batteries for storing electric energy and that percentage is rising with time.

The pitch for ultracapacitors Pitch controls in a turbine work by orienting the rotor blades at an angle that captures the maximum amount of wind power while acting as a safety mechanism that protects the rotor from spinning out of control.

Traditionally, turbine manufactures relied on hydraulics for these systems. More recently, many have opted for electric-pitch systems with battery backup.

Both options require costly maintenance checks that limit

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their demand in the industry. The former because of the use of hydraulic fluid and the need to monitor a system for potential hairline cracks (from the high-pressure pump), and the latter because of a battery’s high-power density and relatively short lifespan. Batteries are also heavy, which makes lugging them up an 80 or 90-m tower an unenviable job.

“Most turbine operators have to replace batteries in an electric pitch-control system every 18 to 36 months,” said Chad Hall, Co-founder and VP at Ioxus, a power technology company. “Throughout its lifetime, a battery’s efficiency drops to 70% and can go as low as 50% from the charge-discharge cycles. Fortunately, there is another option for power storage that’s efficient and trims maintenance costs.”

Enter ultracapacitors, which aren’t a new option in the wind industry. In fact, turbine manufacturers were some of the early adopters of these systems and for good reason. Ultracapacitors provide a lighter weight option than traditional batteries and offer a faster power charge with an efficiency that hovers around 98%. But it’s taken almost a decade for ultracapacitors to prove their value and gain market acceptance.

“That length of time is understandable,” Hall said.

“People felt safe with batteries. They know how they’ll react and their life expectancy. Ultracapacitors required a longer learning curve, but they’re designed to last a minimum of 10 years without maintenance in wind turbines. Of the millions of cells in use in turbines today,

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ADVANCING

POWER STORAGE I don’t actually know of a single failure in the last 10 years.” Hall expects some of the top-name turbine manufacturers to fully adopt ultracapacitors in the next couple of years.

The main reason ultracapacitors outperform batteries in efficiency and reliability is because they store energy as an electric charge rather than chemically, and so they can survive hundreds of thousands of more charge-and-discharge cycles. In a turbine, ultracapacitors also eliminate the need for slip rings when batteries are not mounted within the hub. The power-storage system is installed right in the hub, helping to reduce the weight and structural requirements usually required to fit a battery.

“When we first started in the wind industry, pitch-control systems used what they called 16V/58F modules that consisted of six 350-Farad cells in series,” Hall explained. The Farad unit measures how much electric charge is accumulated on a capacitor.

He said wind turbines could include up to 90 per blade and that each module had six bolts and two wires, which translated into countless installations hours. “This made no sense. So we looked at a lot of the pitch-control systems, which were all divisible by 80V, and we created an ultracapacitors module that can stack up… two for 160, three for 240, four for 320, and so on.”

Hall and his team were able to reduce the bolts down to a dozen or less per module stack and the wires down to two per stack, substantially cutting installation costs. This also allowed for the removal of the battery heater because ultracapacitors work at low temperatures and don’t need one.

Although this was an expensive venture in the early days of ultracapacitor-powered pitch systems, costs have dropped 99% in the last 10 years because of better materials, manufacturing, and

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The 300-kW, 150-kWh energy storage system for the Tallaght Smart Grid Testbed in Ireland uses ultracapacitors and lithium-ion batteries to support grid stability in residential and industrial settings. The microgrid stabilizer from Freqcon addresses the electricity variability challenges that accompany high renewable-energy penetration.

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Wind-farm Bus

ESA Trailer

Phone

The Tallaght Smart Grid Testbed will show that energy storage is the key to minimizing grid instability issues as more renewable energy sources come online

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An electronic shock absorber (ESA), the capacitor in this diagram acts as an interface between a wind farm and the utility grid. As the generation of wind power to the electrical grid increases, the grid becomes more susceptible to voltage fluctuations associated with rapid wind-speed changes. Wind speed changes of up to 10% in a few seconds are common at most wind farms. An ESA can minimize the effects of these changes on the power quality coming from the turbines or wind farm.

Ultracapacitors are contained within an outbuilding or trailer near the wind farm and provide the energy storage component or the “voltage-smoothing” interface. Depending on the size of the farm, this concept can also work with individual turbines. Rather than a single interface between the wind farm and the utility grid, each individual turbine can provide voltage buffering or smoothing to the grid.

processing. “Historically, we had to rely on return on investment just like turbine owners. But today ultracapacitors are at cost parity with a lead-acid battery at an original installation,” Hall said. He added that battery prices have also come down, but only by 30% and without a significant change in performance.

Nevertheless, Hall doesn’t deny there is a place for batteries. “They are workhorses and will always be around. The choice isn’t necessarily one or the other, ultracapacitors or batteries. There’s a place for both.”

Hall gives the example of a wind farm that could integrate storage using an ultracapacitor to handle the short, under 30-second charges and a battery that could handle the long-term energy storage needs. “Ideally, both devices would work in combination,” he said. “Battery life extends two to eight times when an ultracapacitor works alongside it, taking care of all of the high discharge and recharge currents.

Then the battery can do what it does best: maintain long-term storage.”

Combining storage systems In Ireland, a country that has a target goal of 40% renewables within the next five years, ultracapacitors are already working alongside batteries to support the grid in an energy storage system.

The Irish distribution network is essentially an island grid that relies heavily on wind power, except for two smaller power lines that connect it to Great Britain. More than half, and on some days up to 75%, of its electricity is generated from renewable sources. Impressive but with variable wind speeds, the grid needed stability measures.

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developer Freqcon, Ireland deployed its first combined ultracapacitor and energy storage facility last year for the Tallaght Smart Grid Testbed in South Dublin County.

The Testbed uses a microgrid stabilizer for voltage and frequency stability, in combination with lithium-ion batteries and ultracapacitors for active power support in the grid’s distributed network.

“The Tallaght Smart Grid Testbed will show that energy storage is the key to minimizing grid instability issues as more renewable energy sources come online,” said Wolfgang Beez, Senior Product Marketing Manager of Maxwell Technologies, a U.S.-based producer of power delivery and energy storage solutions.

Maxwell provided the ultracapacitors for the project. “With an increasing number of new-generation capacity stemming from wind and solar farms, advanced energy storage systems that use technology, such as ultracapacitors, are critical for the success of reliable distributed energy generation.”

Norbert Hennchen, CEO of Freqcon agreed. In a press statement about the project, he said: “The market for grid-tied energy storage systems is growing, and fast frequency response is a valuable system service to the grid. Ultracapacitors are the ideal technology to do this.”

The electrostatic energy storage mechanism of ultracapacitors lets them charge and discharge in fractions of a second and perform over a broad temperature range (-40° to +65°C). But an ultracapacitor can store only about five percent as much energy as a lithium-ion battery of similar size. Working together, the two can optimize power use, the ultracapacitor taking care of the rapid high-discharge and recharge windpowerengineering.com

SOURCE: George Washington University

MATERIAL COSTS Recent advancements in producing materials such as graphene, which is used in the manufacture of ultracapacitors, might lead to greater adoption of the devices in electronic and storage systems. Quite accidentally, researchers at George Washington University's MicroPropulsion and Nanotechnology Laboratory discovered a less expensive hybrid-composite material by unintentionally mixing carbon nanotubes and graphene. The combination has the best qualities of both forms of carbon and resulted in a superior ultracapacitor.

According to the report findings: “Both carbon nanotubes and graphene have superior electron mobility, making them perfect for meeting the ultracapacitor’s need to quickly deliver power and just as quickly recharge, thus combining the energy storage capacity of a battery with the quick energy delivery and recharging capabilities of a capacitor.”

current, and the battery standing up to the long-term storage needs.

“By combining two complementary technologies to provide a service that neither would be able to do as efficiently alone, you come up with a cost-efficient, fast-frequency response system that also provides backup power with the batteries,” said Beez. “We are looking forward to seeing more of these systems deployed in the future.” W WINDPOWER ENGINEERING & DEVELOPMENT

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Demand in the U.S. composites market is expected to grow to $10.3 billion by 2019 at a compound annual growth rate of 6.6%.

Point-of-use heating is one idea that can improve productivity and keep the market growing.

High-performance composites consist of carbon, Kevlar, or glass fibers impregnated with a resin system and cured into a shape using various molding methods. They are extensively used in wind equipment, and most commonly in turbine blades. Carbon fiber is slowly gaining popularity over glass fiber for use in blades, especially as wind turbines grow in size, because of its lighter weight and greater durability. Lighter blades require less robust turbine and tower components, so the cascading cost savings justify the higher price of carbon.

One widely used resin-fiber intermediate is called “prepregs”– pre-impregnated fiber sheets formed when a thermoset heat-curable resin is combined with carbon fiber and partially cured in a continuous filming impregnation process. Prepregs are made in factory-controlled conditions to ensure that the carbon fiber-to-resin ratio is tightly managed and that the resin formulations have consistent quality.

For decades, prepregs have helped make critical composite parts for demanding applications, such as in aerospace. But as demand for highperformance composites grows, traditional prepreg processes must also keep up by transforming from basic batch operations into more efficient and higher-capacity automated processes.

Many resins used in high-performance composites have molecular make-ups that result in a thick or semi-solid product at room temperature. It’s therefore necessary to heat and mix the composites into the proper formulations before processing into prepreg intermediates. One idea to help

increase capacity is to simply speed up the resin pre-heating to keep up with the higher demand of larger scale prepreg processes.

The benefits of a faster heating process include higher quality end products, improved prepreg production logistics, and reduced resin waste, which is common with lengthy heating and reheating cycles. Point-of-use resin heating is a continuous process that offers a high-volume, cost-saving alternative to traditional bulk-heating methods. Heating only what’s needed when needed is the primary goal of point-of-use resin heating, saving time and money.

The production process The prepreg resin that’s combined with carbon fiber is a formulation of different resins, modifiers, and curatives, which are mixed together and then poured or pumped onto a filmer or coating machine by hand or with the assistance of a transfer pump. The mixed resin formulation, called a premix, can either be frozen to suspend its reactivity for filming at a later time or it can be delivered to the filming process while still hot.

As the resin mix is coated onto a base release paper, a continuous supply of dry carbon-fiber strands are pressed into the resin film, producing a prepreg. The prepreg then continues down the coating line where it’s cooled and cut into sheets or rolled up. Once the carbon fiber and resin mix cools, the resin solidifies and enters what is known as the “b-stage,” an intermediate stage where the resin is partially reacted and stable for a short period of time.

MAC LARSEN Director of Application Development Graco Inc.

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Saving

TIME & COSTS The typical inline meter-mix system is supplied by a point-of-use drum heater. The reactive hardener is metered accurately with the hot resin, and the two components are mixed inline using a static mixer, which provides a constant temperature flow of freshly mixed prepreg resin to the filmer.

To ensure the highest quality prepreg product with the correct carbon fiber-to-resin ratio, resin premixes are created in limited volumes but multiple times daily and delivered to the prepreg filming process.

A few problems with drum heating Resins are usually supplied in five-gallon (20-liter) to 55-gallon (200-liter) drums.

They are heated in the drum using an external heating source, such as an oven or a clamshell drum heater. The heating process can take as long as 24 to 48 hours in 55-gallon drums to ensure the viscosity is reduced enough for pumping into a prepreg resin batch-mixing operation.

Once the pre-heating process begins in the drum, higher performance multi-functional resins will advance or self-polymerize because of their autocatalytic or reactive nature. If these resins are kept hot for an extended period, they will age beyond use. Even if a 55-gallon drum of resin is heated for production but only partially used, the remaining material is likely no longer within specification and is wasted.

Precision is key during this process.

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means that production and logistics are planned in advance to ensure success.

But heavy project demands often means there isn’t enough heating space to stage the drums of material required for a day’s workload. It’s easy to see that this is when point-of-use heating becomes the necessary and more cost-effective option.

The point-of-use solution When using point-of-use drum heaters, the drums of ambient temperature resins can move from storage shelves to a platen heating system where the resin is melted and pumped “on the fly” out of the drum.

This lets the remaining drum contents rest at ambient temperatures, safe from advancing or aging. Once a drum is emptied, a second or tandem platen heating system can take its place, ensuring an uninterrupted supply of hot resin to the batch-mixing process. Point-of-use heating eliminates the need for large ovens and extended heating times.

Temperature matters at every stage of production. If premix temperatures vary when added to the coating head of the filmer, coating thickness will also vary and

affect the final resin-fiber ratio of a prepreg product. Viscous shear is the reason.

Viscous shear is the friction that occurs between boundary layers (knife and roll) at a certain flow velocity (coating line speed). As the viscosity changes so does the shear, which affects the deposit of coating thickness. A tightly monitored and constant carbon-fiber feed down the line ensures a proper resin-fiber ratio. But if the resin temperature increases, the viscosity decreases and results in a reduced viscous shear through the coating slot. When shear diminishes, more resin premix can flow through the gap (under the knife), resulting in greater resin deposition on the release paper and a resin-rich prepreg.

The opposite is also true. If premix temperatures drop, viscosity increases and creates more coating head shear and reduced resin thickness. If large enough, variations in thickness lead to higher monitoring and labor costs because a technician must constantly adjust coating gaps and manage rejected prepreg materials.

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Graco’s Therm-O-Flow series of hot-melt supply machines heat and transfer only the resin that’s in close proximity with the machine’s heated platen. This leaves the rest of the drum contents at ambient temperatures, safe from advancing or aging.

Resins are usually supplied in five-gallon or 55-gallon (as shown here) drums, which are heated using an oven or a clamshell drum heater for up to 48 hours.

Once heated to the right consistency, the resin is then pumped into a prepreg resin batch-mixing operation for further processing.

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Point-of-use heating pumps provide an alternative to help counter temperature and shear variation.

These pumps form a constant resin premix temperature that’s delivered to the coating head, leading to a more controlled prepreg manufacturing process and ultimately higher yields.

They also enable the use of inline resin metering and mixing processes.

Inline meter mix technology leverages drum-platen heating by supplying an accurate resin flow to a continuous inline mixing process and eliminates batch mixing of reactive materials. The continuous mixing process can also increase prepreg production by enabling the use of windpowerengineering.com

faster reacting resin systems that cure quicker. The in-line meter mix system eliminate the time-consuming cleaning process of reactive materials in expensive batch-mixing vessels.

With reduced waste and improved logistics, point-of-use resin heating offers a faster, more effective process that can easily incorporate inline mixing. As demand from various industries, including wind power, grow and as sustainability measures become integral to companies corporate mandates, point-of-use resin heating will likely become the next logical industry standard in the world of composite production. W WINDPOWER ENGINEERING & DEVELOPMENT

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The digital twin from GE is one idea for improving wind farm O&M. For it, a physical turbine (opposite page) would have a perfect working digital version to which the physical model would be compared. Differences in power output, for example, would signal a turbine in need of attention.

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EMERGING IDEAS that promise to

cut costs from O&M

Paul Dvorak Editor

Several recent ideas that promise to make wind farms more profitable include the possibility of wind turbines that learn, on-demand guidance for maintenance and troubleshooting, and a turbine’s perfectly performing digital twin.

T

he recent cost of wind turbines have stabilized after a significant reduction over the past 15 years and will likely remains so through 2017 if our consultants’ crystal balls are accurate. The good news, however, is that each new model brings another bump up in reliability. For instance, one recent 2.3-MW turbine boasts of having no slip rings. Fewer components generally spell lower maintenance costs.

Although such effort will also continue to remove cost from towers, control equipment, and other components, if the price of wind-generated power is to drop further, it will be necessary to take cost out of operations and maintenance. The recent WINDPOWER 2015 Conference dealt mostly with that issue.

One panel presentation in particular, chaired by UpWind Solutions CEO Peter Wells, dealt with advanced ideas for taking cost out of O&M tasks. “LCOE for the wind industry has dropped by over 50% in the past five years, with some of this reduction coming from improved OPEX – lower operating expenditures,” said Wells. “Even so, many asset owners continue to look for further reductions in OPEX, by 20% or more, especially in this post-PTC era.”

The presentations in Wells’ session discussed the O&M areas that are most ripe for exploration, such as the possibility of turbine’s learning, on-the-spot training, and one OEM’s take on building a smarter wind farm.

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Where it’s possible to cut costs?

Bloomberg New Energy Finance’s Dan Shurey suggested that the average LCOE of unsubsidized U.S. power was at $48/MWh while the PTC was in effect, but that figure will rise to $60 with the end of the tax credit. Shurey predicts that it will be $65.5/MWh in 2017, $27/ MWh above forecast realized revenue in this year. (Realized revenue is the effective revenue an average wind project would receive, considering the correlation between average hourly and seasonal wind speed characteristics and average hourly/seasonal power pricing).

In other words, the levelised cost of wind will be higher than the average revenue wind receives, without a PTC. Some gains will come from new technology. For instance, his analysis of average global capacity factors showed that efficiency improvements have raised capacity factors by about three percentage points through 2015.

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However, combine that with increased competition for O&M services that come hub heights, and the capacity factors from OEMs, ISPs, and in-house O&M jumped to 34%. The implication is that teams. It’s also possible to improve turbine complex engineering solutions are not availability with efficiency gains, and always needed to improve production. downtime reductions that could come Shurey’s initial illustration LCOE from non-disruptive inspections and fixes. components: Capex and turbine prices show a Many asset owners continue breakdown of the LCOE into several categories. The latter to look for further reductions three account for 53% of LCOE after 2017, with the weighted in OPEX, by 20% or more, average cost of capital (WACC) especially in this post-PTC era. being the largest. In nonaccounting terms, WACC is the rate that a company is expected to pay Further O&M reductions can come from on average to all it security holders to dynamic and real-time smart scheduling finance its assets. of O&M tasks. To reduce the WACC, a So how can technology huge portion of opex costs, he suggests improvements help reduce O&M costs? reducing the risk of failure of major Shurey has several ideas. For example, components and a steady cash flow. by automating service and condition monitoring, by fault prognosis and Harnessing big data machine learning, and by increased There is a lot of buzz around the idea of big data. The sense is that one day, mining huge quantities of data generated by wind turbines and surrounding facilities might provide actionable information. But GE’s Andy Holt said that useful information from big data is here and now. “The process is complicated, but the information the site manager needs is simple.” With that, Holt introduced the concept of the digital twin. “It’s not a complicated concept. The idea is that the digital twin would be producing a predictable and optimal amount of power given the wind and weather conditions at the moment.

If the physical twin is not producing a similar amount, then it needs a technician’s attention.

“Each turbine we install and commission today has a digital twin. The amount of processed data is enormous when you consider at a single wind farm we can now install up to 20 different turbines by varying the tower heights, generator ratings, and different blade lengths, all with the same machine head.

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The new 2-MW platforms from GE now include Digital Twin controls. Combining hardware, software, and data analytics is one way to boost AEP, suggests the left panel in the slide.

Other improvements to operation and future enhancements are coming. The company says it commissions a turbine every two hours.

So while optimizing a wind turbine is good, optimizing a wind farm is better.”

Holt suggests that great changes are coming to the technician and site-manager level. “They will have tools to help them do things better that day.

For instance, they would receive a list of actionable items that lets the site manager examine it and say, ‘we should climb turbines 7 and 9 today because those machines are asking for attention.’”

Sounds great, but does it work? GE has already tested part of this concept with its PowerUp Services, a combination of hardware and software improvements that increase AEP on

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A technician faced with an unfamiliar task and access to a database through Ryan Junee’s Wearable Intelligence, could ask the database for assistance with specific voice commands. Using Google glasses, the worker would see and hear instructions for particular task, such as blocking and bleeding a particular valve.

existing turbines. Holt says the company has implemented PowerUp on about 4,000 turbines globally so far – one of the best performing sites generated an 8% AEP increase over last year.

“So when the newest 2-MW configurations come out, such as the 2.0-116 and 2.3-107, they will be easy to service in big nacelles thanks in part to big data.”

While his presentation pointed to a productive future, Holt added that the wind industry as some catching up to do. “For instance, in oil & gas industries, 95% of outages are planned versus 5% unplanned. In wind today, the percentages are 50-50. We have to improve that.”

On-the-spot training and troubleshooting

Wind technicians receive a good deal of classroom and hands-on training before an operator lets them go up tower. Should they encounter an unfamiliar condition, they may phone their supervisor or a more experienced tech. But if that person is unavailable, what then?

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other devices such as phones and tablets because they provide instant information.

But Junee says the glasses work best.

For his presentation, Junee showed a video to demonstrate the potential of instant information to oil-field workers performing non-routine tasks, such as clearing pipelines by carrying out a long

pressure reading or other technical data. The software is intended for collaboration of workers in remote field locations, such as wind technicians.

In the video, the field-site manager made an insightful comment: “We are in the middle of nowhere and yet we have information at our fingertips.” This is significant because the time it takes to acquire information also has a cost.

Capability of this sort could let experts remotely view what the worker sees, and chat with the worker doing the procedure.

The software behind the development, called Director, comes from Junee’s company. It is navigated with voice commands and head gestures. He says it also captures in-field data in the form of dictated messages or point-of-view perspective photos and recorded videos.

The software also records extensive metrics for workforce analytics, such as the length of time taken for the operator to complete each step, which can be used for audit, compliance, and continuous improvement.

What if wind turbines could learn?

Artificial intelligence is hot topic today and likely to get hotter. Letting

They would receive a list of actionable items that lets the site manager examine it and say, ‘we should climb turbines 7 and 9 today because those machines are asking for attention.’ sequence of instructions. The video shows a small but readable screen that the Glasses present the wearer.

The worker then talks to his information base with commands.

For example, the worker initiates the instructions with the command: “Mainline,” and the system responds with information, such as that the Mainline valve is open. The sequence continues with other commands, to which the system responds with more information, sometimes with a real-time

machines learn or anticipate from their “experience” would be one application for the possibilities presented by Microsoft’s Director for Machine Learning and Data Science Solutions Vijay K. Narayanan. He suggested several reasons to let wind turbines learn.

For instance, let a machine learn behavior when: • It cannot be coded, such as learning to recognize speech, images, or gestures, as when troubleshooting a problem.

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• It cannot be scaled, such as making recommendations for maintenance.

• The machine has to adapt to an unusual situation. What could be more unusual than variations in the weather?

Also, learning a behavior would be useful when it cannot be tracked. Narayanan’s example here was for artificial intelligence in gaming and robot control.

Although Narayanan was short on wind-industry examples, it is not difficult to see a few applications to the wind industry. And at this point, it’s easy to see his presentation crossing into others. For example, GE’s Digital Twin sounds as if new turbines can already learn. This is likely the first step to machines fixing themselves or at least helping diagnose their ailments. One suspects that wind technicians will not complain too much if they can avoiding one 100-m tower climb each day.

For machine control, monitoring and alerting may be interesting. “At Microsoft, we have thousands of users.

How will we track their data? Background monitoring could track the health and availability of company services,” according to Narayanan.

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An operator’s perspective

Crystal balls and untested tech are fun, but what about the real world? EDP Renewables Brian Hayes brought the operator’s perspective to the panel.

He said the challenge is to simply find which turbines are offline, need repair, and are underperforming. “Getting much more proactive with offline and faulted turbines has enabled us to improve availability. We use statistical comparisons of one turbine to another to identify poor performing turbines,” he said. The company estimates gaining 3 to 10 points in availability by using data to focus efforts on turbine performance,” he said. From 2010 to 2011 the company focused on efficiency, how to get more power out of turbines. Some improvements came from software, such as improving pitch-control algorithms.

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Videoscopes

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Using the Close-Focus tip, fine cracks are detected inside a combustion chamber.

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What is the pressure in the line?

Just ask and Wearable Intelligence, when properly configures, will tell.

(LEFT): Microsoft’s Narayanana said the plots are power demand and predictions from a region in China. The plot in black is true energy consumption while the red was an earlier forecast of consumption. Narayanan suggests that the red line tracks the black line with good accuracy, and that is something grid operators should find useful.

True

Source: Microsoft

Forecast

WHAT DO YOU THINK? EDPR has also considered and made airfoil modifications because not all blades types are optimized at the factory. “We see opportunity particularly on machines from 2007 to 2012 and are experimenting with vortex generators, chord extensions, those types of things,” says Hayes.

Physical adjustments mean going back to the data to determine what gains have been made. “It is difficult because there are lots of variables and data,” he says.

Then there is the recent lidar technology for identifying a yaw misalignment. How to make best use of it will also take some research and testing,” he suggests.

On cost reductions, the thing EDPR is really excited about is condition monitoring. “We took a big step this last year by retrofitting turbines that are five years old and out of warranty with CMS systems. Results have been extremely positive. For certain projects, the payback is almost complete on the CMS equipment,” he said.

Technology has also had a meaningful impact to test and inspection work. “We are using Infrared (IR) scans for transformers 56

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and other high voltage connections. There is also technology available for conducting an IR scan of rotating blade that would identify its hot spots and where repairs are needed, all without taking the turbine offline. So there is a lot of other technology coming on and we are examining how we might embrace it.” W

Connect and discuss this and other wind issues with thousands of professionals online

www.windpowerengineering.com

AUGUST 2015

8/13/15 9:48 AM

E Q U I PME N T

Precise, quick, and quiet bolting TORKWORX www.torkworx.com

Gearbox exchange and replacement services Moventas www.moventas.com The Moventas Reverse Engineering Program works when the company sends out a refurbished replacement gearbox in exchange for a damaged gearbox. The damaged gearbox, regardless of manufacturer, enters the program

The RAD E Series Electronic Pistol Grip Torque Wrenches are

and eventually becomes a part of the Gearbox Pool to be

capable of data collection, angle measurement with 3% accuracy,

used for future turbines. The company says

and torque values up to 6,000 ft-lb. With a lightweight and

replacement gearboxes may

ergonomic pistol grip, the E Series decreases tightening times

be on site within three days.

by 60% through continuous torque. What’s more, a low-profile handle helps reduce operator fatigue. The wrench works at lownoise levels, around 75 db.

Sustainable rust protection Wind Secure www.windsecure.com Rust Bullet coatings from Wind Secure are single component, moisture cure primers with high performance protection for steel and iron applications.

Fine filter for turbine gears CC-Jensen www.cc-jensen.com

The coating has been primarily tested on wind turbine foundation anchor bolts with plastic caps and grease. The coating works well in a variety of environments including onshore,

C.C. Jensen’s HDU 15/25 PV offline, fine-filter series has

offshore, or underground.

large by-pass valves that ensure filter operation at low temperatures. The filer has a pump yield of 45 liters/h, a standard filter element of BG 15/25, and a 0.13 kW power consumption. Filter inserts from C.C. Jensen have a filtration degree of 3 μm absolute and 0.8 μm nominal.

AUGUST 2015

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®

Delivering Education and Opportunities for the Wind Energy Industry

Make your plans to attend these AWEA educational events: AWEA Wind Resource & Project Energy Assessment Seminar 2015

AWEA Wind Energy Finance & Investment Seminar 2015

September 16 – 17 I New Orleans, LA

October 14 – 15 I New York ,NY

AWEA Offshore WINDPOWER® 2015 Conference & Exhibition

AWEA Wind Energy Fall Symposium 2015 November 3 – 5 I Albuquerque, NM

September 29 – 30 I Baltimore, MD

AWEA Wind Power on Capitol Hill 2015 October 6 – 7 I Washington, D.C.

VISIT www.awea.org/events FOR MORE DETAILS.

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AD INDEX

AeroTorque........................................................ 5 Amsoil Inc...................................................... IBC AWEA................................................................. 25 Aztec Bolting...................................... Cover, 12 Bachmann electronic Corp...........................13 BGB Technology Inc.......................................21 Campbell Scientific, Inc................................ 37 Castrol Industrial North America Inc........IFC Dexmet Corp..................................................... 9 Gradient Lens Corp........................................ 55 HYTORC........................................................... 23 Mattracks, Inc. ................................................ 27 Nord-Lock Group.......................................... 53 Renewable NRG Systems............................. 25 Siemens........................................................... BC Women of Wind Energy.................................15

SALES

LEADERSHIP TEAM

VP Sales Todd Tidmore 512.626.8263 ttidmore@wtwhmedia.com @wtwh_ttidmore

Regional Sales Manager Neel Gleason 312.882.9867 ngleason@wtwhmedia.com @wtwh_ngleason

Regional Sales Manager Megan Hollis 440.821.2941 mhollis@wtwhmedia.com @wtwh_Megan

Publisher Mike Emich 508.446.1823 memich@wtwhmedia.com @wtwh_memich

Key Account Manager Jim Powers 312.925.7793 jpowers@wtwhmedia.com @jpowers_media

Regional Sales Manager Courtney Seel 440.523.1685 cseel@wtwhmedia.com @wtwh_CSeel

Business Development Michelle Flando 440.381.9110 mflando@wtwhmedia.com @mflando

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

Regional Sales Manager Tom Lazar 408.701.7944 wtlazar@wtwhmedia.com @wtwh_Tom

Regional Sales Manager Jessica East 330.319.1253 jeast@wtwhmedia.com @wtwh_MsMedia

EVP Marshall Matheson 805.895.3609 mmatheson@wtwhmedia.com @mmatheson

CONNECT WITH US! NEW

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AUGUST 2015

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(FAR LEFT): This GE engineer is heading up the ecoROTR’s 97-m space-frame tower, which is also a prototype. It holds one of GE’s most powerful machines, the 1.7-MW wind turbine, and the attached 18.3m experimental dome.

(LEFT): If experiments confirm wind-tunnel data, the 20,000-pound dome could lead to larger and more efficient turbines, especially in remote, hard-to-reach locations.

Domed rotor holds promise of 3% more wind power SOME HAVE LIKENED IT TO A UFO stuck atop a utility tower and others simply call it “big nose.” Granted, it’s not your usual wind turbine but GE, the engineers behind a unique new design, are more concerned about efficiency than aesthetics.

The design started out with a styrofoam ball and a toothpick when GE scientists were challenged to build a rotor that could harvest more wind. The result is a lone prototype that today rises some 137-plus meters (450-plus ft.) from base to blade tips, and stands out amongst a sea of conventional turbines in California’s Mojave Desert.

It’s called the ecoROTR for Energy Capture Optimizer by Revolutionary Onboard Turbine Reshape.

GE started testing the 20,000-pound domed ecoROTR in May of this year as part of the company’s ecomagination initiative, which aims to build cheaper machines with a lower environmental impact. ecoROTR was designed with the intent of addressing two significant wind-turbine issues: efficiency and size.

The dome’s operating theory goes like this: Wind hitting near the center of rotor is basically lost, or according to GE “wasted.” The team of GE scientists figured if they could deflect the wasted wind from the hub, the aerodynamic

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sections of blade could still harvest its power. The engineered “nose” or aluminum dome can also mount on larger rotors without further adjustments.

Data from a wind tunnel test showed the potential for a 3% improvement in performance. This might not seem like much but GE maintains that improvement multiplies across an entire wind farm, enough so that they took a model turbine to the University of Stuttgart in Germany for more testing. This led to the desert prototype, a 18.3-m (60-ft.) experimental dome attached to the 100-m diameter rotor on a 1.7-MW GE wind turbine. Even the tower is a prototype.

Instead of traditional rolled steel sections, the 97-m (318-ft.) latticework or space-frame tower is wrapped in a polyester-weave coat. Before it is constructed, tower girders or support beams easily load into shipping containers and onto ordinary trucks. According to GE, the steel beams more easily bolt together in places that were previously hard to reach during tower construction.

It will take until the fall of this year before data is fully collected from the ecoROTR’s prototype. Until then, we’ll have to wait and see if a UFO-like aluminum dome could serve as the future model for wind turbines. W

www.windpowerengineering.com

AUGUST 2015

8/13/15 3:34 PM

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The new Siemens SWT-3.3-130

Low wind, high yield What is the best way to turn a low-wind site into a viable energy producer?

May we present the SWT-3.3-130? It offers unmatched yield in low wind conditions, combining for the first time two Siemens innovations: the swept area of a 130 m rotor and our D3 direct drive technology.

It builds on the success of our D3 platform of onshore turbines, exploiting tried and tested features from direct drive to aeroelastically tailored blades. And it offers you a choice of tower heights up to 135 meters to suit your particular site conditions.

The result is something truly remarkable: more from less.

siemens.com / wind

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