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Wind turbines and bats

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Collisions with wind turbines are one of the leading causes of bat mortality in North America and Europe.  Most bat fatalities are caused by bats colliding with the rotating blades of wind turbines.  Fatalities are highest during autumn migration and on nights with low wind speeds.

According to a recent study, land-based wind turbines kill as many as 880,000 bats a year and are wiping out so many threatened bats that some species may become endangered unless preventative action is taken.

The big challenge is that bat conservation experts and scientists don’t know how to stop or reduce turbine collisions.  They don’t really know why bats are interacting with turbines to the extent that they are.  Do turbines attract bats?  Do turbines’ bright lights or just their silhouettes stimulate an attraction response?

The U.S. Department of Energy has awarded $8 million to five research centers to develop strategies for deterring bats from wind turbines. 

One of these is Bat Conservation International, which is an organization whose mission is to accelerate research to address knowledge gaps in bat ecology and behavior and develop technologies and industry methods to reduce fatality of bats at wind farms.  Among the approaches to be tested is limiting the use of nighttime lighting on wind farms to make migrating bats less likely to fly through blades. 

Another team at Boise State University is designing ultrasonic noisemakers to scare off bats. 

In announcing the new program, the Department of Energy states that wind energy must be appropriately and responsibly sited, which includes the protection of wildlife and their habitats.

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Experts Seek to Spare Bats From Wind Turbine Collisions

Photo, posted January 10, 2013, courtesy of Tom Shockey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Giant Wind Turbines | Earth Wise

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Wind turbines keep getting bigger and bigger.  The reason is that the power a wind turbine can theoretically generate is proportional to the disk-shaped area swept out by its blades.  So, the bigger the blades, the more power can be produced by a single turbine.

That being said, real-world turbines don’t achieve their theoretical power output because they have limitations on efficiency.  Things like rotor blade friction and drag, gearbox losses, and generator losses limit the actual power output of a turbine. 

Despite all of these things, the latest and greatest wind turbines are absolutely enormous and produce almost unbelievable amounts of power.  Chinese manufacturer MingYang Smart Energy has recently unveiled an 866-foot tall, 16-megawatt capacity offshore wind turbine.  This narrowly exceeds both the Vestas V236 Turbine announced earlier this year and GE’s Haliade-X Turbine, rated at 15 megawatts and 14 megawatts respectively.

The rotor diameter of the giant Chinese turbine is nearly 800 feet, set by its 387-foot blades that sweep out an area of nearly 50,000 square feet.  A single one of these turbines can generate 80,000 MWh of electricity in a year, enough to power more than 20,000 households.  (It boggles the mind to consider that just one rotation of the blades of such a turbine can power a couple of homes for an entire day).

Offshore wind farms choose the largest wind turbines in part because of the high cost of installing turbines and transporting the electricity.  It is preferable to build fewer turbines because fewer towers, cables, and ground anchoring systems need to be constructed, making the project less complicated.

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This 264-meter tall offshore wind turbine is now the largest of its kind

Photo, posted November 19, 2015, courtesy of Scott Flaherty / USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Recyclable Wind Turbines | Earth Wise

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The blades of modern wind turbines can be longer than the wing of a Boeing 747. Their useful lifetime is perhaps 20 years and after that, they can’t just be hauled away.  They end up being cut up with special industrial saws to create pieces small enough to be strapped to a tractor-trailer.  Then, they end up in landfills.  There are thousands of blades being removed each year and those numbers are growing.

Wind turbine blades are currently manufactured using thermoset resin, which cannot be recycled.  It is also energy-intensive and manpower-intensive to produce.

Researchers at the National Renewable Energy Laboratory in partnership with Arkema Inc of Pennsylvania have demonstrated the feasibility of using thermoplastic resin instead to make wind turbine blades.  That material can be recycled and can also enable longer, lighter-weight, and lower-cost blades.  Using thermoplastic could also allow manufacturers to build blades on site, alleviating the problems of transporting ever larger turbine blades.

Current blades are made primarily of composite materials like fiberglass infused with thermoset resin.  The manufacturing process requires additional heat to cure the resin, which adds cost and time.  Thermoplastic resin cures at room temperature and requires less labor.  With regard to recycling, thermoplastic resin, when heated above a certain temperature, melts into its original liquid resin and can be reused. 

NREL has demonstrated the feasibility of the thermoplastic resin system by manufacturing nearly identical blades using both the standard materials and the thermoplastics.  NREL has also developed a technoeconomic model to evaluate the cost benefits of using thermoplastic resin.

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News Release: NREL Advanced Manufacturing Research Moves Wind Turbine Blades Toward Recyclability

Photo, posted June 28, 2008, courtesy of Patrick Finnegan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Toughest Beetle Of Them All | Earth Wise

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In 2015, UC Riverside materials scientists placed a mottled black beetle in a parking lot and ran it over with a Toyota Camry.  Twice.  Crushed beneath the wheels of a 3,500-pound sedan, the inch-long insect made it through without a scratch.

For the past five years, a group of scientists have been studying this remarkable bug, which has the splendid name of the diabolical ironclad beetle. Using a combination of advanced microscopy, mechanical testing, and computer simulations, the researchers have figured out the secret of this beetle’s crush resistance.

The beetle’s super-toughness lies in two armorlike structures called elytra that meet in a line, called a suture, running the length of the abdomen.  The suture acts like a jigsaw puzzle.  It connects various exoskeletal blades – the puzzle pieces – in the abdomen under the elytra.   These structural components can act in different ways.  The interconnecting blades lock to prevent themselves from pulling out of the suture.  The suture and blades delaminate, leading to a graceful deformation rather than catastrophic failure.  These strategies dissipate energy to circumvent fracturing.

The researchers found that the diabolical ironclad beetle – just had to say that name again – can take on an applied force of about 150 newtons, a load at least 39,000 times its body weight.  (That’s the equivalent of a 150-pound person resisting the crush of about 25 blue whales).

An ongoing challenge for structural engineering is how to join together different materials without limiting their ability to support loads.  The strategies evolved in these beetles may be applicable in gas turbines of aircraft, for example, where metals and composite materials are joined together with mechanical fasteners.   We can learn things from the toughest beetle of them all.

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Diabolical ironclad beetles inspire tougher joints for engineering applications

Photo, posted April 9, 2017, courtesy of Vahe Martirosyan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Largest Turbines In The Largest Offshore Wind Farm | Earth Wise

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The world’s largest planned offshore wind farm is going to make use of the world’s largest installed offshore wind turbines.  The Dogger Bank Wind Farm in the North Sea off the Yorkshire coast of England will ultimately generate electricity for more than 4.5 million homes in the United Kingdom.

The 3.6 GW project will cost $10 billion and will be developed in three phases, the first two of which will use 13-MW wind turbines built by General Electric.  The turbine’s blades measure 351 feet – longer than a soccer field.  The turbines stand more than 850 feet tall, which is five times the size of the Arc de Triomphe.  GE claims that a single rotation of one of these huge turbines can supply enough electricity to power the average British household for two days.  When the project is completed in 2026, it will generate 5% of the United Kingdom’s electricity.

The previous version of GE’s Haliade-X turbines, rated at 12 MW, were ordered by the energy company Orsted for installation in two forthcoming U.S. windfarm: the Skipjack Farm off the coast of Maryland, and the Ocean Wind farm off the coast of New Jersey.  The new version will be the largest turbines to reach operation in a commercial project.  Meanwhile, Siemens Gamesa has a 14 MW turbine under development.

The order for 190 of the 13 MW giant turbines for the Dogger Bank farm arrived at GE on the same day that the company announced that it will no longer supply power equipment to new coal plants.  Work on the Dogger Bank project started in January in an area of the North Sea that was previously dominated by oil and gas development.

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World’s Biggest Offshore Wind Farm Will Boast World’s Largest Installed Turbines

Photo, posted February 22, 2014, courtesy of Jonny Longrigg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

New Jersey And Offshore Wind | Earth Wise

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New Jersey intends to become a major hub for offshore wind in the United States.  The state recently announced a plan to build a 30-acre port along the Delaware River for assembling and deploying wind turbines, as well as an additional 25 acres for manufacturing facilities.   The new port is expected to cost as much as $400 million and create 1,500 jobs in southern New Jersey.

The port will be located on an artificial island that was built by the U.S. Army Corps of Engineers early in the 20th century.  The island is already home to three nuclear reactors.  No bridges exist between the island and the Atlantic Ocean, so turbines that are built at the staging facility could be hoisted upright and towed out to sea without obstruction.  Some components are as tall as 500 feet and when fully constructed on the ocean, the turbines selected for New Jersey’s first offshore wind project will be more than 850 feet tall.

A second phase of the program would add over 150 acres to accommodate extensive manufacturing facilities for turbine components like blades and nacelles.

Construction on the port is expected to start next year.  New Jersey has pledged to produce 7,500 megawatts of offshore wind energy by 2035 and to generate 100% of its electricity from renewables by 2050.  Apart from deploying offshore wind, New Jersey wants to have a significant piece of the supply chain for what is likely to be a growing industry along the northeast coast.  The state views offshore wind as a once-in-a-generation opportunity to not only protect the environment but also greatly expand its economy in a way that has immediate impacts and long-term growth.

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New Jersey Announces $400 Million Offshore Wind Port

Photo, posted September 18, 2010, courtesy of Vattenfall Nederland via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Environmental Impact of Wind Power

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A recent study by Harvard University researchers published in two papers looked at the environmental impact of installing sufficient wind power to meet all the energy needs of the US.  While doing so would be far better for the environment than burning coal, it would not have negligible impacts. 

[Read more…] about Environmental Impact of Wind Power

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