Offshore Wind: Now Cheap, Getting Cheaper, Low Environmental Impact

November 24, 2017


The global shift to renewable energy is well underway, including large-scale deployment of offshore wind farms. There are already about 3,600 turbines operating along European coasts, with 14 more wind farms under development.

Even more wind energy is needed to meet the goals of the Paris climate agreement — but the push to boost European offshore wind power 40-fold by 2030 will change regional ocean ecosystems in profound and unexpected ways, according to researchers studying how the turbines affect the environment.

Most of the research stems from northern Europe, where offshore turbines have been operating since 1991. Scientists say this research can help shape plans for deploying offshore wind turbines in other parts of the world.

A recent study on the Mediterranean identified wind energy and wildlife hotspots, based partly on lessons learned in northern Europe. The science is also useful in places like Japan and the United States, where a boom in the development of offshore wind energy appears imminent.

Offshore wind developers along the US East Coast, for instance, are able to better protect endangered whales because research in the North Sea shows that construction noise temporarily displaces some fish and marine mammals; so they’re now timing building to avoid affecting those species when they are in the area, said Greer Ryan, a sustainability researcher with the Arizona-based Center for Biological Diversity.

Off the Scandinavian coast, scientist have watched some of the underwater turbine foundations gradually transform into artificial reefs, attracting mollusks and small fish that feed on plankton. This magnet effect goes right up the food chain to larger fish, seals and dolphins.

Some scientists have described these zones as de facto marine sanctuaries because fishing is often limited directly around the turbines.

Seafloor ecosystems may even be recovering in areas where fishermen have “pulverized” the seabed by dragging heavy nets along the seafloor for 100 years, said Jason Hall-Spencer, a marine biologist at the University of Plymouth.

But the long-term consequences of wind turbines on marine life are still unclear.

Targeted monitoring and studying of ecosystems could help minimize unwanted impacts on fish and marine mammals, said United Kingdom-based marine researcher Andrew Gill. He has advocated a holistic research approach that considers how all the species in an area function together.

Current policy focuses too much on studying single designated species in isolation, he believes. Ecosystem study can help determine for example migratory routes, and involve better planning on location selection.

Some effects may be unexpected. Certain species of sharks and rays, for example, use electromagnetic fields to navigate and hunt for food; and those animals react to electric energy leaking from offshore wind installations, including transmission cables on the seafloor, where the rays scuffle through the sediment in search of prey.

The impact of offshore wind farms should also be considered on the much larger scale of the ocean, said Hall-Spencer.

“The footprint is minimal compared to the vast area of the sea. The impacts are very localized and small, especially compared to the effects of fishing or warming of the oceans,” he said.

Displaced dolphins

For marine mammals, it’s the wind turbine construction phase for that has the biggest impact, according to marine biologist and consultant Victoria Todd, who has spent years studying seals, dolphins and whales around wind farms and drilling rigs.

The loud sound pulses during construction affect some species up to 12.5 miles (20 kilometers) distant.

Harbor porpoises, for example, are especially sensitive to the frequencies generated by pile driving — the process of installing poles into the ocean floor for the wind turbine foundations.

For up to six weeks, construction can push out marine mammals from large areas of their habitat, Todd said, explaining that offshore operators are bound to strict measures to try and ensure that marine mammals are not physically hurt.

But once the installations are done, the animals return, she said, adding that scientists are seeing a similar process around some decommissioned oil and gas drilling platforms in the Gulf of Mexico. There, the US government is promoting the growth of productive ecosystems with the Rigs to Reefs program.


Uncertainty surrounding wind power’s impact on wildlife–particularly the potential for deadly collisions between birds and turbines–has tarnished its image and even delayed some wind farms. Indeed, the first large offshore wind farm proposed for U.S. waters–the Cape Wind project in Massachusetts’s Nantucket Sound–has been held up in part by concerns that its 130 turbines could kill thousands of seabirds annually. Now a simple infrared collision-detection system developed by Denmark’s National Environmental Research Institute is helping clear the air.

The Thermal Animal Detection System (TADS) is essentially a heat-activated infrared video camera that watches a wind turbine around the clock, recording deadly collisions much as a security camera captures crimes. The first results, released this winter as part of a comprehensive $15 million study of Denmark’s large offshore wind farms, show seabirds to be remarkably adept at avoiding offshore installations. “There had been suggestions that enormous numbers of birds would be killed,” says Robert Furness, a seabird specialist at the University of Glasgow, who chaired the study’s scientific advisory panel. “There’s a greater feeling now among European politicians that marine wind farms are not going to be a major ecological problem, and therefore going ahead with construction is not going to raise lots of political difficulties.”

The Danish findings are also resonating across the Atlantic, casting doubt on worst-case scenarios presented by Cape Wind’s opponents. “The results make us guardedly optimistic,” says Taber Allison, vice president for conservation science at the Lincoln, MA-based conservation group Mass Audubon and an outspoken critic of ecological studies by Boston-based Cape Wind Associates.

TADS was mounted on a Nysted wind-farm turbine that was situated in the most common flight path, and during more than 2,400 hours of monitoring that concluded last fall, it spotted only fifteen birds and bats and one moth flying near the turbine, and it recorded one collision involving a small bird or bat. Furness says that this provides confidence in estimations by Danish researchers that the Nysted wind farm would kill few common eiders.


3 Responses to “Offshore Wind: Now Cheap, Getting Cheaper, Low Environmental Impact”

  1. ubrew12 Says:

    I wish there were more work on floating wind turbines. I have my own design I sent to G.E. but they weren’t interested. A good floating wind turbine would use a water-brake 100 ft below the ocean surface (where wave action can’t penetrate) to stabilize the shaft in waves. The shaft itself would be an open truss structure so water in waves could pass through it. It would not be tethered to the ocean floor, but would use wind and wave power, and on-board GPS, to maintain its position in the ocean.

    I noticed the Scottish accent of the presenter here. Nobody has done more research to make wave-power work than the Scots, but unfortunately power at reasonable cost continues to elude that renewable source, so the Scots are now at the forefront of offshore wind.

  2. Roger Walker Says:

    I’ve long suspected the Guardian of underplaying the danger and the urgency of climate disruption.

    This article ( appears to be reasonable and “authoritative”. It feels wrong, but I don’t know how to answer it.

    In reply to Katharine Viner’s long article, I recommended she watch Hansen’s 15min video:,AwarenessandSolutions.

    I know that, bottom up, lots of good things are happening. California, for example. And China, despite all the bad press they get. I know too that India is running down coal and investing massively in renewables. But, FFS, we’re still spewing out 40Gt of C02 every year and atmospheric CO2 is now definitively over 400ppm. Yet no one appears to take into account the fact that the effects of the +1.2°C we’ve already “achieved” are still working their way through the system. Talk of +2°C being “manageable” scares me shitless.

    Because I also know that Greenland ice melt was at 300 cubic kilometres per year in 2013 but AR5 took no account of it. That rate has doubled over the last 5 years. Antarctica is fraying at the edges.

    Because I know that Trump is mindlessly defunding programmes that allow us to keep tabs on what’s happening.

    Because I watched the video of that Senate hearing:

    “Is thermal expansion a factor in sea level rise?”
    “Er… I don’t know.”

    Whitehouse could barely keep from laughing! But he should have laughed He should have cast protocol to the winds and yelled at her furiously, scathingly, “You are wasting our time!”

    Please, tell me something I don’t know that might give me grounds for hope.

    Roger Walker

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