Can Offshore Wind Turbines Succeed in the Great Lakes?

Can Offshore Wind Turbines Succeed in the Great Lakes?

Ice jams and bird and bat deaths will determine the answer

August 14, 2018 | Daniel McGraw | scientificamerican.com

 Aside from a small pilot program along the coast of Finland, offshore wind turbines have not been placed in waters that freeze during winter. Moving ice can act like a battering ram, pushed by storms and unpredictable currents, knocking into masts that hold up spinning blades. A major test could be coming soon in Lake Erie near Cleveland. If the six turbines in the Icebreaker Windpower project are built, they could usher in a new era of offshore power in freshwater lakes, rather than salty coastal seas, which has never been done.

The key to success will be how well Icebreaker deals with what Ohioans call the “ice shove.” Winter winds and water currents push thick ice sheets around, at times piling them 30 to 50 feet high close to shore. The sheets are known for wreaking havoc on waterfront infrastructure. Can the wind turbines survive?

SLOW START

The Icebreaker project had been held up for several years because of concerns the turning blades would kill too many birds. The plan was tentatively approved in July after Oho regulators finally determined there would be “minimum environmental impact” to wildlife. They did add more than 30 environmental caveats (pdf) Icebreaker will need to address, most of them related to bird safety.

The persistent issue has been whether the turbines would adversely affect migratory birds on the eastern edge of the Mississippi Flyway. — Read More

THE ICE TEST

Whether the tall turbine masts can survive ice sheets comes down to two primary innovations: Lake Erie is the shallowest of the Great Lakes, and averages about 78 percent ice coverage each winter, the highest of the five lakes.

Icebreaker will install an inverted cone on the towers at the water level. The idea is that by tapering from a wide flare higher up on the mast down to a narrow base at the waterline, the cone can deflect ice flowing toward the masts, pushing it down and away.

The second innovation that will be tried on Icebreaker involves how the masts will be attached to the lake floor. The “mono bucket,” a suction cup–style, circular steel bucket, 56 feet in diameter, will form the foundation.  …

The unanswered question is whether the mono buckets will hold up as the anchor for a mast that might get rocked by ice for about four months each year. — Read More

via  “Can Offshore Wind Turbines Succeed in the Great Lakes?” scientificamerican.com