Maine Offshore Wind Buoy Looking Up

When the DeepCWind Consortium at the University of Maine launches the 1:8-scale VolturnUS into the Penobscot River this Friday and then takes it out to sea, it will mark the deployment of the first grid-connected floating offshore wind turbine in U.S. waters. But there’s more to this project.

The consortium will also deploy a buoy that could represent a big advance in measuring offshore wind speeds, a matter of considerable concern for parties considering investing in offshore projects.

maine lidar buoy offshore wind

image via University of Maine Advanced Structures and Composites Center

Mind you, there are already more than a few sources for wind speeds off the Maine coast, through various buoys that bob around the Atlantic. But they capture wind speeds at or just above the water’s surface; turbines are planned for perhaps several hundred feet up.

So what they’ve done at the university’s Advanced Structures and Composites Center, working with industry players, is develop a buoy that uses light detection and ranging – LIDAR – to measure wind speeds up to 200 meters high.

“This partnership between UMaine and our private industry leaders will advance resource assessment technology and will help propel the U.S. forward in deepwater offshore wind technology development,” Habib Dagher, director of the Composites Center, said in a statement. “Floating LIDAR technology, once fully validated, will provide us with a cost-effective method to assess the wind resource in areas traditionally off-limits to offshore wind developers.”

That “once validated” caveat is important; LIDAR is technology that’s becoming more widely embraced by the wind industry, but even on land there’s sometimes uncertainty about the accuracy of LIDAR readings. When those measurements are taken from a device that is rising and falling with the ocean, the challenge grows.

As the Bangor Daily News explained in an excellent story on the system, that meant “a stabilizer system had to be designed to hold the LiDAR steady while the buoy moves.”

LIDAR systems, which work like radar but use light pulses instead of radio waves, are also apparently pretty big energy sucks – which is why the Maine device comes with small wind turbines and solar panels to charge its battery and keep it operating.

Pete Danko is a writer and editor based in Portland, Oregon. His work has appeared in Breaking Energy, National Geographic's Energy Blog, The New York Times, San Francisco Chronicle and elsewhere.