Maine regulators have approved construction of a 12-MW offshore wind farm, one of two offshore projects developing separate technologies to harness, by 2016, deepwater wind energy from the Gulf of Maine and link it to the state's power network.
Despite earlier concerns about the cost impact on ratepayers, the Maine Public Utilities Commission approved on Jan. 24 the $120-million Hywind project, which will involve four spar-buoy turbines, each 3 MW, tethered to the seabed off Boothbay Harbor between Portland and Rockport. The project is being led by Statoil North America, a unit of the Norwegian energy firm. Its contract with Maine utilities seals a 26¢-per-KW-hour power purchase agreement for the project. Floating wind turbines already have passed tests in the North Sea.
Commission Chairman Tom Welch says knowledge gained from the project may be most valuable to Maine. But, says Gov. Paul LePage (R), "Any policy that raises electricity costs is irresponsible. Maine has the 12th-highest energy costs in the country, and this vote forces Mainers to pay even higher prices for the next 20 years." As proposed, the project would cost Maine ratepayers about $200 million over the next 20 years, he claims.
"The [commission] was very concerned with securing supply chain in Maine and providing maximum benefits for ratepayers," says Kristin Aamodt, Hywind project manager. "As part of its contract terms, Statoil has committed to investing 40% of its capital expenditures in Maine." To optimize turbine structure, the firm boosted the size of its current demonstrator to capture more wind energy and reduced steel content. It also is streamlining design for increased efficiency and lower-cost mass production.
The Statoil project is part of a larger effort by the University of Maine's DeepCwind Consortium, a federally funded initiative comprising industry firms, utilities, researchers and non-profits that is aimed at making Maine a leader in deep-sea offshore wind technology. Habib J. Dagher—who is leading the university's wind-energy effort as a structural engineering professor at the Orono campus and director of its Advanced Structures and Composites Center—says the Gulf of Maine has nearly 150 GW of wind power within 50 nautical miles. The goal is to capture 3% of the energy by installing, 20 to 50 miles out, 1,000 5-MW wind turbines. That will generate output of 5 GW by 2030, based on a U.S. Energy Dept. goal of achieving 20% wind power by that year.
The university consortium and Statoil "are at a new stage, with a number of confidentiality agreements to drive down the cost of the Hywind project," says Dagher. He says another goal is "to identify which technology will allow for generation at 10¢ per KW-hour." Dagher says the cost is achievable once the wind farm reaches commercial size to produce 500 GW of energy, technically feasible by 2020. In December, Statoil and the university each received $4 million in federal grants for their separate 12-MW projects in Maine. Once completed, they could each receive up to $47 million over four years, if the U.S. Congress approves.
In April, the university plans to test a 1:8-scale turbine off Castine Harbor, south of Bangor. Later this summer, a larger, 300-ft-high version is set for testing off Boothbay Harbor. The total projected cost of its wind-farm project, called Aqua Ventus, is $92.2 million, including $42.7 million in private investment and $50.3 million in DOE funding. The 1:8 structure, now under construction by Cianbro Corp., will be assembled at the firm's modular manufacturing site in Brewer, Maine, says Chairman Peter G. Vigue.
"We want to design a floating system to have a double life, with turbines lasting 20 to 25 years [and] foundations lasting 40 to 50 years," Dagher says. Unlike shallow-water offshore turbines that need jack-up barges to drive them into the seabed, deepwater turbines could be towed to shore for refurbishment or upgrades, then floated back to sea. "We expect a new generation of [floating] turbines to improve significantly over the next 20 years with lighter, more efficient designs."
