Friday, April 18, 2014
Efforts to make Maine a global leader in offshore wind power are moving ahead this spring on two fronts: A small model of the country's first floating wind turbine will be installed off Castine, and testing will escalate for a pilot wind park off Boothbay Harbor.
A team from the University of Maine at Orono tests a turbine outside their laboratory recently. They plan to place the floating turbine in the ocean off the coast of Castine in May.
Photos courtesy of Habib Dagher / University of Maine
Both projects were among seven nationally that won $4 million in federal grants last year to help develop utility-scale offshore wind technologies. They are competing for a follow-up award of as much as $50 million next year for commercial operation.
Some state officials, notably Gov. Paul LePage, have criticized the higher electricity rates that help support the early stages of offshore wind power. They say the added cost won't bring enough economic benefits to the state.
But representatives of the two Maine projects say they are working to develop commercial-scale wind parks that produce power at rates that are on par with land-based generators. And a trade group says a survey it conducted last fall showed that 49 Maine companies already had generated $337 million in revenue from planning and erecting wind- and ocean-energy projects.
In late May off Castine, a team led by the University of Maine will launch a $1 million model that is one-eighth the size of its planned Aqua Ventus floating turbine. The unit is made of advanced composites to fight corrosion and reduce weight. Its hub will stand 50 feet above its floating base, with a rotor that's 32 feet in diameter. It will be moored to the sea bottom in 70 feet of water.
The turbine will be connected to the power grid with underwater cables. Its output will be a tiny 20 kilowatts, enough to power four average homes. Two dozen sensors will collect data to help researchers predict what a full-size wind park will need to survive for years in the Gulf of Maine.
"This is a very sophisticated experiment," said Habib Dagher, the UMaine professor who heads the school's Offshore Wind Laboratory.
The unit will remain in sheltered waters off Castine through June, Dagher said, then be towed to a site south of Monhegan Island for two months of tests in the open ocean.
Data from the tests will help the university -- and business partners that include Cianbro, Bath Iron Works and Iberdrola, the parent company of Central Maine Power Co. -- develop a full-scale pilot wind farm off Monhegan by 2016. It will feature two floating turbines that stand 300 feet from the water to the turbine hub.
The wind farm will have a rated capacity of six megawatts and, based on the availability of wind, is expected to generate enough power for 6,000 homes. The total cost is $93 million, with half expected to come from the federal grant and half from business partners.
Also this spring, the Norwegian energy giant Statoil is entering the next phase of testing for its Hywind Maine project off Boothbay Harbor.
Statoil launched the world's first full-scale floating turbine in the North Sea in 2009. It's using data from the experiment to refine its $120 million project in Maine. Hywind Maine would have four, three-megawatt turbines on floating spar buoys that would be anchored to the seabed in 460 feet of water.
Power could be flowing to the electricity grid by 2016. Based on studies that show average wind speed of roughly 20 mph and enough wind to spin the turbines 40 percent of the time annually, the project could generate enough electricity for more than 6,000 homes, according to Statoil.
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