Maine could be the proving ground of a significant new renewable powerhouse for the Northeast, as scientists and builders use composites and robotics in hopes of harnessing wind and wave power.
Cianbro Corp., Pittsfield, Maine, is constructing a new $30-million Offshore Wind Laboratory, scheduled for completion in June. It has 4-ft-thick test floors with a waterproof blade-tip pit, 30 ft wide x 75 ft long x 16 ft deep, to be used as a wave basin for testing models of floating wind turbines. “It’s challenging keeping up with constantly evolving equipment technology,” says Ed Jones, Cianbro project manager. “We’re designing a facility for testing 70-foot wind blades that don’t exist yet.”
The lab will add 30,000 sq ft to the University of Maine’s 55,000-sq-ft Advanced Structures and Composites Center. Researchers will design, build and test blades, towers, anchors and foundation systems. They will test durability by simulating deep-sea conditions, including exposure to saltwater, ultraviolet rays and freezing temperatures.
Eventually, floating platforms will support 300-ft-high turbine towers in waters up to 300 ft deep and 20 to 50 miles offshore, where winds are stronger and more consistent. “Within 50 nautical miles offshore, the Gulf of Maine has the equivalent of 149 GW of wind power,” said Habib Dagher, director of the composites center, speaking in February at a wind technology forum in Boston.
The Gulf of Maine is considered a prime location for floating wind turbines due to its vast areas of deep water and strong, steady coastal winds. Recent analysis of wind and wave data culled over nine years showed that, compared to hilltop generation, offshore generation in the six- to 13-mile range produced up to 10% more energy and in the 42- to 56-mile range produced up to 33% more energy, Dagher said.
With Bath Iron Works, a shipyard in Bath, Maine, Cianbro is also building a 1/3-scale wind turbine demonstrator. It will be tested in summer 2012 at a site off Monhegan Island. The full-size turbine will be tested in 2014.
The university is collaborating with 35 members of the DeepCwind Consortium, a National Science Foundation initiative that comprises engineers, environmental scientists and manufacturers, including Technip USA in Houston, which builds spired rigs. In the past year, the lab has received $40 million in federal, state and private investment, Dagher says.
Norwegian energy company Statoil also is considering Maine as a test site for wind turbines. Last year, the state’s public utilities commission (PUC) issued a request for proposals calling for offshore power projects of up to 30 MW, with at last 20 MW to be from wind.
The plan is to install 1,000 5-MW wind turbines with an output of 5 GW of electricity by the year 2030, a benchmark based on the U.S. Dept. of Energy’s goal of achieving 20% wind power by that year, Dagher says. “Wind energy output of 5 GW is roughly equivalent to the output of five nuclear powerplants,” he adds.
Dagher claims deepwater turbines may provide cost efficiencies over shallow-water turbines. “Rather than assembling the turbines offshore … floating wind turbines can be manufactured onshore before towing them upright out to sea and tethering them to the seabed with a light cable.”
Steven Von Vogt, director of the Maine Composites Alliance, which represents 50 yacht and boat builders, adds that advances in temperature-controlled mold technology that uses resin infusion in closed-mold processes will allow for more efficient production.
“This technology can enable production of more precise blades with greater durability and longevity than fiberglass blades,” Vogt says.
Robotics will allow for the automation of fiber placement and infusion. Peter Vigue, president of Cianbro, predicts this will result in more competitive costs for manufacturing either land-based or offshore wind turbines. “This is a significant opportunity, not just for Maine but for the U.S.,” he says.
Walt Musial, principal engineer at the National Renewable Energy Laboratory, Golden, Colo., who spoke at the Boston conference, said offshore wind energy has a generating capacity of 4,000 GW over seven square miles at up to 50 nautical miles offshore.
Deepwater wind energy has 2,500 GW, or nearly two-thirds, of that total offshore wind generating capacity, he says. Once loading and other design challenges are solved, Musial predicted standardization over the next 20 years.