Monday, December 10, 2012

Test turbine at UMaine could be a glimpse

Test turbine at UMaine could be a glimpse into Maine’s offshore wind energy future

The man at the helm of Maine’s push to put 170 floating wind turbines in the Gulf of Maine by 2030 likens that effort to NASA’s space program.

Using that analogy, the wind turbine standing behind the University of Maine’s Offshore Wind Laboratory at the Advanced Structures and Composites Center’s could be compared to Explorer I, the first U.S. satellite launched into space.

That turbine, a one-eighth scale version of the turbines that would be used in the future offshore wind farm, will be floating in the Gulf of Maine next year, likely between April and August.

“We’re here at the beginning of an exciting era that could create a whole new industry in our state,” center Director Habib Dagher said Friday, standing under a 112-foot turbine blade that has been undergoing stress testing at the Offshore Wind Lab in recent months.

The turbine going into the water off Monhegan Island next year will be used to test control systems and sensors that would be used on the full-scale version.

“It basically will be able to sense the environment around it,” Dagher said.

Based on wind speed and direction, the turbine automatically turns and adjusts the angle of its blades to attain the most efficient use of the wind or avoid its full force if it grows too strong. The full-scale versions would be able to do the same thing.

A floating base for the turbine is in the works. Next year, the turbine parts will be taken to Cianbro in Brewer, where the pieces will be assembled and the floating turbine will be towed upright down the Penobscot River to its test site in the Gulf of Maine. Once in place, it will be hooked up to the power grid with an undersea cable, becoming the first grid-connected offshore turbine in the country.

The turbine design is called VolturnUS, a combination of the words volt, turn and U.S., a name that happens to be shared by Volturnus, the Roman god of the east wind.

After testing with the prototype is completed, a pair of 6-megawatt turbines will be installed by 2017 at a site called Aqua Ventus I. By 2020, that would grow to a larger-scale commercial wind farm with 80 turbines in a 4- by 8-mile space 20 miles offshore, over the horizon and neither visible nor audible from shore. By 2030, the goal is to have a full-scale wind farm of around 170 turbines operational and bringing 5 gigawatts of wind energy to Maine’s shore.

“It’s a crawl before you walk, walk before you run approach,” Dagher said.

Some offshore wind energy efforts in Europe, which has been involved in offshore wind since 1991, have struggled, resulting in lofty price tags and high energy costs. Turbines at other offshore wind farms need to have their bases driven into the seafloor, an expensive process. If a turbine needs work, it can be towed back to shore, where repairs will be less costly.

The more cost-effective floating wind farm approach should help keep electricity prices down to about 10 cents per kilowatt hour by 2020, which is competitive with other means of electricity production, Dagher said. Prior to that, the energy will be expensive by comparison.

To put the size of the turbine in perspective: The world’s largest commercial airliner, the Airbus A380 with its 260-foot wingspan, could rest on one blade of the turbine. The diameter of the blades’ rotation will be 500 feet and the distance from water level to the hub at the top of the tower will be about 300, Dagher said.

The Gulf of Maine has some of the strongest, most persistent winds on the East Coast. Every second, 600,000 pounds of wind will travel through the turbine — the equivalent of 264 Toyota Camrys driving through per second — according to Dagher.

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