A new power-producing technology, the first of its kind in North America, is up and running off the coast of Maine at the Canadian border. Operating since September, the nation’s first underwater generator has been delivering commercially produced tidal power to the Bangor Hydro Electric Co., the area’s electrical company. A Rhode Island company has played an important role in its fabrication and is under contract to make two more units.

Hall Spars & Rigging of Bristol is known for manufacturing world-class, seamless sailing components, including masts. In this case, however, the company fashioned the turbines – the spinning blades – for the generator.

The Ocean Renewable Power Co. of Portland, Maine, built and installed the unit in Cobscook Bay at a cost of $15 million. Company spokeswoman Susy Kist said the Bristol firm’s contribution was crucial to the generator’s success. “The attraction of Hall Spars is that they are well-versed in all composite-material manufacturing, and that is what is required for our underwater turbines,” she said.

The entire unit consists of a generator, the turbines, a chassis and a bottom support frame that mounts the unit to the ocean floor at a depth less than 100 feet. ORPC began transmission to the grid on Sept. 13 and a power-purchase agreement with the utility is being finalized. “It’s our very first unit and our first commercial project,” she said.

The rectangular turbine resembles a 100-foot-long and 20-foot-high paddle wheel and weighs 80,000 pounds. When submerged in a 6-knot tidal current like Cobscook Bay, the unit can generate 150 kilowatts, or enough to power a modest 25 to 30 homes. Two more generators, each with turbine blades fabricated by Hall Spars, are scheduled to be installed at Cobscook Bay in 2013.