The United States' first commercial tidal energy project is expected to deliver electricity in September to consumers in Maine.

Portland, Maine, company Ocean Renewable Power Co. unveiled the first dam-less tidal generator this week for its Cobscook Bay project, off the coast of Eastland, which known for its powerful tides.

The project at first will supply electricity to 75-100 households and ultimately will power more than 1,000 homes and businesses.

Under a 20-year power purchase agreement electricity from the site will be sold to three Maine utilities, starting at 21.5 cents a kilowatt hour, nearly double the state's average electricity price of 11.21 cents a kilowatt hour, The Boston Globe reports.

In 2010, the U.S. Department of Energy awarded a $10 million grant to ORPC for the project.

Citing the upcoming launch of the device in the bay, along with the 20-year PPA, Ocean Renewable President Chris Sauer told Maine's WCSH News that "the combination of those two things will certainly attract the additional investment that we need."

In a statement this week timed with a dedication ceremony at Cobscook Bay, U.S. Energy Secretary Steven Chu said the tidal energy project "represents a critical investment to ensure America leads in this fast-growing global industry, helping to create new manufacturing, construction, and operation jobs across the country while diversifying our energy portfolio and reducing pollution."

"Developing America's vast renewable energy resources is an important part of President Obama's all-of-the-above energy strategy to create jobs and strengthen U.S. global competitiveness," Chu said.

A Energy Department tidal energy resource assessment released earlier this year indicates a potential of 250 terawatt hours of electricity could be generated annually from the country's tidal currents, with "major opportunity" hotspots for developments along the East Coast, as well as in Alaska and Hawaii.

Ocean Renewable's cross-flow "TidGen" device measures 95 feet by 50 feet and will stand 31 feet tall on its seabed foundation.

After the unit is operational, the Department of Energy requires a visual inspection every 12 weeks for the first year, the Bangor Daily News reports. That entails the use of a large, barge-mounted crane to lift the 90,000-pound turbine out of the bay, then reattaching it to its seabed foundation after the inspection.

U.S. Sen. Susan Collins, R-Maine, said the state is well-positioned to lead the country in tidal energy development, noting that the project "is one example of the type of actions we need on a national scale to stabilize energy, prevent energy shortages, and achieve national energy independence."