Tidal Power: Generating Megawatts Like Clockwork  

The New York Times has a look at the past and future of tidal power in Maine - Generating Megawatts Like Clockwork.

WHEN Christopher R. Sauer stands before the swirling waters of the Western Passage and describes his company’s alternative energy vision, he doesn’t see an army of wind turbines or banks of solar cells.

In fact, Mr. Sauer sees nothing at all that could block his view of Canada, just across the channel. For if his plans come to fruition, an array of turbines will be operating out of sight, deep under the water, cranking out power to a substation on shore.

His company, Ocean Renewable Power, is one of a number of start-ups trying to develop tidal energy — water-powered turbines that spin in the current as the tides come and go, turning generators to make electricity that is clean and, they hope, reasonably priced.

“We’re not going to beat out the old coal plants in the Ohio Valley,” said Mr. Sauer, who has decades of experience developing co-generation plants and other power projects. “But we will be competitive with any new power source, including fossil fuels.”

That’s an ambitious goal, but Mr. Sauer, the company’s president and chief executive, has at least gravity and the earth’s rotational energy on his side.

Tides come and go twice a day everywhere around the globe. In places like Eastport — a former sardine capital at the mouth of the Bay of Fundy that is surrounded by deep channels like the Western Passage — tidal power makes the most sense, at least for the moment.

Here the tides are very high and the current strong, reaching about 6 knots, or 7 miles per hour, at peak flows four times a day. “We’ve got the best tidal current on the East Coast,” Mr. Sauer said.

Tidal power is not a new idea. A few tidal generating stations are already operating around the world, including one in France that is more than four decades old. But they represent an older approach, one that employs barrages, or dams, to hold back the high tide. The water is then released through turbines, like a conventional hydroelectric plant, when the tide goes out.

Eastport itself was the site of an elaborate and enormous barrage project, proposed in the 1930s during the administration of Franklin D. Roosevelt, who knew of the great tides here, having spent many summers on Campobello Island nearby. The project, the East Coast’s answer to Hoover Dam, was abandoned after a year.