More than 50 companies worldwide and 17 US-based companies are now developing ocean power prototypes, an EPRI survey shows. As of last fall, FERC tallied 34 tidal-power and nine wave-power permits with another 20 tidal-current, four wave-energy, and three ocean-current applications pending.
Some of those permits are held by Christopher Sauer's company, Ocean Renewable Power of Portland, Maine, which expects to deploy an underwater tidal-current generator in a channel near Eastport, Maine, later this year.
After testing a prototype since December 2007, Mr. Sauer is now ready to deploy a far more powerful series of turbines using "foils" – not unlike an airplane propeller – to efficiently convert water current that's around six knots into as much as 100,000 watts of power. To do that requires a series of "stacked" turbines totaling 52 feet wide by 14 feet high.
"This is definitely not a tinkertoy," Sauer says.
Tidal energy, as demonstrated by Verdant Power's efforts in New York City's East River, could one day provide the US with 3,000 megawatts of power, EPRI says. Yet a limited number of appropriate sites with fast current means that wave- and offshore-wind power have the largest potential.
"Wave-power technology is still very much in emerging pre-commercial stage," says Roger Bedard, ocean technology leader for EPRI. "But what we're seeing with the PG&E WaveConnect is an important project that could have a significant impact."