Ocean power surges forward

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."

Funding is a problem. As with most renewable power, financing for ocean power has been becalmed by the nation's financial crisis. Some 17 Wall Street finance companies that had funded renewables, including ocean power, are now down to about seven, says John Miller, director of the Marine Renewable Energy Center at the University of Massachusetts at Dartmouth.

Even so, entrepreneurs like Sauer aren't close to giving up – and even believe that the funding tide may have turned. Private equity and the state of Maine provided funding at a critical time, he says.

"It's really been a struggle, particularly since mid-September when Bear Sterns went down," Sauers says. "We worked without pay for a while, but we made it through."

Venture capitalists are not involved in ocean energy right now, he admits. Yet he does get his phone calls returned. "They're not writing checks yet, but they're talking more," he says.

When they do start writing checks, it may be to propel devices such as the Pelamis and the PowerBuoy. Makers of those devices, and more than a dozen wave-power companies worldwide, will soon vie to be among five businesses selected to send their machines to the ocean off Humboldt.

One of the major challenges they will face is "survivability" in the face of towering winter waves. By that measure, one of the more successful generators – success defined by time at sea without breaking or sinking – is the Pelamis, a series of red metal cylinders connected by hinges and hydraulic pistons.

Looking a bit like a red bullet train, several of the units were until recently floating on the undulating sea surface off the coast of Portugal. The Pelamis coverts waves to electric power as hydraulic cylinders connecting its floating cylinders expand and contract thereby squeezing fluid through a power unit that extracts energy.

An evaluation of a Pelamis unit installed off the coast of Massachusetts a few years ago found that for $273 million, a wave farm with 206 of the devices could produce energy at a cost of about 13.4 cents a kilowatt hours. Such costs would drop sharply and be competitive with onshore wind power if the industry settled on a technology and mass-produced it.

"Even with worst-case assumptions, the economics of wave power compares favorably to wind power," the 2004 study conducted for EPRI found.

One US-based contestant for a WaveConnect slot is likely to be the PowerBuoy, a 135-five-foot-long steel cylinder made by Ocean Power Technology (OPT) of Pennington, N.J. Inside the cylinder that is suspended by a float, a pistonlike structure moves up and down with the bobbing of the waves. That drives a generator, sending up to 150 kilowatts of power to a cable on the ocean bottom. A dozen or more buoys tethered to the ocean floor make a power plant.

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