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Consortium to look at costs and capacities of wave energy

SAN DIEGO ---- The California Energy Commission has awarded $120,000 to a consortium of scientists, engineers and businesses to see what it would take and what it would cost to use the motion of the ocean to produce power.

Asfaw Beyene, a professor of mechanical engineering at San Diego State University, will head the group that will look at some of the most basic questions still unanswered about harnessing the ocean's power.

BILL WECHTER / Staff Photographer

A boogie boarder rides a breaking wave off Seaside Beach in Cardiff on Saturday. A consortium of scientists, engineers and businesses has received a state grant to see what it would take and what it would cost to use the motion of the ocean to produce power.

"We don't know how much energy is out there, we don't know how much it will cost to exploit it and we don't know how it will affect the environment," Beyene said. "Those questions have to be answered to know is it worth spending the money on converting to wave power."

Among the other scientists and engineers in the consortium is Richard Seymour, a professor of oceanography at the Scripps Institute of Oceanography. Seymour has worked extensively on the effects of wave motion, including consulting on the sand projects for the city of Oceanside.

The idea of harnessing the energy in the ocean, mostly generated by the sun and the wind, is not new. Japan, Scotland, Norway, Australia, India and, most recently, Vancouver, British Columbia, are all betting on culling electricity from the ocean.

But there has been little funding for such studies in the United States, Beyene said.

In 1991, Pacific Gas & Electric Co. looked at wave energy from the north coast of California and decided that 23,000 megawatts of electricity could be culled off the Pacific Ocean there. That's enough power for 23 million homes a day, according to energy commission officials.

But plentiful, cheap electricity made the extra cost and work of developing a new energy source unappealing, Beyene said.

"There is no good research here because we tend to worry about energy only in times of crisis," he said. "Those nations pay four or more times what we do for power, so they are much more interested in alternative technologies."

One theory for obtaining electricity is based on the temperature differences between surface water, which is heated by the sun, and deep water, which stays very cold. Thermal energy conversion plants use the surface water to make steam and then pass the steam through a turbine generator to make electricity.

The first thermal energy conversion plant was built in Cuba in 1930.

Another approach to getting electricity from the ocean involves capturing the energy in waves. The energy in waves comes from the movement of the ocean and the changing heights and speed of the swells, he said.

Wave energy can be culled several different ways, according to Joe Leary, vice president of Pacific Ocean Wave Energy Research Inc., a San Diego nonprofit that promotes and shares information about wave energy. Leary is partners with Seymour and will be working with Beyene on the wave research project.

"The power is in the length and height of the wave," Leary said. "A high, quick wave doesn't give much power, where a series of long, slow moving waves has a tremendous amount."

Any surfer who has ever been caught in a wave and tossed around the bottom knows how powerful the wave feels there. But, Leary said, by the time the wave gets to the beach, most of the power is gone.

A New Jersey company, Ocean Power Technologies Inc., pitched a wave energy system to the U.S. Senate Committee on Environment and Public Works in May 2001.

Its system involves a series of anchored buoys that rise and fall with the wave. The movement "strokes" an electrical generator and makes electricity that is then shipped ashore by underwater power cable, according to the company Web site.

Leary said his for-profit company, Float Inc., has focused on the oscillating water column approach because it seems the most productive and viable.

The column fills with water as the wave rises and empties as it descends. In the process, air inside the column is compressed and heats up, creating energy the way a piston does. That energy is then harnessed and sent to shore by electrical cable.

Leary's group has proposed building a new airport on a 500-acre platform three miles off the coast of San Diego County. To do that, they would have to eliminate the waves that would rock the platform, he said. Eliminating waves is a natural result of the oscillating water tower approach.

"We would put hundreds of inverted cylinders, a whole array of oscillating water columns under the platform," he said. "You'd get your airport and a whole lot of electricity to boot."

Leary, who called his company a typical wave energy company, said there is no way of knowing how much energy could be harnessed.

"This is the first step because they are looking to see if it's feasible," he said. "The real issue is how much will it cost to build electricity and they will decide based on it is competitive by the kilowatt hour."

Sucking the energy out of waves probably will leave parts of the ocean flat, Professor Beyene said.

"Part of the feasibility study is to see what will be the impacts on fishing, surfing and beaches," he said. "But we know we are not going to put these devices on the whole ocean, so we can think about where to put them so they do little harm.

"Waves pass in large groups, so if we angle our equipment properly and avoid the areas where people go for recreation, we should be able to avoid serious problems," he added.

Contact staff writer Marty Graham at (760) 740-3517 or mgraham@nctimes.com.

3/25/02

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