Cities Eye Ocean Waves for Power Supplies

SAN FRANCISCO / NEW YORK Since ancient times poets have revered the power of the seas. Now energy companies and coastal cities like New York and San Francisco are aiming to tap ocean waves and tidal currents as abundant sources of electricity.

Whether captured by big buoys bobbing on sea swells, or by submerged turbines spinning with the ebb and flow of the tides, the energy potential of moving water, or marine power, is beginning to turn heads in the energy world.

"I'm pretty bullish on the technology," said Robert Thresher, a wind power researcher at the Department of Energy's National Renewable Energy Laboratory.

Thresher said water power has several advantages over wind power, including having a lower profile. One day marine power could catch on like wind power, currently the fastest growing alternative energy, he said.

"It doesn't have the visibility of a wind turbine device," he said. Some critics, famously Massachusetts Democratic Sen. Ted Kennedy, have fought offshore wind farms because they say a forest of tall turbines spoils views of the horizon.

Another advantage, Thresher said, is that water currents are more energy-dense than wind currents - about 1,000 times more.

"My wind power brethren say their turbines generate more power when it's humid," said Trey Taylor, president of Washington-based Verdant Power, which makes underwater turbines. "I like to say, 'You can't get any more humid than water.'"

Marine power is in its infancy. But an experimental wave project run last summer by Ocean Power Delivery Ltd in the Scottish Orkneys successfully provided power to 500 homes through Scottish Power. Marine power research has received millions of dollars worth of government subsidies in Scotland, but the United States currently has no federal program.

Still, the potential is high for U.S. waters, even at many of the nation's thousands of dams and rivers. "Just below the Niagara Falls is a fantastic source of energy," Taylor said.

The technology is so young that fish protectors Trout Unlimited have not formed an opinion on wave power. But marine conservation group Surfrider Foundation is "guardedly optimistic" about a system of buoys planned by New Jersey-based Ocean Power Technologies, said spokesman Matt McClain.

Reuters