Officials of Seattle-based AquaEnergy Group Ltd., an alternative energy company, say the 1-MW system is slated to produce power by mid-2004 from a site 3.2 miles off Makah Bay in Northwest Washington. It would be the world's first full-scale, installed commercial system. Such a system would power about 150 houses year-round in the mild climate of the Pacific Northwest.
(Photo courtesy of
The AquaEnergy system is not tidal, but wave-driven. An initial pilot installation will consist of four buoys, whose up-and-down motion caused by waves of up to 50 ft will create water pressure of roughly 200 psi to drive underwater pistons, which in turn will operate a turbine that feeds a generator. The offshore system has a working end that extends about 60 ft beneath the surface and will be connected by cable running along the ocean floor to a power-conditioning station on shore at Hobuck Beach.
Wave resonance is controlled by an electronic package aboard the 30-ft-tall buoys, 15 ft of which are submerged, says Alla Weinstein, president and CEO of AquaEnergy. In rough winter sea, ballast may be adjusted electronically via satellite by onshore computers, he adds. Power will be fed into the Clallam County Public Utility District grid, says Weinstein.
AquaEnergy is handling the Makah Bay installation in a joint effort with the Northwest Energy Innovation Center, Bonneville Power Administration, Energy Northwest, Washington State University and Batelle Memorial Institute. The consortium is seeking a $3-million grant from the U.S. Dept. of Energy for the project.
"Makah Bay offers consistently powerful waves close to shore," says Weinstein. "The scenario offers a reliable source of energy and a short path of transmission to a shore collection point, both vital ingredients for siting economically feasible ocean wave power stations."
|BUOYANT POWER The wave-driven system uses buoys to create pressure and power tribunes.|
AquaEnergy is talking with potential developers in New Zealand, Australia, South Africa and Spain, and is seeking a European Union grant for a 20-Mw installation at one of four sites off the Portuguese coast, says Ken Kukes, AquaEnergy executive vice president. A wave system of the scale planned for Portugal would generate power at a wholesale cost of 4 to 4.5 cents per kwh, equivalent to wind, Kukes says. The cost is "less if you build a larger plant," he adds.
The Scottish firm Ocean Power Delivery Ltd., Edinburgh, is one of more than a dozen firms worldwide joining AquaEnergy in plans for similar offshore systems that make up the growing "green" power revolution. Ocean Power recently announced plans for a full-scale test of a similar-scale tidal system (ENR 4/7 p. 17).