Navy plans to harness
wave power in KaneoheA buoy moored at sea may generate
electricity for up to eight houses
The Navy wants to harness the power of Pacific waves off Kaneohe to produce electricity that could be cheaper than solar energy and power created by fossil fuels.
A 200,000-pound anchor now rests in 100 feet of water three-quarters-of-a-mile offshore and a subsea cable has been played out to the site.
The deployment of the anchor and cable in September was the first step in a $9.5 million Navy experiment to prove the feasibility of using wave power to light up several homes at the Marine Corps Base Hawaii at Kaneohe.
In mid-December, plans call for a 40-foot-long, 15-foot-diameter, vertically positioned subsurface buoy to be attached to ride up and down on a rigid pole extending up from the anchor, said Don Rochon, spokesman for the Pacific Division of the Naval Facilities Engineering Command which is overseeing the project.
The buoy's up-and-down movement, caused as a swell passes, mechanically creates a flow of hydraulic fluid to drive an electrical generator housed in a canister on the ocean floor, he said.
The only visible part of the device will be a brightly colored navigation mast sticking up to warn boaters to avoid coming too close.
In January, the watertight canisters containing the generator and a transformer to change the direct current electricity to alternating current, along with data recording equipment, will be fixed to the ocean bottom at the site, Rochon said.
It's expected the device will generate an average of 20 kilowatts and up to a peak of 50 kilowatts that will be plugged into the Marine base's Hawaiian Electric Co. grid, enough to serve five to eight homes.
"We hope to have an official ribbon-cutting ceremony in the spring, hopefully to coincide with the congressional recess," Rochon said.
Tentative plans call for deploying a second buoy system next year with increased efficiencies to generate up to 100 kilowatts of power, he said.
The wave power technology was developed by Ocean Power Technologies Inc. of New Jersey, which holds the $9.5 million contract from the U.S. Navy's Office of Naval Research to test it in Hawaii.
If the Hawaii test of the company's trademarked PowerBuoys is successful, the Navy hopes to use the technique and equipment at its shoreside bases around the world.
Several prototypes of the system were successfully tested off the New Jersey shore in Tuckerton since 1998.
The company said it's a technology in which bigger is better.
With a 100-megawatt system, the cost of generating electricity can be lowered to 3 to 4 cents per kilowatt hour, slightly cheaper than electricity generated from fossil fuels and much cheaper than wind or solar energy systems, it said.
