Buoy System Harnesses Wave Energy

June 29 -- One future solution to the global energy crunch could be as old as the oceans.

Later this summer, a New Jersey company will launch a series of buoys in the Pacific Ocean more than a mile off the coast of Melbourne, Australia, to harness the power of the ocean's relentless waves.

The system is expected to generate up to 10 megawatts of electricity — enough to power about 10,000 homes — for the Melbourne-Sydney power grid. And the buoy system should generate the power far more cleanly than conventional plants that burn coal or gas.

"The ocean is a very forceful environment," says George W. Taylor, president of Ocean Power Technologies. "The energy is very concentrated."

Strung by Buoys, Run by Chips

The buoys are submerged more than a meter below the water's surface. Inside, a cylinder that moves around a piston-like structure as the buoy bobs with the rise and fall of the waves. That movement drives a generator on the ocean floor, producing electricity, which is sent to the shore along an underwater cable.

Computer chips constantly monitor the system's performance, disconnecting the system when unusually large waves threaten to disrupt it and reconnecting it when the waves return to normal.

The Australia project could have up to 20 buoys, each about 4.5 meters (or nearly 15 feet) in diameter and capable of generating 50 kilowatts of electricity. Ocean Power Technologies also has a contract with the U.S. Navy to install a 1-megawatt system for a base in Hawaii.

The company developed the technology with a grant from the Navy, first testing it for 11 months in an offshore station that recharged two-man research mini-subs in the ocean off Atlantic City, N.J. That system survived several major storms — even Hurricane Bonnie, which had waves as high as 30 feet.

Taylor envisions systems as big as 100 kilowatts powering small coastline communities or offshore oil rigs. Eventually, larger plants could plug into regional power grids, he says.