Power From the Restless Sea Stirs the Imagination
(NY TIMES)--For years, technological visionaries have painted a seductive vision of
using ocean tides and waves to produce power. They foresee large
installations off the coast and in tidal estuaries that could provide
as much as 10 percent of the nation’s electricity.
The Scottish company Pelamis Wave Power plans to turn on a small wave-energy farm — the world’s first — off the coast of Portugal by year’s end. Finavera Renewables, a Canadian company that recently salvaged its sunken, $2.5 million Oregon wave-power machine, has signed an agreement with Pacific Gas & Electric to produce power off the California coast by 2012. And in the East River, just off Manhattan, two newly placed turbines with tougher blades and rotors are feeding electricity into a grocery store and parking garage on Roosevelt Island.
Roughly 100 small companies around the world are working on converting the sea’s power to electricity. Many operate in Europe, where governments have pumped money into the industry. Companies and governments alike are betting that over time, costs will come down. Right now, however, little electricity is being generated from the ocean except at scattered test sites around the world.
Ocean power has more potential than wind power because water is about 850 times denser than air, and therefore packs far more energy. The ocean’s waves, tides and currents are also more predictable than the wind.
The drawback is that seawater can batter and corrode machinery, and costly undersea cables may be needed to bring the power to shore. And the machines are expensive to build: Pelamis has had to raise the equivalent of $77 million.
