Harnessing the awesome power of the ocean waves

[Tank]

Harnessing the awesome power of the ocean waves

MBARI engineer Andy Hamilton looks out his office window in Moss Landing and points at the waves crashing on the beach below. "Pretty impressive, aren't they? You'd think there'd be a way to make use of all that energy." Since 2009, Hamilton has led a team of engineers trying to do just that. Their goal is not to replace the hulking power plant that overlooks Moss Landing Harbor, but to provide a more generous supply of electricity for oceanographic instruments in Monterey Bay.

Hamilton's "power buoy" project is funded by the Defense Advanced Research Projects Agency (DARPA), which sponsors research into revolutionary new technologies that might one day be used by the U.S. military. The project started with a three-month grant to assess the availability of wave power around the world, and to assess DARPA's previous attempts to generating electrical power from the waves.

Hamilton's initial research and calculations showed that DARPA's previous efforts had been too timid—their small prototype buoys were never able to take advantage of the full energy of the waves. So Hamilton proposed to "go big" (but not as big as commercial wave-power projects).

He spent another nine months using computer models to test different buoy designs under a variety of simulated wave conditions. In the end, he came up with a buoy that was 2.5 meters (8 feet) across. Hanging in the water below this buoy is a massive metal plate 3 meters (10 feet) wide and 5.5 meters (18 feet) long.

Because most wave motion occurs at the sea surface, the buoy rises and falls with the waves, but the plate, 30 meters (100 feet) down, remains relatively stationary. Between the surface buoy and the metal plate is a large hydraulic cylinder with a piston inside. As the buoy rises and falls, it pushes and pulls on this piston. This forces hydraulic fluid through a hydraulic motor, which in turn runs an electrical generator...

It'll be interesting to see what effect 100s of these devices would have on the ecology of the area behind them. The energy extracted would have gone on to impinge on the shoreline and the organisms on the shoreline would be those adapted to the original conditions.