Israeli firm uses giant buoy for wave energy

www.forexyard.com
December 22, 2009

HAIFA, Israel, Dec 21 (Reuters) - Harnessing the energy of a giant buoy locked underwater may be the key to generating electricity efficiently from waves, an Israeli company says. While there are around 100 companies around the world working on marine energy, including wave and tidal power, only a handful have installed their devices at sea. Others are running tests in tanks or on computers [nLS254204]. Three-year-old firm Seanergy threw its hat in the ring this month with its first installation - - a 20-metre (66-ft)-high metal column with an internal water reservoir that holds a four-metre (13-ft)-wide buoy - - in the port of Haifa in northern Israel.

Much like how a ball held underwater rises to the surface when released, the buoy, locked in place by hydraulics until a wave comes to fill the reservoir, shoots up with 20 tonnes of force - - enough to power a generator or desalinate seawater. "Currently, we need about four months to manufacture a cluster of five buoys. But eventually, we see them in farms and clusters along the coast in every part of the world," said Seanergy founder Shlomo Gilboa.

Ocean power is the smallest sector in environmentally-friendly renewable energy. The British renewable energy association BWEA said marine technologies are in the early stages of development and are about 10 years behind wind technologies. "The costs associated with these technologies are currently significantly greater than those of wind generation, although they should be expected to fall rapidly through a 'learning curve' effect once large scale deployment begins," the group said. Depending on the waves, Seanergy's buoy can rise and fall six to ten times every minute, each time shooting a stream of water at more than 70 atmospheres of pressure.

That is powerful enough for the system in Haifa, which out of water looks like an elevator shaft, to desalinate seawater through reverse-osmosis. It dumps the brine water back to sea. Each column costs about $125,000, Gilboa said, and with four metre-high waves, a cluster of five can generate about one MW of electricity, or can desalinate up to a 850,000 cubic metres (225 million gallons) of fresh water annually. The system is more efficient than any other wave energy systems on the market today, Gilboa said. The port of Haifa plans on using Seanergy's system to power its cranes and lighting in the future, said the port's vice-president of engineering and development, Zohar Rubin.