US scientists trying to produce green power

Although ocean wave technology still has a long way to go, U.S. scientists are now seeking ways to make ocean wave energy the nation's newest source of green power, local media reported on Sunday. U.S. aerospace engineers are using Texas A&M University's wave tank to test the idea of applying the physics of wind turbines to the sea as they believe that if air can produce affordable electricity, so can ocean water, according to reports posted on the website of local newspaper The Houston Chronicle. Stefan Siegel, who led the testing at the university, said that ocean wave energy is decades behind wind, but with all the resource in the ocean, it's much more attractive. "The wind doesn't always blow. The sun doesn't always shine. But ocean waves, they are always there," said Siegel, whose Colorado-based startup Atargis Energy Corp. developed a device using components similar to airplane wings or wind turbine blades. According to the reports, incoming waves rotate the two wings around a central axis, and the movement activates generators connected to the device, transforming the mechanical energy into electricity. The prototype, about one-tenth the size of a full-scale device, produced 370 watts during testing at the university, and with design improvements, a full-scale version will churn out 5 megawatts in the ocean, enough to power 3,000 to 4,000 homes in the country. The rotating blades now can capture about 95 percent of a wave's energy, and the device operates just below the water's surface, partially shielding it from violent storms, the reports said. The wave tank, one of the world's oldest and largest, tests offshore oil and gas platforms. The tank, which opened in 1991 but did not get its first renewable ocean energy trial until 2003, is about half the size of a football field and simulates various ocean conditions. Based on the results of the testing, the Atargis team plans to make design improvements in a larger model, and hopes to test in the open ocean by 2014, the reports said. From:Xinhua