March 10, 2009, 2:32 PM — NASA scientists say they've found a way to turn the power of the ocean's tides into clean, renewable electric energy.
NASA is working to use changes in ocean temperature to create a high-pressure fluid that can be used to generate power. The new technology is an offshoot of work NASA has been doing to power underwater robotic vehicles, according to the space agency.
"This type of hydraulic energy transfer system is potentially applicable to many types of hydrokinetic energy from rivers, ocean waves, tides and currents," said Yi Chao, a scientist with NASA's Jet Propulsion Laboratory, in a statement. Scientists can use computer models of winds, river flows, ocean currents and tides to calculate an area's potential for energy production, he added.
With increasing concern about global warming and growing efforts to find clean, renewable energies, researchers around the globe have been working to find new power sources.
Earlier this month, a group of researchers at MIT developed an out-of-the-ordinary solar powered race car that isn't dependent at all on gasoline. The car, dubbed Eleanor, can maintain a cruising speed of 55 mph and run all day -- if the sun is shining, according to MIT.
The car is just the latest MIT solar research effort touted by the Cambridge, Mass. university.
Last December, MIT researchers announced they were working to boost the output and efficiency of solar cells to lower the cost of solar power by drastically cutting the need for very pricey, high-quality silicon.
And last August, MIT reported that a team of researchers there had made an energy storage breakthrough that could transform solar power from an alternative source of energy to a mainstream option. And a month earlier, MIT announced that its researchers had created a new way to harness the sun's energy by turning windows of large buildings into solar panels.
Chao and Jack Jones, an engineer at the Jet Propulsion Laboratory, said that NASA engineers have designed a system that uses water temperature and motion to generate a high-pressure liquid rather than electricity. That liquid, according to NASA, is then transported to shore and used to produce electricity on land.
"The trick was to find a special substance known as a phase change material that changes from a solid to a liquid as the temperature in the environment changes from cold to warm," Chao says. "When the material melts, it expands, compressing a central tube in which another liquid is stored. This liquid, now under high pressure, is used to generate electricity."
California Institute of Technology, which operates JPL for NASA, holds the patent on the new technology.