Ocean power could be limitless

Who doesn't love a day at the beach? Nobody I know.

And now, from The New Scientist, comes an article that gives beach lovers yet another reason to love the sea we frolic in: Ocean Thermal Energy Conversion (OTEC), a clean, renewable energy source that has the potential to us from dependence on oil.

Here's how OTEC works (in addition to this explanation they have a nice graphic if you click to the second image on the article):

  • First, warm surface water heats a fluid with a low boiling point, such as ammonia or a mixture of ammonia and water. When this "working fluid" boils, the resulting gas creates enough pressure to drive a turbine that generates power.
  • The gas is then cooled by passing it through cold water pumped up from the ocean depths via massive fiberglass tubes, perhaps 1000 meters long and 27 meters in diameter, that suck up cold water at a rate of 1000 tons per second.
  • While the gas condenses back into a liquid that can be used again, the water is returned to the deep ocean.

"It's just like a conventional power plant where you burn a fuel like coal to create steam," Robert Cohen tells the New Scientist. Cohen headed the U.S. federal ocean thermal energy program in the early 1970s - you know, back when we had our first major energy crisis.

Wish we'd paid better attention to OTEC back then. Maybe we wouldn't be in such dire straits today.

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