The oil embargo of the early 1970's created a great boom of development activity around alternative energy technologies. It was during that time that great research occurred, largely funded with Federal dollars, in the area of solar and wind power. But as the embargo ended and oil prices stabilized, Federal funding evaporated and most of the impetus for further development ended. And alternative energy development slowed considerably.
There's tremendous work being done now in this arena. I've already written a bunch about deriving oil from single cell organisms, wind and solar power, and the development of wave power technologies.
I've
got another one. Ocean Thermal Energy Conversion (OTEC) is a "clean,
renewable energy source that has the potential to free many economies
from their dependence on oil."
From an article in New Scientist:
"This
has the potential to become the biggest source of renewable energy in
the world," says Robert Cohen, who headed the US federal ocean thermal
energy programme in the early 1970s.
The technology takes advantage of the large difference in water temperature at the surface of the ocean vs. the water at greater depths. The warm surface water heats, and boils, a fluid with a low boiling point (the article notes ammonia or ammonia mixtures are often used). The pressure generated drives turbines that generate power. The gas is cooled by passing it through cold water brought up from the ocean depths. The water is transferred via very large and very long fiberglass pipes.
In September, the U.S. Department of Energy awarded a grant to Lockheed Martin to develop a new generation of the fiberglass pipes. Lockheed Martin and Makai Ocean Engineering are collaborating on building a small (10 to 20 megawatt) plant in Hawaii and have it operational in 4 to 6 years. The power plant would feed electricity to the island via submarine power transfer cables.
Another plant, scheduled for completion in 2011, will provide electricity to a U.S. military base on the island of Diego Garcia in the Indian Ocean.
"I think OTEC has the potential to develop sufficient power output much quicker than wave buoys or tidal power would," says Bill Tayler, director of the US navy's Shore Energy Office. "It would take a lot of buoys to produce 8 to 10 MW of power. We're looking at them all but have our hopes on OTEC."
There are lots of issues still needing to be resolved - the tubes are difficult to place, attaching floating platforms to submarine power lines is difficult and the heat exchangers need to be designed so as to keep algae and other marine organisms from growing.
The recent EPA panel ruling requiring a standard carbon dioxide emission limit from power plants will no longer make coal the de facto power plant technology and allow alternative energy technologies to compete on a level playing field. That a giant like Lockheed Martin is interested in developing OTEC is a sign the technology may one day compete successfully in the energy arena.
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