Saturday, March 20, 2010

Geothermal Plant

Our tour of the Salton Sea on President's Day Weekend included a visit to the Hoch Geothermal Plant, one of 10 plants scattered around the sea. The above photo shows Bill and me with our hard hats, goggles, and earplugs, three stories up next to a giant turbine.

The Salton Sea geothermal field was discovered in 1958 by some folks who dug a mile-deep well. Instead of oil or gas, they found superheated fluid--i.e., about 460 degrees. Today electricity is produced by bringing that fluid to the surface. The wells have to be lined with titanium because the fluid contains corrosive minerals. But power generation uses a closed system that's completely clean. What's escaping out of those smokestacks is pure steam.

This control room is the command center for five power plants. Altogether, the geothermal plants at the Salton Sea produce 335-340 MW of electricity per day. One MW is enough to power 750 residences. The biggest customer is Southern California Edison, followed by the County of Riverside. (Thanks to Bill for this photo.)

The resource could last another 100-200 years even if production doubled. The catch is more transmission lines would be needed--and because of their impact on the environment, it doesn't look like more transmission lines are going to be built.