A sign in front of a drilling derrick as part of the energy research project Deep Heat Mining is seen at the Industriellen Werke Basel in Basel, Switzerland, Jan. 16, 2007. Scientists say geothermal energy is clean, quiet and virtually inexhaustible, and estimate it could provide 250,000 times more energy than the world currently consumes each year, with nearly zero impact on the climate or the environment. Credit: AP Photo/Keystone, Georgios Kefalas