WATER - Cool NREL maps show the huge geothermal power potential of the U.S.

Geothermal is a stable & plentiful source of clean energy available all around the world, including in the United States (especially in the West). But that industry is still in its infancy and very little of that resource's potential is being tapped.

http://www.treehugger.com/slideshows/renewable-energy/series-map-show-