Renewables are often seen as "new." In fact, they are the original energies. Wind, water, biomass and the earth's heat have been used for thousands of years. Being able to harness those resources on a mass-scale is what's new.

Half a century ago, just north of San Francisco, construction began on The Geysers, the nation's first commercial geothermal site. Now an extensive complex of geothermal energy production, the Geysers has come a long way from its beginnings as a single 11-megawatt power plant.