The power of the sun is so great that, if we could harness it fully, the sunlight beamed on the earth for 1 hour could meet world’s energy demands for an entire year!
The Romans were the first to use geothermal energy to heat their homes, with warm air moving through the walls and under the floors.
In 1990 the Sunseeker I, a solar powered airplane, flew across America in stages using no fossil fuel at all!