Explains how air, water, earth, and fire are transformed into clean, reliable sources of heat, electricity, and even automobile fuel. Looks at a solar roof implementation by FedEx at a regional sort facility in Oakland, Calif., a wind power project in central New York using fewer, larger turbines, and the widespread use of geothermal energy in Iceland. Visits Lovecraft Biofuels in Los Angeles, an auto repair shop that converts diesel car and truck engines to run on one hundred percent vegetable oil. Examines the potential use of hydropower from ocean tides, such as tidal barrages, as well as a tidal stream (or flow) power project off the shore of England that uses propeller-like turbines to capture the kinetic power of underwater currents.