There are three important problems facing the world: deple- tion of fossil fUels, demand for more energy, and the pollution of our environment. The world contains limited amounts of fossil fuels. They are being depleted, at an ever-growing rate. Peoples of the world are demanding more and more energy. This is due to the desires of peoples to improve their standard of living--and the standard of living is directly proportional to the energy con- sumed. In addition, the world is demanding a cleaner environment to live in. Many of us, scientists and engineers, believe that replacing fossil fuels...