Finding and developing practical ways to provide the energy needed for modern technological societies on a sustainable basis without disrupting the environment is the most important problem confronting the coming generation of engineers and scientists. Regardless of which solutions ultimately emerge, it is certain that all of the topics discussed in this book will play important roles. Topics include wind energy, earth-based solar thermal concentrators and photovoltaic solar cells, solar electric stations in space that beam microwave energy to earth-based receiving stations, hydroelectric energy, biomass energy, geothermal energy, gulf stream, wave, and tidal energy, clean coal, nuclear fission reactors, nuclear fusion, hydrogen from water, electric vehicles, more efficient power grids, mass transportation, hydrogen-powered fuel-cell vehicles, efficient lighting, rail systems, better building design, and better intelligence in energy consumption.