book. Design aspects of, and results from large experimental and demonstration plants are described by individuals who were directly involved in the design and testing of many of these plants. Consideration of the viability and future economics of large-scale solar power generation provides an outlook on the energy contributions which can be expected from an optional future supply of abundant and renewable energy, having little impact on the environment. This provides the rationale for the continued commitment to the development of solar power technologies by researchers, engineers, and industry. The eventual depletion of, or future political attacks on our energy supply will have less serious impact once this renewable option is in place.