This timely study deals with the heating and cooling of buildings using innovative systems that can reduce fossil fuel and electric energy requirements by as much as 80 percent. Emphasis is placed on thermal storage, utility rate structures, peak load problems, and cogeneration of heat and power in small-scale applications. The first several chapters treat promises and problems of solar energy use for efficient comfort conditioning. Other contributions deal with the social implications of future energy efficiency requirements with a focus on the community.