Water heating, space heating, and space cooling systems with and without solar assistance and with and without off-peak thermal storage are analyzed for Philadelphia, PA; Daytona Beach, FL; and San Diego, CA. These locations cover different climates and are served by electric utilities having different generation and growth patterns. The utility's costs of service and the homeowner's capital investment costs are determined in order to obtain total annual costs. Comparisons permit conclusions as to where and when the novel systems will be economical compared to conventional systems, and how off-peak thermal storage affects these results.