The temperature differential between the tropical ocean surface and deep waters represents tremendous energy potential. Ocean thermal energy conversion (OTEC) systems represent an environmentally sound method to extract that energy resource. Included in this paper is a review of the history of OTEC, basic thermodynamic principles involved and major components of the system. The three basic types of OTEC systems are discussed, citing the various advantages and disadvantages of each. The resource extent and possible environmental impacts are examined from the U. S. perspective. After reviewing the conflicting ocean use interest involved, comparative cost calculations of energy types, and the secondary benefits of plants, projections for the future of OTEC facilities are given
