Ocean Thermal Energy Conversion (OTEC) Systems

This chapter describes the concept of generating energy and power from the thermal energy of vast oceans. The three basic types of ocean thermal energy conversion (OTEC) systems are discussed as follows: (a) closed-cycle systems, (b) open-cycle systems, and (c) hybrid systems. The basic thermodynamic cycle (Rankine Cycle) for OTEC systems is discussed including examples for power calculations using theoretical and actual values. The overall conversion efficiency of OTEC systems is quite low, but with vast ocean resources, the total potential is significantly high. The OTEC components are discussed, including temperature profiles in each system. The ideal locations for an OTEC system lie in the tropical coastal areas between the Tropic of Capricorn and the Tropic of Cancer. The primary limitation of an OTEC system is the requirement for a large-scale conveying system for ocean salt water and the durability of materials for long-term use. Numerous projects that are under way for OTEC systems are enumerated around the world. There are technical and cost limitations, and these are enumerated as well.