This paper describes the performance analysis of an ocean thermal energy conversion (OTEC) plant in the Oki-no-Erabu Island where is one of suitable sites proposed for OTEC. On June 8, 1990, June 8, 1991 and August 25,1991, investigations of marine meteorology, such as temperature of seawater, velocity and direction of tide and submarine cross section, was carried out with a research ship of the Shimonoseki University of Fisheries. These data are compared with marine meteorology data obtained from the Japan Oceanographic Data Center(JODC). A conceptual design for a 10 MW onland type I -H OTEC plant is conducted with these data. The steepest descent method was used to obtain the optimum system. The objective function of the system is defined as the total heat transfer area of heat exchangers per net power output.
The ocean thermal energy conversion (OTEC) is a system converting heat energy into electricity by using the temperature difference between the warm seawater at the surface and cold seawater of the depths. Since in the OTEC plants, the available temperature difference (15~ 26°C) is small, the Rankie cycle efficiency is only 3 ~ 5% (Uehara and Ikegami, 1990). Therefore, it is important to consider the total system of the OTEC plant. Panchal et al. (1987) carried out the system analysis for a hybrid cycle OTEC plant. An analysis of the total system of an integrated hybrid OTEC were reported by Uehara et al. (1990). For considering the total system of the OTEC, the choice of location is very important. The location depends on conditions of the temperature and velocity of the seawater, the geographic features in the sea, and the consumption of the electric power and drinking water.