Ocean Thermal Project In Japan

Totally 3 sets of on-shore ocean temperature differential power station has been built in Japan. At June, 1980, one set of 100kW closed circulation temperature differential power station was started to built in Nauru financed by Tokyo Electric and the government in an amount of 1.1 billion Japan Yuan, which was put into test run at Oct., 1981 and was put into operation for a year. The power station was employed R-22 as the working medium, with the temperature in the outlet of cool water of 7.8°C, with the temperature in the outlet of heat water of 29.8°C, with the diameter of cool water pipe of 0.7m, length of 950m. The average generation efficiency was 100.5kW. Deducting the system consumption of operation needs, the average net output was 14.9kW, which was connected to the local utility grid.

At August 1981, a 50kW pilot power station was constructed in Japan, which started its test, run at Sep., 1982 and has been operated until August 1994. The total investment was 1 billion Japan Yuan supported half by enterprise and half by the government. This power station belongs to hybrid type, with the working medium of ammonia, which was employed plate type heat exchanger. The heat resources of the power station was not directly taken from the warm seawater in the surface of the ocean, but the surface seawater which had been reheated by the residue of generator of diesel engine in the island. The temperature of heat resources can hit 40.5°C; while the temperature in the outlet of cool water was 12°C; therefore the temperature differential can reach 28.5°C. The diameter of cool water pipe was 0.6m; the length was 2300m. The average net output can reach 32kW. Furthermore, another experiment device with the capacity of 75kW was built in 1985, which can obtain 35kW net output.