Review of mini-OTEC performance

This paper describes some of the results from the first at-sea Ocean Thermal Energy Conversion (OTEC) powerplant. The powerplant was mounted on a barge located approximately 1.5 miles off Keahole Point on the Kona Coast of Hawaii. Ammonia was employed as the working fluid in a closed-cycle (Rankine) powerplant which produced approximately 50 kWe of gross electrical power for an average seawater temperature difference of 38 F. Parasitic pumping power requirements for seawater and ammonia resulted in a net electrical power of approximately 15 kWe. Cold seawater was drawn from a depth of approximately 2200 ft through a 2-ft-diameter polyethylene pipe which formed a part of the single-point tension leg mooring system. The first net, closed-cycle, at-sea OTEC power was produced on 2 August 1979; plant operation concluded on 15 November 1979.