 Cold water, pumped through a second heat exchanger, condenses the vapor into a liquid, which is then recycled through the system.In 1979, the Natural Energy Laboratory and several private-sector partners developed the "mini OTEC" experiment, which achieved the first successful at-sea production of net electrical power from closed-cycle OTEC.The mini OTEC vessel was moored off the Hawaiian coast and produced enough net electricity to illuminate the ship's light bulbs and run its computers and television.