How do OTEC power plants operate?

Explanation

Ocean-thermal-enerey conversion [OTEC) Power plants harness energy due to ditference in temperature at sea surface and at depths of up to 2000 metres or so. In one form of OTEC, the warm surface water is used to boil a low-boilling liquid like ammonia or a chlorofluorocarbon. The vapours of the liquid are sent to move the turbines of a generator. The cold water from the depths are used to condense the vapours escaping from turbines. To use this plant a difference of `20^(@)` C or more is required between the temperature of water surfaces, shallow and deep.