An Ocean Thermal Energy Conversion (OTEC) system having a turbine with an upstream side and a downstream side. Warm water under a partial vacuum is converted into a vapor, the vapor being supplied to the upstream side of the turbine at a pressure controlled by the temperature of the warm water. A condenser is situated on the down-stream side of the turbine to cause the vapor, after passing through the turbine, to undergo a phase change back to a liquid, which can be used as potable water. The condenser is coupled to a source of a cooling liquid, and the pressure of the vapor on the downstream side of the turbine is determined by the temperature of the cooling liquid. A flexible floating solar collector supplies the warm liquid to the upstream side at a temperature higher than normal ambient temperature.