A solar cell floats over a body of saline water. A submerged fresh water collection system underlies the cell. A partial vacuum is created in the solar cell for drawing water vapor from the cell to the collection system. Water vapor is condensed in a condenser disposed between the cell and the collection system. Heat generated by the condensation of water vapor is utilized to heat the salt water, which rises upwardly to replace the salt water vaporized in the cell. The fresh water from the fresh water collection system is routed under the cell such that it becomes thermally enriched. The thermally enriched fresh water is provided to a power generator to improve efficiency.