Abstract: A clathrate freeze desalination system and method in which a clathrate forming agent is injected through a submerged pipeline to a predetermined ocean depth at which the surrounding ocean temperature is less than the clathrate forming temperature. The agent combines with the salt water to form a slurry of clathrate ice crystals and brine. The pipeline is concentric and coaxial with a surrounding outer pipeline in which the slurry is formed. The slurry is pumped back to the surface through the outer pipeline and the ice crystals are washed to remove brine. The washed crystals are then melted, and the resultant water is separated from the clathrate forming agent, which may be discarded or recycled for re-injection through the inner pipeline. The melting of the clathrate ice as well as the cold water and air circulating in the desalination plant can be utilized as a source of air conditioning for local buildings and facilities.