OTEC produces electricity from the natural thermal gradient of the ocean, using the heat stored in warm surface water to create steam to drive a turbine, while pumping cold, deep water to the surface to recondense the steam. In closed-cycle OTEC, warm seawater heats a working fluid with a low boiling point, such as ammonia, and the ammonia vapor turns a turbine, which drives a generator. The vapor is then Condensed by the cold water and cycled back through the system. In an open-cycle plant, warm seawater from the surface is pumped into a vacuum chamber where it is flash evaporated, and the resulting steam drives the turbine. Cold seawater is then brought to the surface and used to condense the steam into water, which is returned to the environment. Hybrid plants, combining benefits of the two systems, would use closed-cycle generation combined with a second-stage flash evaporator to desalinate water [2]. OTEC plants can either be built onshore or on offshore floating platforms. Floating platforms could be larger and do not require the use of valuable coastal land, but incur the added expense and impact of transporting energy to the shore. Energy can be transported via seafloor cable, a well-developed but costly technology that impacts the environment by disrupting seafloor communities, or stored in the form of chemical energy as hydrogen, ammonia or methanol. Plants hips used to produce hydrogen, ammonia or methanol would‘‘graze’’ the ocean slowly, store products for about a month, then transfer products to a tanker that would take the products to shore [3]. It is possible to derive ancillary benefits from both the warm and cold water cycled through OTEC plants. In an open-cycle plant, the warm water, after being vaporized, can be recondensed while keeping separated from the cold seawater, leaving behind the salt and providing a source of desalinated water fresh enough for municipal or agricultural use. The cold-water effluent can be applied to mariculture (the cultivation of marine organisms such as algae, fish, and shellfish), air conditioning and other applications. At the National Energy Laboratory of Hawaii (NELHA), once the locus of OTEC research and pilot programs, there are no longer any functioning, net energy-producing OTEC plants, but research into uses for deep seawater pumped to the surface using OTEC technology continues. Cold, deep seawater brought up by OTEC pipes is nutrient-rich-parasite and free, and can be pumped into onshore ponds producing algae or other products in a controlled system [3].At NELHA, private companies have already profited from raising lobsters, flounder, and high-protein algae in mariculture ponds fed by the cold water. Additionally, this cold water has been used to grow temperate crops such as strawberries in Hawaii’s tropical climate [4].Air conditioning and industrial cooling may be the most lucrative of all ancillary benefits of OTEC plants .Currently, both of the two main buildings at the NELHA lab are effectively air conditioned by cold seawater pumped through OTEC pipes [5].[6]