Ocean thermal energy
Ocean thermal energy (OTE) or ocean thermal energy conversion (OTEC) is based on the thermodynamic heat pump principle and a specific thermal characteristic of oceans, especially intertropical oceans.
In the intertropical region, surface water heated by the sun can reach a temperature of 25°C while deep water remains between 2 and 4°C. This thermal gradient can therefore be used to provide cold and hot sources for a heat pump.
Thanks to this 20°C difference and large volumes of water, an OTE plant can produce heat and electricity, as well as provide a cooling system and by-products (nutritional salts, fresh water with very little pollution, etc.) for different coastal activities.
Sagar-Shakthi, a 1 MW Indo-Japanese OTE pilot centre. © Eurocéan, Wikimedia GFDL & CC by-sa 3.0