Sustainable Technologies
Ask questions and provide feedback

Public policy
Dig deeper
Thermal Energy Conversion
Ocean, Thermal Energy Conversion
Water in the deep ocean is many degrees cooler than surface temperature water. The difference in temperature can be used to run a heat engine either using the water itself in an open-loop (placing warm ocean water in a low pressure system causes it to boil), or by transferring the heat energy to a closed-loop system with a heat exchanger and a low-boiling point liquid such as ammonia.

Some open-loop OTEC designs can also create desalinated water as a byproduct.

Cool deep water from oceans or deep lakes (typically at a constant 4 °C or 40 °F) can also be used for purposes of air conditioning, reducing the demand side electrical loads of buildings that are sited to take advantage of this. A similar effect can be utilized in almost any location via ground source heat sink loops.