Ocean Thermal Energy Conversion (OTEC) uses the temperature difference between cooler deep and warmer shallow or surface ocean waters to run a heat engine and produce useful work, usually in the form of electricity. However, the temperature differential is small and this impacts the economic feasibility of ocean thermal energy for electricity generation.
The most commonly used heat cycle for OTEC is the Rankine cycle using a low-pressure turbine. Systems may be either closed-cycle or open-cycle. Closed-cycle engines use a working fluids that are typically thought of as refrigerants such as ammonia or R-134a. Open-cycle engines use vapour from the seawater itself as the working fluid.
OTEC can also supply quantities of cold water as a by-product. This can be used for air conditioning and refrigeration and the fertile deep ocean water can feed biological technologies. Another by-product is fresh water distilled from the sea.
Demonstration plants were first constructed in the 1880s and continue to be built, but no large-scale commercial plants are in operation.
Read more about Ocean Thermal Energy Conversion: History, Thermodynamic Efficiency, Cycle Types, Land, Shelf and Floating Sites, Some Proposed Projects, Political Concerns, Cost and Economics, Thermodynamics, Environmental Impact, Cold Air/warm Water Conversion
Famous quotes containing the words ocean, energy and/or conversion:
“The frost was on the village roofs as white as ocean foam;
The good red fires were burning bright in every ‘longshore home;
The windows sparkled clear, and the chimneys volleyed out;
And I vow we sniffed the victuals as the vessel went about.”
—Robert Louis Stevenson (1850–1894)
“Because humans are not alone in exhibiting such behavior—bees stockpile royal jelly, birds feather their nests, mice shred paper—it’s possible that a pregnant woman who scrubs her house from floor to ceiling [just before her baby is born] is responding to a biological imperative . . . . Of course there are those who believe that . . . the burst of energy that propels a pregnant woman to clean her house is a perfectly natural response to their mother’s impending visit.”
—Mary Arrigo (20th century)
“The conversion of a savage to Christianity is the conversion of Christianity to savagery.”
—George Bernard Shaw (1856–1950)