In the late 1800’s, the French physicist Jacques Arsene d’Arsonval proposed a method for generating electricity using the sea as a giant solar-energy collector. It is considered that the technology, termed “Ocean Thermal Energy Conversion” (OTEC), may enable the establishment of an efficient energy storage system across the world, supplying enough energy for our entire planet.
OTEC is based on the idea of exploiting the differences in temperature between deep waters and surface waters in order to generate electric power. Shallow ocean waters can heat up to a temperature of 29C in the tropics. Only one kilometer below these warm waters, temperatures are significantly lower, often falling below 5C. These extreme temperature differences are used to operate vapor turbines, which drive generators to produce electricity. Experts estimate that on an average day, 60 million square kilometers of tropical seas absorb an amount of solar radiation that is equal in heat content to about 250 billion barrels of oil. To get a better perspective on these numbers, this actually means that less than 0.001% of this energy converted into electric power would be sufficient to supply over 20 times the electricity consumed daily in the United States.