For many years, scientists have been aware of one enormous reservoir of energy on the earth's surface: the oceans. As sunlight falls on the oceans, its energy is absorbed by seawater. The oceans are in one sense, therefore, a huge "storage tank" for solar energy. The practical problem is finding a way to extract that energy and make it available for human use.

The mechanism suggested for capturing heat stored in the ocean depends on a thermal gradient always present in seawater. Upper levels of the ocean may be as much as 36°F (20°C) warmer than regions 0.6 mile (1 km) deeper. The technology of ocean thermal energy conversion (OTEC) takes advantage of this temperature gradient.

An OTEC plant would consist of a very large floating platform with pipes at least 100 feet (30 m) in diameter reaching to a depth of up to 0.6 mile (1 km...