Ocean thermal energy conversion (OTEC) is the method of generating electrical energy which uses difference in temperature that exists between shallow and deep waters of the oceans. Sun continuously warms oceans’ surfaces which cover about 70% of the Earth’s surface and in this process considerable temperature difference is creating itself, between surface and deep waters and can be used for generating enormous quantities of electrical energy with advantage that it doesn’t pollute environment nor exhaust dangerous greenhouse gases. Warm surface waters and cold deep waters are the result of ocean streams which are heating the water in parts of the ocean near the equator, and cooling water in areas near North Pole and this cold water streams on ocean’s bottom towards equator.
The basic principle of generating electrical energy is quite simple. Warm surface water is used for heating the liquid that has low boiling temperature (like propane gas), created steam is driving turbines of the electrical energy generators, and afterwards this steam is cooled by the cold water from ocean’s deep and with which gets transformed back to liquid state. Total amount of the energy which can be gained by using this method of energy transformation is one to two orders of magnitude bigger from other methods of exploiting ocean’s energy like for instance using wave power or tide power. Big problem when using this form of energy is expensive equipment and small total efficiency of the process. Because of small total temperature difference efficiency is small, it is between one and three percent. Major advantage of this process is the ecological purity of gained energy and enormous stores of this energy that can be used.
For more detailed information’s featuring exploitation of this form of energy check this video clip: