CAN SEAWATER BE USED AS A SOURCE OF ENERGY?
Seawater is probably one of the few natural resources that is easily accessible with minimal processing. Seawater can be converted to a more direct fuel, according to Pfeffer R and Macon W. However this requires the desalinization of seawater which in itself is a very high energy operation. If seawater is desalinized, thermochemical water splitting processes can be used to break water down to hydrogen and oxygen. This hydrogen can then be burned, combine with oxygen to form water and more importantly, energy.
Geothermal energy (from geothermal fluid) and seawater has been used for the heating and cooling of a terminal building in an airport of Thessuloniki (Mendrinos D, Karytsas C. 2003). Seawater and geothermal fluid was extracted from boreholes and the energy contained by these fluids was exchanged to a water source heat pump by using plate heat exchangers. During winter both seawater and geothermal fluid were fed into the heat pump, however in summer only 15 degrees Celsius seawater was fed into the heat pump.
The heat energy rejected by the heat pumps was absorbed by the seawater, hence providing cooling. The system is energy efficient and decreases reliance on fossil fuels (saves up to 90% of energy used by conventional air conditioning systems). Cool air is not generated by the evaporation of liquid into a gas ( as in conventional systems) but rather directly form cold deep water readily available from lakes and the sea ( http://www.aloha.com/~craven/coolair.html ).