Comunidad del pacífico en perspectiva - Volumen 2

LA CoMUNIDAD DEL PAclFIOO EN PERSPECTIVA / F. Orrego Vicuña oceans, and they are reasonably predictable. Wind power will sure1y be used on Pacific islands and in the Pacific rim for such tasks as pumping and perhaps, also, for the generation of moderate amount of electricity. A more directly ocean-re1ated mode of energy generation makes use of the difference in entropy between a source of heat and a sink of cool water. Land-based sources of cooling water for energy generation are in short supply, with competition for these among agricultutal; urban, and industrial uses. Thus a primary energy resource which is available in effective1y limitless quantities in the ocean, particularly in the tropical ocean, is simply cold water. The upper layers of tropical water are effectively heated by the sun, but sorne 400 to 600 meters below the surface is a vast reservoir of water a few degrees above the freezing point. The temperature difference between the warm and cold layers can be harnessed to produce energy; hence the term for the technology "ocean thermai energy conversion" or OTEe for short (Weeden, 1975). It relies on juxtaposing warm and cold water in such a fashion that a liquid of low boiling point such as Freon or ammonia can be evapo– rated and condensed, respectively, with the vapor so produced. driving a low pressure turbine. Another OTEe design would use water vapor for driving the turbines instead of organic fluids, enabling the production of fresh water as a by-product of the energy generating process. OTEe plants may be sited on the shores of islands with steep slopes, or they may be reasonably close· to, or further from the shore. Depending on distance, they could be connected to the sites of power use by high voltage transmission lines, or if they are on the high seas grazing as it were for the cold water they employ, the energy they produce could be stored in the form of liquid hy– drogen - through electrolytic disassociation of water or - as am– monia. The latter would be produced from the nitrogen in the deep water which has a nitrate content of up to lOO times that of the surface layer. Ammonia could be used as fertilizer or as a base for industrial processes and also as a hydrogen carrier for a hy– drogen energy economy. , The best regions for OTEe deployment are in the tropical seas 140