76. OTEC Economics – The Perception and the Future

Oceans are large sources of solar energy. In the regions of tropical oceans, between approximately 15^O North and 15 ^O South latitude a temperature difference of about 20 ^OC exists between the surface water and water at a depth of 1000 m. The process of harnessing solar energy from the oceans by utilizing this temperature difference is called Ocean Thermal Energy Conversion (OTEC). OTEC is an untapped non-polluting renewable energy source which is most suitable for a tropical country like India with enormous potential. This paper discusses about the economic aspects of OTEC. Financial analysis has been carried out for a 20 MW plant and a comparison is made with other sources of power like fossil-fuel, wind, hydro etc., under Indian conditions. It is observed that land or shelf mounted OTEC plants of capacities of 20 MW and above are cost comparable. For coastal and island applications where electric power generation could be combined with mari-culture, fresh water production, supply of cold water for air-conditioning etc., OTEC would be economically attractive. India has a vast coastline of 7500 km and is a well placed tropical country for harnessing OTEC resources. It is estimated that 180,000 MW of installed capacity of OTEC power plants could be possible in India. The technology demonstration of OTEC on 1 MW range has reached closer to reality. Demonstration from 1 to 5 MW system is sufficient to step-out into 100 MW plants in high seas considering the offshore technologies available in Oil Industry. An approach to the commercialization of OTEC on Build Operate and Transfer (BOT) or Joint Venture Company (JVC) concept with proper support and incentive from Government may attract entrepreneurs and large industrial houses to enter into OTEC field.