It is widely discussed fact that the world is facing an energy crisis. All our major resources of power are diminishing in strength and demand is increasing steeply. In a few decades world?s petroleum resources will be emptied. This fact had been made scientist all over the world to think of energy resources which are everlasting.(perennial, renewable) One big step to the exploration of such renewable energy source is the conversion of ocean thermal energy. As we all know energy is the basic resource for the nation?s economic development. The role of energy play a very important role in the production or service in all sectors of economy, industry, transportation, commerce and reliability of supply and quality of energy resources are deteriorating. It is only since 1973 that the constraints of the several finite fossils and fissile resources which are over graduate of economic growth and high standards of living have begun to be appreciated. In addition to scarcity of materials and energy, environment and ecology constrain are placing limitations on exploitation of natural resources. The industrialised and developing world must work together to ensure energy efficient technology and sustainable energy options. Renewable energy resources are vast and free, but there extraction may be costly. Economic conditions, quality and type of energy needed by the end-user play a crucial role in the technology developments. Here the concept of ocean thermal energy conversion as a renewable source has been discussed.