It may appear ludicrous to look at the sea as a source of renewable energy as it is associated more with Tsunami and frolicking beaches. Sea is also the ultimate resting place for many big rivers as well as final destination of industrial and domestic effluents, treated or not. The faster melting of polar ice burgs due to global warming is predicted to cause a rise in the sea level significantly submerging many coastal areas permanently shrinking overall the land mass in not too distant future. Some geologists even predict submerging of many coastal towns in India by 2020! Doomsday predictions apart, the vast coast line in India can still be 'farmed' for energy harvesting to supplement the power needs of the country by systematic investments.
Portugal is considered the leader in harnessing energy from the sea and its first commercial scale wave power station is expected to go on stream soon. Sufficient electricity is anticipated to be generated, adequate for 1000 homes. The technology is simple converting the wave motion into electricity. Companies like Pelamis of Scotland are offering 2.25 MW plants with three generators each, sufficient for 1500 homes. 25 such plants can generate 21 MW of power which conventionally, if fossil fuel is used, would have caused emission of 60000 tons of CO2, the most dangerous green house gas responsible for adverse climatic changes being felt now. The plant in Agucadoura in northern Portugal consists of 140 meters of plastic tubes with 3.5 meter diameter floating 3 miles from the coast with 3 cylindrical wave energy converters made up of 700 tons of carbon steel The wave motions produce electricity through a 'hinges and hydraulic ram' system which is fed into a sub station on the land, through underwater cables and integrated with the power grid. Portuguese is planning to raise the share of power from renewable energy sources from 20% currently to 60% by 2020. Though government is subsidizing the program by assured buying of the power for the national grid @ 25 cents per kWh, it is a worth while long term investment considering the multifaceted advantages inherent in this visionary effort.
The potential for wave energy in India is very high considering that it has a coastal area of 7517 km and 1197 islands, most of then uninhabited. Locating the wave generators at regular intervals on the coast, avoiding big ports and harbors and major fishing centers can produce sufficient energy to meet the needs of millions of house holds at least near the coastal areas with minimum investments on distribution. There can even be SEZs and food parks with lower power requirements that can be located in coastal areas as they can capitalize the investments on wave energy projects and meet a major part of their power needs from the sea nearby.V.H.POTTY