“Ocean is the Vast Source of Energy” – Essay

The ocean which constantly receives solar radiations acts as the world’s largest natured solar collector and has potential to provide, a means of utilizing renewable energy.

It act not only as collector, but also has an enormous storage capacity. Energy from the ocean is available in several forms such as ocean thermal energy, wave energy, tidal energy, ocean currents etc.

(i) Ocean Thermal Energy:

There exists a temperature difference of 20°C between the warm surface water of the ocean and the cold water and this natural temperature can be used to generate energy. In the ocean thermal energy conversion plant, the warmer water from the surface with the temperature of 24- 30°C is brought into one pipe and the cold water at the temperature of about 4-8°C is brought in another pipe in the depth of 1000 meters.

These two pipes are used in conjunction with fluid such as ammonia, propane or neon. The warm water evaporates liquid ammonia into vapour at high pressure and is made to pass through a turbine which rotates it and generate electricity.

The ammonia vapour coming out of the turbine is condensed back into liquid ammonia by cooling it with the cold sea water brought up from the deep part and the liquid ammonia is then pumped back to the evaporator, thus completing the cycle.

The energy from OTEC can be converted into either electrical, chemical. Being a tropical country, India has the OTEC potential of about 50,000 mw.

The most promising site identified as far is in Lakshadweep Islands where the necessary geographical conditions for a shore based OTEC plant exist. India has also tied up with a USA’s firm to set up an Ocean thermal energy conversion plant in Tamil Nadu.

(ii) Tidal Energy:

Among the different ocean energy sources, technology for harnessing the energy from the movement of tidal has been developed commercially. France, Russia, China Canada, UK and Korea are some of the leading countries which are making use of tidal energy on commercial basis.

In India, some potential sites for tapping tidal energy are in the Gulf of Kuchch, Gulf of Cambay in Gujarat and the Delta of the River Gangas in the Sunderbans region of the West Bengal. The Ministry of Non-conventional Energy Sources has supported the setting up of the first demonstration tidal protect at demonstration tidal power project at Durgaduani Creek in the area of West Bengal through the West Bengal Renewable Energy Development Agency.

The main objective of the Project is to supply power to 11 remote and unelectrified villages. Tidal energy is generated by constructing a dam across a narrow opening to the sea. The water moves in and out of the opening in the dam during high and low tides.

(iii) Wave Energy:

Wind blowing across the surface of the oceans into waves which is an up and down movement of water. The kinetic energy possessed by the huge amount of water wave can be harnessed to convert it into usable form of energy.

According to an estimate, the total amount of power released by waves striking the shorelines across the world is estimated to be 2-3 million megawatts but there are limited number of sites and technology available to harness this energy fruitfully.

The areas with an average energy density of 40 mw per kilometer of coastal line are considered to be economically viable for generating electricity from ocean waves. The tropical coastline of India, especially south-west coastline is very suitable for establishing such energy plants.

The Department of Ocean Energy Development has estimated that the wave energy potential in India is about 40,000 mw. The ocean energy cell has established a pilot power plant at vizhijam, Kerala of 120 mw capacities during monsoon period and 30 mw during non-monsoon period.