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Topic– Part of static series under the heading – “Ocean energy”
6) Discuss the potential of oceans as a renewable energy source? Also discuss the potential of such energy source in india?(250 words)
Key demand of the question
The question expects us to discuss the main form of renewable energy that can be harnessed from the oceans, the technology available, the challenges faced. In the second part , we need to highlight where all in India can such energy be harnessed and the potential of such energy resource in India.
Discuss – Here your discussion should focus on explaining the various facets of energy resources that can be harnessed from the oceans and the places in India having such potential.
Structure of the answer
Introduction – Mention that ocean can produce two types of energy: thermal energy from the sun’s heat, and mechanical energy from the tides and waves. The fact that the marine renewable sector is less well developed than other energy industries presents companies with both opportunities and challenges
- Explain how tidal energy works – Energy can be extracted from tides by creating a reservoir or basin behind a barrage and then passing tidal waters through turbines in the barrage to generate electricity. Tidal energy is extremely site specific requires mean tidal differences greater than 4 meters and also favorable topographical conditions, such as estuaries or certain types of bays in order to bring down costs of dams etc. Discuss the challenges in utilizing this energy source – intermittent supply, cost, altering ecosystem at bay, limited time in the day when it can work when the tides increase, power transmission etc
- Highlight the potential of tidal energy in India – Since India is surrounded by sea on three sides, its potential to harness tidal energy has been recognized by the Government of India. The most attractive locations are the Gulf of Cambay and the Gulf of Kachchh on the west coast where the maximum tidal range is 11 m and 8 m with average tidal range of 6.77 m and 5.23 m respectively. The Ganges Delta in the Sunderbans in West Bengal also has good locations for small scale tidal power development. The maximum tidal range in Sunderbans is approximately 5 m with an average tidal range of 2.97 m. The identified economic tidal power potential in India is of the order of 8000-9000 MW with about 7000 MW in the Gulf of Cambay about 1200 MW in the Gulf of Kachchh and less than 100 MW in Sundarbans
- Explain ocean wave energy is captured directly from surface waves or from pressure fluctuations below the surface. Wave power systems convert the motion of the waves into usable mechanical energy which in lump can be used to generate electricity. Mention that it can be harnessed with the help of float or buoy systems, oscillating water column devices etc. Highlight challenges such as – variable energy supply, suitable site requirement, high cost etc.
- Discuss the potential in India – The potential along the 6000 Km of coast is about 40,000 MW. This energy is however less intensive than what is available in more northern and southern latitudes
- Explain ocean thermal energy – The main objective of ocean thermal energy or Ocean Thermal Energy Conversion (OTEC) is to turn the solar energy trapped by the ocean into useable energy. OTEC systems use the ocean’s natural thermal gradient”the fact that the ocean’s layers of water have different temperatures to drive a power-producing cycle.
- Mention that its potential is likely to be around 180,000 MW and is still evolving
Conclusion – Highlight the need for India to diversify its energy sources and discuss the potential of harnessing energy from waves.