Ocean Tidal Energy: Tapping the ocean for energy

India has a shortfall of over more than 70,000MW of energy and to fill in the shortage the government has taken many steps to utilize the elusive “renewable sources of energy”. But, has it been enough is the question we should ask?India is endowed with economically exploitable and viable hydro potential assessed to be about 84,000 MW at 60% load factor (1,48,701 MW installed capacity). In addition, 6780 MW in terms of installed capacity from Small, Mini, and Micro Hydel schemes have been assessed. Also, 56 sites for pumped storage schemes with an aggregate installed capacity of 94,000 MW have been identified. However, only 19.9% of the potential has been harnessed so far.


But, there is a long impending problem with the rivers which have been over-exploited and over-polluted due to various types of human activities going alongside the banks of these rivers. The Gangetic glacier is shrinking at the rate of 25 inches and year and it is estimated the Gangetic glacier will completely disappear by the year 2035. Further, the Yamuna is graded E river which means the water is highly polluted and with human excreta, non-biodegradable solid waste and organic compounds and will very soon lose its natural flow and this lead to a reduction in the overall energy production from the river. The Indus River again is facing such a problem and the river might change its course in the coming years.


The only way we can go beyond the rivers and still utilize the amazing potential offered by water is to tap the ocean for energy. Tidal waves are caused twice in a day once during the morning known as solar tides and second during the night called lunar tides and these usually last for ten hours or more. Tidal waves can be used to produce electricity by installing tidal barrages along the ocean creeks and using motors to harness the energy and produce electricity.


The only cost which needs to be incurred is the huge initial infrastructural investment required for building the tidal energy plant and the plant runs with almost negligible maintenance costs and the plant life is usually 35 years.


India has a potential of producing more than 7000MW of energy using this technology alone and as per a survey conducted by NHPC Ltd., India can install these plants in three locations the Gulf of Kutch, Gulf of Kambhat and Gulf of Mannar. The West Bengal Renewable Energy Development Authority (WBREDA) in has authorized NHPC Ltd., to prepare a detailed project report on Durghadhauni Mini Tidal Energy plant with a capacity of 3.65 MW installed in the Sunderbans and was developed by a joint collaboration between IIT Madras and National Institute of Ocean Technology . The plant has been made operational and is providing electricity to nearly 15000 homes.


The only area of concern here is the environmental impact of the technology as many geologists believe that the silting and de-silting of the basin might harm the oceanic organisms.


The future of energy production lies in the seas and La Rance, France is the oldest Ocean Tidal Energy Plant and has been running successfully. The European Union has commissioned extensive study of the ocean bodies of Europe and development of power plants wherever possible. India should also take appropriate steps in developing such technologies and lessening the burden on fossil fuels for energy which still amount for more than 70% of entire electricity production for India.


Ishaan Bhardawaj

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