OCEAN ENERGY

 

    • Oceans occupy more than 70 per cent of earth’s surface and are an inexhaustible source of renewable energy
    • India is estimated to have a potential of around 54 GW of ocean energy – tidal power (12.45 GW) and wave power (41.3 GW)
      • Promising locations are Gulf of Khambhat & Gulf of Kutch (GJ), Sunderbans (WB), Western Coast of Maharashtra, Goa, Karnataka, Kerala, Kanyakumari, Southern tip of India
    • Leading countries in Ocean Energy technology are UK, USA, Sweden, Canada, France, South Korea

The energy from oceans can be harvested in the following forms:

      • Tidal Energy
        • The difference in water level from low tide and high tide is potential energy that can be harnessed.
        • Similar to hydropower generated from dams, tidal water is captured in a barrage across an estuary during high tide and forced through a turbine during low tide
      • Wave Energy
        • Wave energy is generated by the movement of a device either floating on the surface of the ocean or moored to the ocean floor by the force generated by the ocean waves
        • The kinetic energy pumps fluid through turbines and generates electric power
      • Current Energy
        • Kinetic energy can be captured from the ocean currents, and other tidal currents with submerged turbines that are very similar in appearance to miniature wind turbines
        • Similar to wind turbines, the movement of the marine current moves the rotor blades to generate electric power
      • Ocean Thermal Energy Conversion (OTEC)
        • Ocean thermal energy conversion, or OTEC, uses ocean temperature differences from the surface to depths lower than 1,000 meters, to harness energy. A temperature difference of even 20°C can yield energy efficiently

  • In fact, it has been about 40 years since India started efforts to assess and harness tidal power, but it is yet to achieve any solid breakthrough in its development even as the country made rapid strides in boosting other sources of renewable power.
  • One of the reasons, according to the ministry, for not pursuing tidal power is “exorbitant cost”.
    • India had started two tidal power projects of 3.75 megawatts and 50 megawatts installed capacity in 2007 and 2011 in West Bengal and Gujarat respectively. But both these projects were dropped because of exorbitant costs
  • Apart from disproportionately high cost, “adverse environmental impacts that have not yet been fully documented” is another reason for the authorities to not actively pursue tidal power projects.
  • Other impacts that need consideration
    • Many birds that rely on the tide uncovering the mudflats for feeding could be affected.
    • Further, damages like reduced flushing and erosion can change the vegetation of the area and disrupt the ecological balance
  • Considering the contribution to reduce the impact in climate change, there is need of more investments into research, to make the ocean energy extraction feasible