Context: The government has approved a proposal to declare ocean energy as Renewable Energy.

Accordingly, the Ministry of New and Renewable Energy has clarified to all the stakeholders that energy produced using various forms of ocean energy such as tidal, wave, ocean thermal energy conversion etc. shall be considered as Renewable Energy and shall be eligible for meeting the non-solar Renewable Purchase Obligations (RPO).

Potential of oceans as a renewable energy source:

Oceans cover more than 70% of Earth’s surface, making them the world’s largest solar collectors.

The ocean can produce two types of energy: thermal energy from the sun’s heat, and mechanical energy from the tides and waves. These energies are non-polluting, reliable, and very predictable.

1. Tidal energy: Tidal Energy, also known as Tidal Power is classified as an alternate energy or better known as the renewable source of energy. It is one of the forms of hydropower energy that exercises energy of the oceanic tides to generate electricity. 
2. Ocean wave energy: It uses the power of the waves to generate electricity. Unlike tidal energy which uses the ebb and flow of the tides, wave energy uses the vertical movement of the surface water that produce tidal waves.
3. Ocean thermal energy: The sun’s heat warms the surface water a lot more than the deep ocean water, and this temperature difference creates thermal energy. 
4. Ocean current energy: The energy of ocean currents under the surface is comparable to the wind above it. Underwater turbines — large propellers tethered to the seabed — are used to derive power from this source.
5. Osmotic energy: This technique — the most surprising — produces energy from the movement of water across a membrane between a saltwater reservoir and freshwater reservoir.

Potential:

Total identified potential of Tidal Energy is about 12455 MW, with potential locations identified at Khambat & Kutch regions, and large backwaters, where barrage technology could be used.

The total theoretical potential of wave energy in India along the country’s coast is estimated to be about 40,000 MW – these are preliminary estimates. This energy is however less intensive than what is available in more northern and southern latitudes.