The Hindu Business Line : NTPC plans foray into geothermal energy

New Delhi May 2 NTPC Ltd is mulling a foray into geothermal energy and is looking at the possibility of setting up a geothermal power plant of 30-50-MW as part of its diversification plans.

The company is on the look out for sites for its first geothermal station. Possible locations under consideration include Puga Valley in Ladakh, Manikaran in Himachal Pradesh and some hot-spring sites in Uttaranchal, which have potential for development of power using heat generated from within the earth, a Government source said.

Geothermal power is a renewable energy source whereby electricity is harnessed from the intense heat present in rocks inside the earth's crust. These power plants use steam, heat or hot water from geothermal reservoirs to provide the force that spins the turbine generators and produces electricity. The used geothermal water is then returned down an injection well into the reservoir to be reheated and to sustain the reservoir.

NTPC's proposed venture, at extremely initial stages, could cost around Rs 500 crore, which translates into a cost of Rs 9-10 crore per MW as compared to around Rs 4-4.5 crore per MW for a greenfield thermal station. The high initial cost of building such a plant compared with conventional thermal plants is one of the factors inhibiting the development of geothermal capacities.

India currently does not have any commercial scale geothermal-based power projects. Individual geothermal power plants can be as small as 100 kW or as large as 100 MW depending on the energy resource. The three countries with the largest amount of installed direct heat use capacity are USA (5,366 MW), China (2,814 MW) and Iceland (1,469 MW), accounting for 58 per cent of world capacity, which has reached 16,649 MW, according to US Department of Energy data. Chevron Corporation is among the largest producer of geothermal energy.

NTPC, which has largely been a coal-based power generator, has been attempting to diversify into other forms of power generation, including nuclear, hydroelectric and even wind-based projects, in order to bring down its dependence on fossil fuels and add cleaner sources to its fuel mix.