DRDO’s geothermal plant to help tap new power source

Vijay Mohan

Tribune News Service

Chandigarh, January 27

The successful launch of the country’s first geothermal heating plant by the Defence Research and Development Organisation (DRDO) has opened the doors for exploitation of the vast geothermal potential in India.

Set up by DRDO’s Snow and Avalanche Studies Establishment (SASE) on its campus in Manali, the plant taps the heat differential above and below the Earth’s surface to achieve the desired temperature. It is a renewable, non-polluting and constant source of energy.

“The system can be used both for heating during winters as well as cooling in summers,” SASE Director Ashwagosha Ganju said. Given that India has considerable geothermal potential, this technology can be applied in several parts of the country from mountains to the deserts,” he added.

SASE spent around Rs 2 crore for developing the system, which can heat four large rooms. The cost, according to the Director, can be recovered in about five years. “We expend about 35 kW of conventional power to generate about 120 kW, he added, pointing out that the system at present was only for heating space and not generating power for other applications.

Heat is extracted from the Earth at a moderate temperature of 10-20°C, which can be enhanced up to 55-60°C through a geothermal heat pump. A synthetic ground loop heat exchanger, with total length of over 5,500 meters and a boring depth of up to 2,500 meters, is coupled to the heat pump. In this system, 27 boreholes are drilled up to the depth close to 100 m each. A fluid solution sucks heat from ground and transfers it to the pump that drives this heat to high temperature for user requirement.

India has an estimated geothermal potential of 10,000 MW with about 350 potential sites located in the Himalayas, Ladakh, Himachal Pradesh, Haryana Rajasthan, Maharashtra, Gujarat, Jharkhand, Chhattisgarh, Madhya Pradesh, Andhra Pradesh, Telangana, Sikkim, Arunachal Pradesh and the west coast.

While the Geological Survey of India has been mapping the sites since the 1970s and has been carrying out explorations and technical studies, there is no geothermal project in India so far to generate power. Over 80 countries are using geothermal technology to generate low cost green electricity.