ISR hopeful of tapping geothermal energy, starts survey

To find out potential spots for setting up India's first geothermal power plant using heat stored below earth's surface, Institute of Seismological Research (ISR) has started surveys using latest 3D Magentotelluric (MT) imaging technology.
With the initiative, the Gandhinagar-based ISR is hopeful of making a breakthrough by finding out the most feasible source of thermal energy to set up a 2 mega watt geothermal power plant in Gujarat, which will be the first in the country, ISR Director Dr B K Rastogi said.
"ISR has started geophysical surveys for geothermal energy in various parts of state. The institute has pioneered a technique of 3D MT imaging of crust to locate the best spots. Till now, geological faults and crustal structure have been mapped in Kutch," Rastogi said.

According to him, geothermal energy is stored below the surface of earth in the form of heat. This heat can help generate power, as temperature below the earth could be as high as 100-150 degrees Centigrade.
"Normal thermal power plants heat water using coal or gas to generate steam, which runs turbines. Now, we want to find pre-heated water stored beneath the earth, so that we don't have to rely on other energy sources. As of now, we are aiming to find out spots where we get water with atleast 80 degrees Centigrade temperature," the director said.
Hot water sources having 80 deg C temperature would be good enough for a geothermal power plant, he said.

"There are places in the world where geothermal power plants get direct steam due to very high temperature. But, it may not be possible here. Thus, even if we get 80 degrees C of temperature, the plant will have to boil it till it reaches 100 degrees. Thus, it will consume very less energy than boiling water which is at room temperature," Rastogi said.
"Such hot water sources are hidden as deep as 1 km below the surface. Apart from our own 3D mapping technology, we are also making use of some German technology to map such spots," he said.