Agencies
New Delhi
The Geological Survey of India has calculated that India can potentially generate 10GW of power from geothermal resources.
India’s energy demand is pegged to be the highest globally during 2021-30, and the country is pushing capacity addition for renewable energy to meet the twin goals of energy security and reducing emissions. While the country estimates that there is potential to develop 10 gigawatts (10GW) of geothermal capacity, this segment has received little attention in India’s ambitious green plans.
India plans to add 500 GW of renewable energy capacity by 2030, most of which will be from wind and solar. The country has taken baby steps in the geothermal sector. But can the country push geothermal energy with the same vigour with which it has added solar and wind energy? Before we analyse the opportunity, let’s understand what geothermal energy is.
Geothermal energy involves harnessing heat from deep within the earth’s crust. Deep wells are fitted with turbines that convert steam into electrical energy, which is then connected to a power grid supply.
While countries such as the US, Indonesia and Philippines have aced this energy sector, India is still warming up to it. From deserts to mountain peaks, India has immense scope for geopower. The Geological Survey of India has calculated that India can potentially benefit from around 10GW of power from geothermal resources. The energy generated could be used to provide electricity for settlements in difficult terrains, and gradually replace fossil-fuel dependency.
Through short-hole drilling in the 1970s, the Geological Survey of India has estimated around 350 sites in the country which have scope to generate geothermal energy, with Ladakh being the most promising location. Oil and Natural Gas Corporation Ltd (ONGC) has pioneered the establishment of this set-up in India. Recently, they’ve attempted to drill two wells in the Puga Valley in Ladakh.
“There are many ifs and buts down below, but we are not disheartened. First we have to establish that geothermal potential exists in India,” said Ravi, director-general of the ONGC Energy Centre Trust.
Drilling began in the Puga Valley project in August last year, a partnership between Maharatna public sector unit (PSU) ONGC and Icelandic firm ISOR. The team achieved 40 metre depth which measured a temperature of 140 degrees Centigrade. Cuttings of quartzite, pyrite and silica discovered there indicate an achievable temperature of at least 200 degrees Centigrade, given that these crystals only form in that range of temperatures. However, due to shallow reservoir activities, bad weather conditions, equipment and chemical requirements, the drilling was abandoned.
Ravi said that drilling at such high altitudes can be challenging as there is a small window of time in which the weather allows exploratory activities. ONGC plans on completing the two-phase drilling of the wells between August and October this year at Puga and Chumathang, 12 kilometres away from each other. If the two reservoirs are interconnected, then it could form a mega reservoir with a geothermal potential of 200 megawatts. This project could “change the face value of Ladakh,” Dwivedi said.
“We are very hopeful that when we go to our target depth of around 1000 metres, the temperature will definitely be around 220 degrees Centigrade,” Ravi said.
Water boils at lower temperatures at higher altitudes, thus furthering the scope of harnessing steam in these locations. ONGC has signed an MoU with the Ladakh administration for installation of a 1 megawatt plant at Puga. Testing of the reservoir will determine its potential, type of reservoir, turbines required, etc. A pilot project in India, Puga and Chumathang will set a standard for further projects to come and will establish the capacity and economic viability of geothermal energy in the country.
