World Environment Day 2023 | India’s digging deep, to harness its geothermal energy

Drilling at high altitudes can be challenging, as the weather allows only a small window of time for exploratory activities. (Representational image: Kerry via Pexels)

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.

What is geothermal energy?

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.

Story so far

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.

We are very hopeful that when we go to our target depth of around 1000 metres (at Puga and Chumathang), the temperature will definitely be around 220 degrees Centigrade

- ONGC Energy Centre Trust director-general Ravi

Ravi did not comment on this question when asked, stating that it's a pilot project in India. First, the potential has to be established, only then can costs be ascertained. However, as per a report by the International Renewable Energy Agency, these are the Levelised Cost of Electricity (LCOEs) for (as of 2020)

1. Onshore wind: $0.041/kWh,

2. Geothermal energy: $0.07/kWh GE

3. Solar photovoltaics: $0.057/kWh

Thus, geothermal is a little pricier, but with evolving markets and technologies, the price should reduce, just like they have for solar energy which was around ₹16 for a unit 10 years ago and less than ₹3 now, Ravi added.

Asked about the environmental impact of drilling this deep in regions like Ladakh, Ravi did not mention any harmful effects of drilling on the environment, since it occurs deep beneath the Earth's surface.

As per the US Energy Information Administration (eia.gov), there are a few disadvantages mentioned with respect to drilling of OIL wells. "Exploring and drilling for oil may disturb land and marine ecosystems. Drilling an oil well on land often requires clearing an area of vegetation. However, technologies that significantly increase the efficiency of exploration and drilling activities also reduce effects on the environment."

Rocky road ahead

Establishing geothermal wells is an extremely capital-intensive project. ONGC is also planning to initiate another R&D project in Gujarat’s Cambay area, which requires drilling to a depth of 3,000 metres.

Benson Ireri, Africa Lead at the World Resources Institute (WRI), said that the two main reasons for lack of emphasis on geopower is a deficit of research and funding. “I think the risk of cost for it, is the amount of investment that needs to go in terms of exploration, when you find, for example, a single well, is it viable financially, is a big gamble,” he explains.

And drilling one well costs approximately $5 million (around Rs 41.2 crore), according to the US government’s Geothermal Technologies Office. Only after successful execution of a project, can tariff rates and other cost economy factors be determined. “From a research point of view, I think getting to see how and what can be done, in terms of research, and getting to build some better understanding of the sector, could also be one of the key things that further help progress in this space,” said WRI's Ireri.

Hellisheiði Power Station in Iceland. Geothermal energy stations are compact, have a low-carbon footprint and use less land per gigawatt hours than coal (3642 sq m), according to the US Department of Energy. (Photo by Kevstan via Wikimedia Commons 4.0)

Learnings from other developing nations

Kenya is the world’s seventh largest producer of geothermal power, with an operational capacity of 800 megawatts. What kickstarted Kenya’s journey in geothermal energy was a hunt by the government in the early 2000s for alternative renewable resources, since hydropower was unreliable during droughts. Talks with private investors led to the formation of the government-owned Geothermal Development Corporation (GDC) in 2008, with loan-based financial backing from the World Bank and the African Development Bank. The GDC took responsibility for the risks associated with the experimental drilling, which lured private investors to conduct GE drilling operations. Foreign investments such as those from Japan followed soon after. Since then, Kenya has also introduced geothermal energy courses in universities to train their own people for the industry.

Ireri said that collaborations between drilling companies and universities can enhance research in the domain, with scholarships as additional incentives. India can learn from Kenya and adopt similar measures, while adapting to the subcontinent’s demand and thresholds.

The perks of geo-power are many. Since it’s harnessed from deep below the surface of the Earth, it is a continuous source of energy. Solar and wind, on the other hand, are variable renewables, which fluctuate with weather conditions. Geothermal energy stations are compact, have a low-carbon footprint and use less land per gigawatt hours than coal (3642 m2), according to the US Department of Energy. Energy experts believe geothermal power can supplement the high energy-requirements of producing green hydrogen.

As India sets out for net zero carbon emissions by 2070, it could bridge the energy gap and help India build a diversified clean energy portfolio.