Geothermal Energy

Syllabus: GS1/Physical Geography, GS3/Renewable Energy

Context

• India’s geothermal push gained momentum with the commissioning of its first two geothermal wells at Puga Valley, Ladakh, opening prospects for round-the-clock renewable power.

About Geothermal Energy

• Geothermal energy harnesses the natural heat within the Earth to generate electricity or provide direct heating and cooling.
• It is weather-independent and available round the clock, unlike solar and wind, making it a potential source of firm renewable energy.
• Earth’s internal heat arises from radioactive decay of uranium, thorium and potassium and residual heat from planetary formation.
• In geologically active regions, faults and fractures allow heat to approach the surface, creating reservoirs of hot water and steam.

How does it generate power?

• Deep wells bring hot water/steam to the surface.
• Steam drives a turbine connected to a generator.
• Condensed water is reinjected into the reservoir, supporting continued production.
• Geothermal heat can also be directly used for district heating, agriculture, aquaculture and space heating/cooling.

India’s Geothermal Potential

• India’s diverse geology provides significant geothermal opportunities.
• 381 hot springs mapped by the Geological Survey of India (GSI).
• 10 geothermal provinces identified.
• Theoretical geothermal potential: nearly 10.6 GW (10,600 MW).
• 42 sites recognised as promising for power generation and direct heat use.
• Major provinces include Himalayan, Naga-Lusai, Andaman & Nicobar, Son-Narmada-Tapi (SONATA), West Coast, Cambay Graben, Aravalli, Mahanadi, Godavari and South Indian Cratonic regions.

Puga Valley: A Landmark Development

• In July 2026, ONGC Energy Centre commissioned India’s first two geothermal wells at Puga Valley, Ladakh, located at an altitude of over 14,000 feet.
• The two wells are 1,000 metres deep and will facilitate reservoir evaluation and pave the way for India’s first 1-MW demonstration geothermal power project.
• Temperatures of up to 135°C have been recorded beneath Puga Valley, according to the infographic on page 2 of the source document.

Emerging Applications & Projects

• India is moving from resource assessment towards field demonstrations:
  • Ankleshwar, Gujarat: Pilot to assess electricity generation by retrofitting unproductive oil and gas wells.
  • Gandhinagar, Gujarat: Solar-geothermal demonstration; three wells produce geothermal fluid at 70–80°C, with 50–90 kW electricity generation demonstrated.
  • Tawang, Arunachal Pradesh: Geothermal assessment at five sites.
  • Hyderabad: Development of geothermal cooling for air-conditioning.
  • Shallow geothermal: Borehole Heat Exchangers being studied for heating and cooling.

Key Concerns in Geothermal Energy

• High Upfront Cost: Deep drilling, exploration and reservoir assessment require substantial capital; resource uncertainty increases financial risk.
• Geological Uncertainty: India’s geothermal resources are unevenly distributed, and identifying commercially viable reservoirs requires extensive geological and geochemical surveys.
• Induced Seismicity: Fluid injection/reinjection, particularly in Enhanced Geothermal Systems (EGS), can trigger micro-earthquakes and, in some cases, larger seismic events.
• Water-related Concerns: Geothermal operations may require significant water, while poor management can affect groundwater availability or quality.
• Environmental Impacts: Potential issues include land disturbance, gas/mineral release, thermal pollution and groundwater contamination if geothermal fluids are not properly managed.
• Technological Challenges: EGS/AGS, deep drilling and efficient reservoir management require advanced technology and specialised expertise.
• Resource Depletion: Poorly managed extraction can reduce reservoir pressure/temperature, affecting long-term productivity.
• Remote Locations: Many promising Indian sites, such as Puga Valley in Ladakh, are geographically difficult to access, increasing infrastructure and transmission costs.
• Limited Commercial Experience in India: Despite a theoretical potential of ~10.6 GW, India is still at the demonstration stage; commercial-scale geothermal power generation is yet to be established.
• Regulatory & Investment Challenges: Large-scale deployment requires clear regulations, risk-sharing mechanisms, private investment and reliable geothermal resource data.

Policy Push

• The National Policy on Geothermal Energy, 2025, with MNRE as nodal ministry, seeks to make geothermal energy a major renewable-energy pillar. It promotes:
  • Research, drilling and reservoir management;
  • Ground Source Heat Pumps (GSHPs);
  • Repurposing abandoned oil and gas wells;
  • National geothermal data repository;
  • Pilot projects and Centres of Excellence;
  • Greater public-private participation;
• The RE-RTD programme supports indigenous and cost-effective geothermal technologies.

Way Forward

• India’s theoretical potential remains largely untapped, while commercial-scale geothermal power generation is yet to be established.
• Enhanced Geothermal Systems (EGS) and Advanced Geothermal Systems (AGS) can expand exploration beyond conventional geothermal zones.
• International cooperation with Australia, Iceland and Saudi Arabia can further support technology development and knowledge exchange.
• Globally, installed geothermal capacity reached 15.67 GW by end-2025, with Indonesia, the US, Philippines, Türkiye and New Zealand accounting for around 67%.

Source: PIB