Geothermal energy—the heat derived from the earth’s interior—is emerging as a critical pillar in India’s quest for a diversified renewable energy basket. For the UPSC exam, understanding the geographical distribution of these heat sources is vital for GS Paper I (Geography) and GS Paper III (Energy & Environment).

Unlike solar or wind, geothermal energy provides baseload power, meaning it is available 24/7, unaffected by weather conditions. The Geological Survey of India (GSI) has been at the forefront, mapping the nation’s thermal anomalies to harness this “green heat.”

16 Major Geothermal Energy Sites Identified by GSI

The GSI has identified 16 specific sites with high potential for development. These are often associated with hot springs and tectonically active zones.

S. No.Geothermal SiteState / UTRegion/Significance
1Puga ValleyLadakhHighest potential in India; Pilot project site.
2ChumathangLadakhHimalayan belt.
3Panamik (Nubra)LadakhNorthernmost thermal spring.
4ManikaranHimachal PradeshParvati Valley; religious & energy site.
5TattapaniHimachal Pradesh“Hot water” in local dialect.
6TapovanUttarakhandProximity to Joshimath.
7YamunotriUttarakhandHigh-altitude thermal activity.
8GangananiUttarakhandPart of the Bhagirathi valley.
9Tshachu (Tawang)Arunachal PradeshEastern Himalayan segment.
10YumesamdongSikkimHigh-temperature sulfur springs.
11SohnaHaryanaNear the Aravalli ridge.
12BhimbandBiharMunger district.
13SurajkundJharkhandHazaribagh district.
14BakreshwarWest BengalKnown for helium emission.
15TattapaniChhattisgarhPart of the SONATA province.
16UnhavareMaharashtraWest Coast geothermal belt.

The 10 Geothermal Provinces of India

Beyond individual sites, the GSI categorises India’s geothermal potential into 10 broader provinces based on geological tectonics and heat flow.

  1. Himalayan Geothermal Province: Characterised by high-temperature springs due to the collision of the Indian and Eurasian plates.
  2. Naga-Lusai: Associated with the Tertiary fold belts of the Northeast.
  3. Andaman Nicobar Islands: Linked to volcanic activity (Barren Island).
  4. Son-Narmada-Tapi (SONATA): A major rift zone stretching across Central India.
  5. West Coast: High heat flow along the fault lines of the Konkan region.
  6. Cambay Graben: Located in Gujarat, associated with high sedimentary thickness.
  7. Aravalli: Relic mountain range with deep-seated faults.
  8. Mahanadi: Basin-related thermal activity in Odisha.
  9. Godavari: A major rift valley in Southern India.
  10. South India Cratonic: Stable continental lithosphere with localised thermal anomalies.

UPSC Perspective: Why it Matters

In the context of Net Zero 2070, geothermal energy offers a solution to the “intermittency” problem of renewables. For the Mains, aspirants should link this to Sustainable Development Goal 7 (Affordable and Clean Energy) and the National Strategy on Geothermal Energy.

Challenges in Development

While the potential is vast (estimated at 10,000 MW), several hurdles remain:

  • High Initial Cost: Exploration and drilling are capital-intensive.
  • Location: Most sites are in remote, high-altitude, or ecologically sensitive areas (e.g., Ladakh, Sikkim).
  • Technical Expertise: India still requires advanced technology for deep-well drilling in hard crystalline rocks.

Prelims & Mains Pointer

Quick Facts for Prelims

  • Highest Potential: Puga Valley, Ladakh (Often termed as India’s “Geothermal Capital”).
  • Agency: Geological Survey of India (GSI) and MNRE are the nodal bodies.
  • Mechanism: Uses the Earth’s internal heat (200 C – 350 C at these sites) to produce steam and drive turbines.
  • Comparison: Unlike coal, it emits nearly zero CO2.

Potential Mains Question

“Evaluate the geographical distribution of geothermal energy resources in India. Discuss the socio-economic and technical challenges in harnessing this energy to achieve India’s climate commitments.” (15 Marks, 250 Words)

Geothermal energy is the heat derived from the Earth’s interior, providing a clean, reliable, and baseload renewable energy source. With an estimated potential of 10,600 MW, it is pivotal for India’s Panchamrit targets and the goal of Net Zero by 2070.

1. Geographical Distribution of Geothermal Resources The Geological Survey of India (GSI) has identified 381 thermally anomalous sites grouped into 10 Geothermal Provinces:

  • Himalayan Province: The most promising belt (e.g., Puga Valley in Ladakh and Manikaran in Himachal). High-enthalpy reservoirs are found here due to plate tectonics.
  • SONATA (Son-Narmada-Tapi): A major rift system in Central India including sites like Tattapani (Chhattisgarh).
  • Cambay Graben: Located in Gujarat; high potential for heat extraction from sedimentary basins and abandoned oil wells.
  • West Coast: Fault-bound zones in Maharashtra (e.g., Unhavare) with moderate temperature gradients.
  • Other Regions: Significant potential also exists in the Godavari and Mahanadi basins, and volcanic regions like Andaman and Nicobar Islands.

2. Socio-Economic Challenges

  • Remote Locations: Most high-potential sites (like Ladakh or Tawang) are in rugged, sparsely populated terrains, making power evacuation to the national grid difficult and expensive.
  • High Upfront Capital: Geothermal projects have a high gestation period and high initial drilling costs (approx. ₹20-30 crore per MW), deterring private investment.
  • Conflict with Tourism/Culture: Many sites are associated with religious hot springs or fragile ecosystems, leading to local resistance or ecological concerns.

3. Technical Challenges

  • Exploration Risk: Geothermal drilling carries a “resource risk”—significant capital is often spent before confirming the reservoir’s commercial viability.
  • Hostile Environments: In Ladakh, operations are limited to a 3-4 month window due to extreme sub-zero temperatures and low oxygen.
  • Technological Gaps: India is still developing indigenous expertise in Enhanced Geothermal Systems (EGS) and specialized drilling rigs capable of handling high-pressure steam and abrasive rocks.

Conclusion The launch of the National Policy on Geothermal Energy (2025) and the pilot success at Puga Valley mark a paradigm shift. By integrating geothermal energy with solar and wind, India can ensure a stable, 24/7 green grid, turning its geological heat into a cornerstone of sustainable development.

Mentor’s Tip for 2026

Data Point: Cite that the Puga Pilot Project (led by ONGC and Seros) aims to initially generate 1 MW, scalable to 10 MW.

Keyword to include: Mention “Binary Cycle Technology”—it is being used in Puga Valley to generate power from moderate-temperature water.