What is Geothermal Energy?

Geothermal energy is a renewable energy source derived from the Earth's internal heat, utilized for electricity generation and direct heating applications in regions with suitable geological conditions.

Key Characteristics

  • Nature: Steady, low-carbon, and weather-independent renewable energy source
  • Formation: Earth's internal heat generated through radioactive decay of uranium, thorium, and potassium, along with residual heat from planet's formation
  • Process: Heat drives mantle convection currents, contributing to tectonic processes like earthquakes, volcanism, and mountain building

Earth's Internal Structure

  • Inner Core: Solid iron-nickel layer about 2,400 km wide
  • Outer Core: Liquid layer mainly composed of molten iron and nickel
  • Mantle: Hot, dense rock layer extending nearly 2,900 km
  • Crust: Thin outermost solid layer (5-8 km beneath oceans, 24-56 km beneath continents)
  • Temperature Gradient: Reaches ~3,700°C at mantle-core boundary and 5,000-6,000°C in the core

India's Geothermal Potential

Global Context

  • Global installed geothermal capacity: 15.67 GW (end of 2025)
  • Leading countries: Indonesia, United States, Philippines, Türkiye, New Zealand (account for ~67% of global capacity)

India-Specific Data

  • 381 hot springs mapped by Geological Survey of India (GSI)
  • 10 geothermal provinces identified across the country
  • Theoretical potential: ~10.6 GW
  • 42 sites recognized as promising for electricity generation and direct heat applications

Major Geothermal Provinces in India

  1. Himalayan Geothermal Province
  2. Naga-Lusai Province
  3. Andaman and Nicobar Islands
  4. Son Narmada Tapi (SONATA)
  5. West Coast
  6. Cambay Graben
  7. Aravalli
  8. Mahanadi
  9. Godavari
  10. South Indian Cratonic regions

Policy Framework

National Policy on Geothermal Energy, 2025

  • Notified by Government to establish geothermal as major pillar of India's renewable energy mix
  • Nodal Ministry: Ministry of New and Renewable Energy (MNRE)

Policy Focus Areas

  • Systematic exploration and technology development
  • Drilling and reservoir management
  • Direct-use applications
  • Ground Source Heat Pumps (GSHPs)
  • Pilot projects and Centers of Excellence
  • Development of national geothermal data repository

Private Sector Participation

  • Regulatory framework for public and private sector participation
  • Support for repurposing abandoned oil and gas wells for geothermal applications

Research and International Cooperation

  • RE-RTD Programme: Supports research institutions and industry in developing indigenous, cost-effective geothermal technologies
  • International partnerships: Australia, Iceland, and Saudi Arabia

Technological Advancements

  • Enhanced Geothermal Systems (EGS): Enables energy extraction from areas with limited conventional geothermal resources
  • Advanced Geothermal Systems (AGS): Expands geothermal exploration capabilities
  • Well Repurposing: Abandoned oil and gas wells can potentially be used for geothermal projects

Significance for India

  • Supports India's Net Zero 2070 goal
  • Provides reliable, indigenous, and sustainable clean energy
  • Reduces dependence on fossil fuels
  • First demonstration project: Puga Valley, Ladakh (commissioned by ONGC Energy Centre)
  • Complements other renewable energy sources (solar, wind)
  • Round-the-clock power generation capability