GS 3: Infrastructure: Energy
Context: India is exploring geothermal energy as a reliable source of renewable power to strengthen energy security, reduce dependence on fossil fuels, and achieve its Net Zero target by 2070.
The recent inauguration of India’s deepest geothermal wells in Puga Valley, Ladakh, marks an important step towards harnessing this untapped energy resource.
What is Geothermal Energy?
- Geothermal energy is a renewable source of energy that utilizes the heat stored beneath the Earth’s surface to generate electricity and provide direct heating.
- The word “Geothermal” is derived from two Greek words:
- Geo = Earth
- Thermal = Heat
- Unlike solar and wind energy, geothermal energy can provide continuous power throughout the year.
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Sources of Earth’s Internal Heat
The Earth’s internal heat mainly originates from two sources.
Residual Heat
- Residual heat is the heat that has remained trapped inside the Earth since its formation nearly 4.5 billion years ago.
- This primordial heat continues to exist within the Earth’s interior.
Radioactive Decay
- Radioactive elements such as Uranium and Thorium, present in the Earth’s crust and mantle, continuously undergo natural decay.
- This decay releases heat, which contributes significantly to the Earth’s internal thermal energy.
How is Geothermal Energy Generated?
The process involves the following steps:
- Deep wells are drilled into geothermal reservoirs beneath the Earth’s surface.
- Hot water or steam trapped underground is brought to the surface.
- The high-pressure steam rotates a turbine connected to a generator.
- The generator converts mechanical energy into electricity.
- After cooling, the water is re-injected into the reservoir to maintain sustainability.
India’s Geothermal Initiative in Puga Valley
Recent Development
- The Lieutenant Governor of Ladakh inaugurated India’s deepest geothermal wells at Puga Valley.
- The project has been undertaken by ONGC Energy Centre.
Key Features
- Two geothermal wells have been drilled.
- The planned drilling depth is 1,000 metres.
- The project is located at an altitude of approximately 14,000 feet.
- At nearly 400 metres, temperatures of around 135°C have already been recorded.
- The project is a 1 MW pilot project intended to demonstrate commercial feasibility.
Significance of the Puga Valley Project
- It will serve as a blueprint for future geothermal projects in India.
- It will support Ladakh’s Carbon Neutral Development Strategy.
- It will reduce dependence on diesel-based electricity generation in remote Himalayan regions.
- It will promote clean and reliable energy in ecologically fragile areas.
- It will strengthen India’s renewable energy portfolio.
Why is Puga Valley Suitable for Geothermal Energy?
Location
- Puga Valley is located in the Leh district of Ladakh within the Changthang region.
Geological Importance
- It forms part of the Himalayan Geothermal Belt.
- The collision between the Indian Plate and the Eurasian Plate created favourable geothermal conditions.
- The Earth’s crust is relatively thinner in this region.
- Hot magma lies closer to the Earth’s surface.
Evidence of Active Geothermal Activity
The region contains:
- Fumaroles (steam vents)
- Hot springs
- Mud pools
- Sulphur deposits
These features indicate the presence of an active geothermal system.
Advantages of Geothermal Energy
- Continuous Power Supply: Geothermal energy provides 24×7 baseload power, unlike solar and wind energy.
- Renewable and Clean Energy: It is a renewable source with very low greenhouse gas emissions.
- Energy Security
- It reduces dependence on imported fossil fuels.
- It improves energy independence.
- Multiple Applications: Apart from electricity generation, geothermal energy can be used for:
- Space heating
- Greenhouse farming
- Aquaculture
- Industrial heating
- District heating systems
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Iceland: A Global Success Story
- Iceland transformed its energy sector after the 1970s oil crisis by investing heavily in geothermal resources.
- Around 65% of its primary energy comes from geothermal sources.
- Nearly 90% of homes are heated using geothermal energy.
- Iceland demonstrates how political commitment and geographical advantages can create a sustainable energy system.
Global Status of Geothermal Energy
- Global installed geothermal capacity exceeds 17 GW.
- Geothermal energy contributes less than 1% of global electricity generation.
- Major producers include:
- United States
- Indonesia
- Philippines
Geothermal Energy Potential in India
According to the Geological Survey of India (GSI) Geothermal Atlas (2022):
- India possesses an estimated 10,600 MW geothermal energy potential.
- Around 381 potential geothermal sites have been identified across the country.
India’s First Operational Geothermal Plant
- India’s first operational geothermal pilot plant has been established by Singareni Collieries Company Limited (SCCL) at Manuguru, Telangana.
- It has a capacity of 20 kW.
Organic Rankine Cycle (ORC)
- The Organic Rankine Cycle (ORC) is a technology used when geothermal water is not hot enough to produce steam directly.
- Heat from geothermal water is transferred to another fluid having a lower boiling point.
- The secondary fluid vaporizes and drives the turbine to generate electricity.
Challenges in Developing Geothermal Energy
- High Initial Investment: Deep drilling requires substantial capital investment.
- Geological Uncertainty: There is no guarantee that commercially viable geothermal reservoirs will be discovered after drilling.
- Technological Constraints: India has limited expertise in deep drilling technologies.
- Limited Resource Exploration: Advanced 3D geothermal surveys are still inadequate.
- Remote Locations: Most geothermal resources are located in difficult mountainous regions, increasing logistical costs.
- Policy Vacuum: India does not yet have a dedicated National Geothermal Energy Policy.
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Way Forward
- Formulate a National Geothermal Policy: India should introduce a comprehensive policy with financial incentives, tax benefits, and subsidies.
- Promote Public-Private Partnerships (PPP): Collaboration between the government and private sector should be encouraged.
- International Cooperation: India should strengthen technology partnerships with countries such as Iceland and the United States.
- Scale up Pilot Projects: Successful pilot projects should be expanded into commercial-scale power plants.
- Grid Integration: Geothermal power should be integrated as baseload renewable energy within the national grid.
- Increase Research and Development: Institutions such as GSI and ONGC Energy Centre should receive greater funding for research and advanced exploration.