Exploration of Geothermal Energy

General Studies Paper-3

Context: Geological Survey of India (GSI) has carried out exploration of geothermal energy in various recognized geothermal fields which includes collection of data on temperature, discharge, and quality/chemistry of water in different geothermal fields.

Major Highlights

• GSI has studied 381 thermally anomalous areas across India and has published a report titled ‘Geothermal Atlas of India, 2022’.
• Potential: A potential of about 10,600 MW of geothermal power has been estimated in the country.
• Projects: Singareni Collieries Company Limited (SCCL) has commissioned a 20 kW pilot geothermal power plant in Manuguru area of Bhadradri Kothagudem district in Telangana.
  • The Ministry of New and Renewable Energy (MNRE) is implementing a “Renewable Energy Research and Technology Development Programme (RE-RTD)” to develop indigenous technologies and manufacturing for widespread applications of new and renewable energy in an efficient and cost-effective manner.
  • MNRE provides up to 100% financial support to Government/non-profit research organizations and upto 70% to Industry, start-ups, private Institutes, entrepreneur, and manufacturing units under Renewable Energy Research and Technology Development Programme, including for geothermal energy R&D projects.
• Collaborations with international organisations/countries to advance geothermal energy efforts in India, include: –
  • Under the aegis of the MoU signed in 2007 between India and Iceland, both the sides have identified Geothermal as an area of cooperation.
  • India has signed an MoU with Kingdom of Saudi Arabia in 2019, wherein, Geothermal has been identified as an area of cooperation.
  • Under the Renewable Energy Technology Action Platform (RETAP) launched in 2023 between India and USA, Geothermal has been identified as a focus area.

Geothermal Energy

• Geothermal energy is a type of renewable energy that comes from the heat stored within the Earth.
• This heat is produced by the natural decay of radioactive materials and by the heat that’s left over from the planet’s formation.

Ways to Harness Geothermal Energy:

• Geothermal Power Plants: These use steam from heated water reservoirs beneath the Earth’s surface to drive turbines connected to electricity generators. There are three main types:
  • Dry Steam Plants: Directly use steam from a geothermal reservoir to turn the turbines.
  • Flash Steam Plants: Pull high-pressure hot water into lower-pressure tanks to create steam.
  • Binary Cycle Plants: Transfer heat from geothermal hot water to another liquid with a lower boiling point, which vaporizes and drives the turbine.
• Geothermal Heat Pumps: These systems use the Earth’s constant temperature to heat and cool buildings. In winter, they bring heat from the ground into buildings, and in summer, they transfer heat from buildings back into the ground.
• Direct Use Applications: Geothermal energy can also be used directly for heating buildings, growing plants in greenhouses, drying crops, and even in some industrial processes.
• Geothermal District Heating: In some areas, geothermal energy is used to provide heating for entire communities or districts through a network of pipes.
• Drawbacks: It can have some environmental impacts, such as land subsidence and the potential for induced seismicity (earthquakes triggered by human activity).
  • Geothermal resources are often location-specific, which means they are most effective in regions with significant geothermal activity, such as Iceland, parts of the United States (like California and Nevada), and the Pacific Ring of Fire.

Significance:

• Renewable and Sustainable: Geothermal energy is a renewable resource because the heat from the Earth is continually replenished.
  • Unlike fossil fuels, which are finite, geothermal energy can provide a consistent and reliable source of power and heating.
• Low Greenhouse Gas Emissions: Geothermal energy systems produce very low levels of greenhouse gases compared to fossil fuels.
  • This makes it a cleaner alternative that helps mitigate climate change and reduce air pollution.
• Diverse Applications: Beyond electricity generation, geothermal energy can be used for direct heating applications, cooling, and in various industrial processes. This versatility enhances its value as a multipurpose energy source.
• Low Operating Costs: Once a geothermal power plant or heat pump system is installed, the operational and maintenance costs are relatively low compared to other energy sources. This can result in lower long-term energy costs.
• Reduced Water Usage: Geothermal power plants generally use less water than conventional power plants, which is particularly advantageous in water-scarce regions.