Introduction
With India moving towards a cleaner tomorrow, the search for cleaner and renewable energy becomes stronger. Amongst them, geothermal energy in India is making its mark slowly. Though still under-explored compared to solar and wind energy, geothermal energy has tremendous potential, particularly from areas of tectonic activities and hot springs. This article explores the types of geothermal energy, how it is being used to generate electricity, its working model, and the advantages and disadvantages of geothermal energy. Understanding this resource can be a key to attaining diversification in India’s energy mix.
What is Geothermal Energy?
Geothermal energy can be defined as the energy that is inside of the earth. This heat energy is operational in some areas under the surface of the earth and its exploitation is used in most aspects such as generation of electricity, heating, and in industries. Geothermal energy is renewable and environment friendly unlike fossil energy. It is a source of heat caused by the radioactive decay of materials and the remaining heat of the planet formation.
Geothermal Energy in India
Despite the availability of geothermal resources, geothermal energy in India remains largely untapped. However, India has more than 350 geothermal hot springs spread across different regions. The Ministry of New and Renewable Energy (MNRE) has identified key geothermal provinces such as:
- Puga Valley in Ladakh
- Tattapani in Chhattisgarh
- Manikaran in Himachal Pradesh
- Bakreshwar in West Bengal
- Tapoban in Uttarakhand
The geothermal energy working model in these areas primarily revolves around pilot projects and research studies. And a case in point would be the Puga Valley project- one of the most promising endeavors of India which seeks to exploit high temperature geothermal reservoirs to generate power.’
Types of Geothermal Energy
There are mainly three types of geothermal energy systems, classified based on temperature and usage:
1. Dry Steam Plants: This is the earliest and the simplest type in which steam, which is located underground, directly drives the turbines to produce electricity.
2. Flash Steam Plants: The hot water of the geothermal reservoirs is flash cooled into steam that is subsequently used in rotating turbines.
3. Binary Cycle Power Plants: In this case geothermal water is used to heat up a secondary fluid that can boil at a temperature lower than that of water. With this secondary fluid, the vapor acts as a driving force to the turbine.
Each of these types of geothermal energy systems is suitable for different geological and environmental conditions.
How is Geothermal Energy Used to Produce Electricity?
One of the primary questions in the clean energy sector is: how is geothermal energy used to produce electricity? The process may be divided into the following steps:
- Optimization of Resources: Harness geothermal reservoirs using geological survey and drillings.
- Drilling: Drill to tap underground hot water or steam.
- Extraction: Pull steam or hot water to the surface. Conversion: convert the steam or heat into movement of turbines which are linked to electricity generators.
- R-re-injection: Put that cooled water back to the earth in order to keep pressure and sustainability.
This system forms the backbone of the geothermal energy working model currently being developed in India and other parts of the world.
Geothermal Energy Working Model
A geothermal energy working model provides a blueprint for setting up a functional geothermal power system. It typically includes the following components:
- Production Well: Brings hot fluid to the surface.
- Heat Exchanger or Separator: Transfers heat to a secondary fluid or separates steam from water.
- Turbine & Generator: Converts thermal energy into mechanical and then electrical energy.
- Cooling System: Cools the working fluid or steam post-use.
- Injection Well: Reintroduces used water back into the reservoir.
To illustrate the principle of geothermal electricity generation, simple models may be built around heated water, turbines and pressure chambers, to demonstrate geothermal electricity generation to demonstrate to demonstrators and for academic reasons. The models will particularly come in handy in learning about the use of geothermal energy to generate electricity.
Uses of Geothermal Energy in India
Currently, the practical uses of geothermal energy in India are limited to:
- Direct Heating: Hot springs are utilized in bathing, cooking and medical-therapeutic reasons.
- Agricultural Applications: Controlled greenhouse heating, aquaculture, and soil warming.
- Power Generation: Although it is in pilot phases in some areas such as Puga and Tattapani.
- District Heating Systems: It is proposed in colder areas to be used by residential and institutional use.
These applications can significantly be extended with the appropriate investment to industrial heating, air-conditioning systems and desalination.
Advantages and Disadvantages of Geothermal Energy
Understanding the advantages and disadvantages of geothermal energy is key to evaluating its potential role in India’s energy ecosystem.
Advantages of Geothermal Energy
- Sustainable And Renewable: Geothermal energy is continuously produced within the earth making it a sustainable energy option.
- Environmentally Friendly: It provides few or no green house gases as opposed to fossil fuels.
- Consistent and reliable: In comparison to solar and wind, geothermal energy can be used anytime of the day and at all times regardless of inclement weather.
- Low operating costs: Maintenance and operational costs are low once it is set up.
- Space Efficient: Geothermal plants despite their size have smaller footprint when compared to other energy plants.
Disadvantages of Geothermal Energy
- High Start-Assets: The process of exploration and drilling is not only costly but it also demands a huge investment.
- Geographic Limitations: It is only viable where there is a large geothermal activity.
- Depletion Risk: Unless controlled effectively, the reservoirs can lose either heat or pressure.
- Environmental Risks: Risks associated with the release of toxic fumes such as gases like hydrogen sulfur; land subsidence due to the extraction of the fluids.
- Poor Publicity: In India, awareness and policy support are low and therefore inhibiting growth.
Despite these disadvantages, the advantages and disadvantages of geothermal energy tilt in favor of developing it as a long-term clean energy resource.
Future of Geothermal Energy in India
The Indian government is slowly recognizing the untapped potential of geothermal resources. Policy support, R&D initiatives, and international collaborations are expected to improve the landscape for geothermal energy in India. According to MNRE’s roadmap, the aim is to develop at least 1 GW of geothermal power capacity in the coming decades.
Private sector investment and academic partnerships will also play a vital role in building infrastructure, training personnel, and improving the efficiency of the geothermal energy working model. If successful, India can join countries like the USA, Iceland, and the Philippines in generating clean power from the Earth’s core.
Conclusion
As India seeks to diversify its energy mix and reduce its carbon footprint, geothermal energy in India offers an eco-friendly and reliable solution. Geothermal is very promising in the country, even though at its zygotic stage, with high potentials existing in parts prone to tectonic and volcanic activities. With a clear understanding of the types of geothermal energy, the geothermal energy working model, and how geothermal energy is used to produce electricity, stakeholders can make informed decisions about investment and implementation.
The road ahead will require overcoming the advantages and disadvantages of geothermal energy, improving public awareness, and strengthening policy frameworks. With the proper combination of science, policy, and investment, geothermal energy would become one of the foundations of the green future of India.
Frequently Asked Questions (FAQs)
Geothermal energy in India refers to the heat energy stored beneath the Earth’s surface, especially in regions like Puga Valley, Tattapani, and Manikaran. Although still underdeveloped, India has over 350 geothermal hot springs that indicate a strong potential for geothermal power generation.
There are three primary types of geothermal energy systems:
Dry Steam Plants: Use natural steam from geothermal reservoirs.
Flash Steam Plants: Convert high-pressure hot water into steam.
Binary Cycle Plants: Use a secondary fluid with a low boiling point to generate power.
Geothermal energy is used to produce electricity by drilling wells into geothermal reservoirs to extract steam or hot water. This steam spins a turbine connected to a generator, producing electricity. The cooled water is then reinjected into the ground to maintain sustainability.
The geothermal energy working model includes drilling into Earth’s crust, extracting heat (in the form of steam or hot water), converting it into electricity through turbines, and re-injecting the used water back into the reservoir. This cycle is sustainable and eco-friendly.
