Geothermal Energy refers to the heat energy generated and stored inside the crust of the Earth. We all know that the centre of the Earth is always at a constant temperature. This temperature is equal to the temperature of the Sun due to the consistent process of nuclear fission going on.
How is Geothermal Energy produced?
This high temperature of the centre of the Earth results in the melting of the rocks and the upward motion of the mantle. These rocks then get accumulated in the regions known as hot spots. When the underground water gets mixed with these rocks, a large amount of steam is generated.
In some cases, this steam and hot water can find an open surface and an outlet and appear on the land as hot springs. The word geothermal comes from the Greek words geo (earth) and thermal (heat). Therefore, Geothermal Energy is a renewable energy source because heat is continuously produced inside the Earth.
Geothermal Energy resource falls into three major categories:
- Geo-pressurized zones,
- Hot-rock zones
- Hydrothermal convection zones.
Types of Geothermal Energy Power plants
Geothermal Power plants are of 3 types:
- Binary cycle
- Dry steam
- Flash steam
The three types of geothermal power plants have a common thing- installing steam turbines to generate electricity.
- Dry steam geothermal power plants
These plants use dry steam to produce electricity. Dry steam refers to the water vapour present in the Earth's crust. The authorities of these power plants drill two different wells to reach a hot reservoir in the Earth’s crust. One well is named the production well, and the other is called the injection well. The production well performs the function of extracting steam at the temperature of 150°C (300°F).
- Flash steam geothermal power plants
This geothermal power plant uses water at a temperature of around 182°C (360°F). These plants use flash steam to produce electricity. Flash streaming is defined as the process of vaporizing boiling water and directing it to the turbine.
- Binary cycle geothermal power plants
These power plants are more effective than the Flash steam geothermal power plants and Dry steam geothermal power plants. This is because it uses relatively colder water (57°C (135°F) to generate electricity.
Advantages of Geothermal Energy
Major advantages of Geothermal Energy are:
- Environmentally Friendly
- Rapid Evolution
- Heating and Cooling
- Huge Potential
- Sustainable / Stable
- No Fuel Required
Disadvantages of Geothermal Energy
The most prominent disadvantages of Geothermal Energy are:
- High Costs
- Environmental Side Effects
- Location Restricted
- Workforce Required
Geothermal Energy Sites in India
The famous geothermal sites of India are Rajgir (Bihar), Manikaran (Himachal Pradesh), Surajkund (Jharkhand), and Sohana (Haryana). According to a survey, India has the potential to generate 10,000 MWe of geothermal power.
Renewable energy plays a vital role in today's life. It provides energy in four major areas. These areas include water and air heating/cooling, generation of electricity, rural (off-grid) energy services, and transportation services. Globally, humans consume approximately 20% of renewable energy.
FAQs on Geothermal Energy
Q.1. What is meant by Geothermal Energy?
Geothermal Energy is considered a renewable energy source. It refers to the heat energy generated and stored inside the crust of the Earth.
Q.2. In which industries is Geothermal Energy being applied?
Industries, where Geothermal Energy is being applied, are -
- Agriculture sector
- Gold mining
- district heating systems
- milk pasteurizing
Q.3. Name some alternative sources of energy other than Geothermal Energy.
The alternative sources of energy other than Geothermal Energy are -
- Hydroelectric Energy
- Wind Energy
- Geothermal Energy
- Tidal Power
- Solar Energy
- Biomass Energy
Q.4. Can we build Geothermal Energy Plants anywhere?
No, we cannot build Geothermal Energy Plants anywhere. Reservoirs above the temperature of 100°C are necessary to build a geothermal plant.