Geothermal energy, in the simplest terms, is the energy derived from the heat inside the earth. It is contained in the rocks and fluids beneath the earth’s crust and can be found as far down as its hot molten rock, Magma.
The core constantly produces heat due to radioactive decay, and so it is a renewable resource.
The Ins and Outs of the Resource
It is usually utilised in two ways, directly drilling into the earth or from hot springs on the surface.
Equipment is dug at places where the Magma reaches the surface, forming pockets. So the critical factor in harnessing geothermal energy is controlling the high pressure of heated water. Iceland, a prosperous economy, meets most of its energy requirements through geothermal energy.
Indonesia is home to three of the ten most giant thermal power plants installations globally, followed by the US and Philippines with two each.
While Iceland has a collection of blazing underground volcanoes, Indonesia is in the ‘ring of fire’, i.e. at a confluence of tectonic plates.
How Is It Set Up?
While setting up a geothermal plant, the first process is to analyse where pockets of water heated by mantle (1000⁰C-35000⁰C) are, then drilling is done several km into porous rock.
Here the hot and high-pressure groundwater flows into the well, and the rapid change in pressure and temperature converts it to steam.
This steam turns turbines, thereby producing electricity by the principle of electromagnetic induction through generators.
This steam is cycled in a loop so that there is no wastage. Geothermal energy can be used as a leading source of power and a substitute for electricity for heating purposes during winters depending on the geographical parameters of the region.
Advantages Over Other Sources
The main advantage of geothermal energy over any other renewable resource is its minuscule carbon emission and study system. It also preserves forests because a balance of the environment is necessary for it.
The reliability of electric power generated from geothermal energy can sustain in the long term. Transport of resources is also not an issue as it requires only mobile transportation pipelines within a short distance.
It is also available throughout the year as the productivity of geothermal resources is relatively unaffected by climate change.
Another feature is that it has industry potential to grow and help deal with situations like heating water at fish farms, drying crops etc.
The effectiveness of geothermal energy is also unparalleled as the heat pumps used for heating and cooling buildings are ranked among the best systems obtainable today.
Consequences
All these benefits being counted, there are inevitable consequences too. The first concern is installing these plants, which can be around $ 20 million, a one-time investment but a significant amount to consider.
Solar panels require semiconductors like Selenium and Germanium, which are rare; their price will only increase with demand.
Geothermal plant costs might only decrease with the introduction of better materials. Another argument is that the drilling done several kilometres in the recesses of the earth releases gases like Hydrogen sulfide and methane, which are harmful.
Drilling can also cause disturbances in the surface and may lead to earthquakes if overused. Such a situation can be avoided by proper electromagnetic monitoring and management.
Current State and Future Possibilities
We have six geothermal plants in India, Manikaran in Himachal Pradesh and Surajkund in Jharkhand being the most promising ones. In these plants, geothermal energy is produced at an experimentative level, far from its potential.
The good news is that with major companies like Tata Power and Geosyndicate planning their involvement in the field, it may soon find its requisite place and significantly reduce the dependence on fossil fuels.
Geothermal energy, once established, is the best resource but may take a while to get used to it; some problems might arise.
Areas of faulted blocks in the Aravali Hills and the volcanic Arc in Andaman and Nicobar Island should be considered possible centres of our following geothermal plants.
“The new energy economy harnesses the energy in the wind, the energy coming from the sun and heat from within the earth itself” – Lester R Brown.
