What is geothermal energy?

Hint:The interior of Earth consists of three distinct regions – Crust, Mantle, Outer Core, and Inner Core. The temperature in these regions increases to very higher amounts as one goes down towards the core.



Complete step by step answer:
The geothermal energy is defined as the heat within the Earth. The word geothermal is a combination of two Greek words, geo meaning earth and thermal meaning heat.
The source of the Earth’s interior heat is the thermal energy generated from radioactive decay and the continuous loss of heat from the Earth’s interior. The temperatures at the mantle-core boundary can reach up to a value of ${4000^ \circ }C$. The huge temperature causes the rock to melt and the solid mantle behaves plastically. This causes the heat to move upward in a convective process up to the lower crust. The approximate temperature of the rock and water in the lower crust is about ${400^ \circ }C$.
Geothermal power is cost-efficient, reliable, sustainable, and renewable which opens up a new scope for using it as an alternate source of energy as opposed to conventional sources of energy such as fossil fuels. However, the main disadvantage is that the energy source has been limited to tectonic plate boundaries.
There are two forms in which geothermal energy can be tapped from the earth’s interior – Vapor-dominated and Liquid-dominated forms. Liquid-dominated reservoirs (LDRs) are more common with temperatures greater than 200 °C (392 °F) and are found near young volcanoes surrounding the Pacific Ocean and in rift zones and hot spots. Flash plants are the common way to generate electricity from these sources.

Note: The most natural forms of geothermal energy are hot springs. One of the most famous among them is in the Yellowstone National Park in Wyoming, USA, which is widely known for its huge geothermal features.