What's the principle behind geothermal energy extraction?

Geothermal energy extraction is based on harnessing heat from the Earth's interior to generate electricity.

Geothermal energy is a type of renewable energy that is derived from the Earth's internal heat. This heat originates from the formation of the planet, from radioactive decay of minerals, and from solar energy absorbed at the surface. The principle behind geothermal energy extraction involves tapping into this heat and using it to generate electricity.

The process begins with the identification of geothermal reservoirs, which are areas with high thermal activity. These are typically found in regions of volcanic activity, where the Earth's crust is thinner and heat from the mantle is closer to the surface. Once a suitable site is identified, a well is drilled into the ground to access the geothermal reservoir.

The heat from the Earth's interior warms up water or other fluids present in the reservoir, creating steam. This steam is then directed to the surface through pipes, where it drives turbines connected to generators. The mechanical energy of the spinning turbines is converted into electrical energy, which can then be distributed to the power grid.

There are different types of geothermal power plants, including dry steam, flash steam, and binary cycle plants. Dry steam plants use the steam directly from the reservoir to turn the turbines. Flash steam plants use high-pressure hot water from the reservoir, which is converted into steam when its pressure is reduced. Binary cycle plants use a secondary fluid with a lower boiling point than water, which is vaporised by the geothermal heat and used to turn the turbines.

Geothermal energy extraction is a sustainable and environmentally friendly method of power generation. It does not involve the burning of fossil fuels, and thus does not contribute to greenhouse gas emissions. Moreover, the heat from the Earth's interior is a virtually inexhaustible source of energy, making geothermal power a reliable and sustainable solution for our energy needs.