Geothermal energy definition

In order to define geothermal energy let us first take a look at the word „geothermal“. This word has its root in Greek language, and comes from the two Greek words: „geo“meaning earth, and „thermos“meaning heat. The simplest translation of the word geothermal would therefore be „earth's heat“, and this could do for the most basic definition of geothermal energy. However, the more appropriate definition of geothermal energy would be „thermal energy that is generated and stored in the Earth's core. Furthermore, we also need to know that this thermal energy in Earth's core has its origin in radioactive decay of minerals inside the Earth's core.

Geothermal energy is much cleaner source of energy than fossil fuels (oil, coal and natural gas) in terms of greenhouse gas emissions. Geothermal wells release very negligible amount of greenhouse gases trapped deep within the earth's core when compared to amount of greenhouse gases released by the fossil fuel fired power stations.

What about the potential of geothermal energy? Geothermal energy has abundant potential as there is enough heat inside the Earth's core to more than satisfy current global energy demand. The only problem with harnessing geothermal energy is that the very little of totally available geothermal energy resources are being harnessed. The limits in currently available geothermal technologies make geothermal energy projects viable only in areas near the tectonic boundaries.

The use of geothermal energy still isn't widespread with geothermal power plants operating in only 24 countries across the world. United States is the global geothermal leader with total geothermal capacity of more than 3000 MW coming from its 77 geothermal power stations.

The most famous, and also the largest geothermal power plant complex in the world, is located in Geysers, California. Even despite being global geothermal energy leader United States generates only around 0.3% of its total electricity from geothermal power plants.

Geothermal energy can be used not just to generate electricity but also for heating purposes. Geothermal heating is in fact, a more efficient and also more profitable way of harnessing geothermal energy as compared to geothermal electricity generation.

Geothermal energy, unlike solar and wind, doesn't require energy storage solution, since it is available 24-7, all days in the year. It also has minimal water requirements. The bad side is high capital costs, mostly due to the drilling.

Geothermal energy should play much bigger role in global energy market. The industry is certainly in need of technological and scientific advances, which should help bring capital costs of new geothermal projects down, making geothermal power affordable to much more countries, all over the world. 

The potential is certainly there, and now it's up to science and industry to turn this potential into useful form of energy, whether for electricity generation or heating/cooling purposes.