Geothermal electricity is electrical energy generated by harnessing the power contained in the earth’s internal heat. Geothermal power is widely used in the world, and geothermal electricity is looked at by many as one of the most sustainable, environmentally-friendly forms of electricity available to us. Although not currently feasible for all locations, many people believe that in places where geothermal electricity can be generated, it could replace the bulk of energy currently created by fossil fuels, and offer an alternative to other alternative energy sources.
There are a handful of renewable energy sources currently receiving a great deal of attention as the world tries to find a replacement for the fossil fuels that it has depended on to drive the Industrial Revolution and the growth of the modern age. Solar power, hydro power, bio fuels, wind power, and tidal power are some of the most popular. All have their share of problems; however, solar panels are quite toxic to make and can only be used where there is ample sun energy, hydro power can cause serious problems with rivers, bio fuels may rob the world of needed food supplies, wind power can disrupt the pathways of migratory birds, and tidal power may damage aquatic ecosystems. While geothermal electricity is not ideal either, many people believe that it offers the greatest benefits with the least negative impact.
The earth contains a functionally-limitless reservoir of heat coming up from the core, and geothermal electricity taps into that source. Geothermal wells are created to tap into that source, and while these wells may temporarily need to recover their heat, they can do so indefinitely so long as our power use remains within a few orders of magnitude of what it is currently at. A number of fields have been sustainably running generating geothermal electricity since the early- and mid-20th century, giving real-world evidence that the energy source does seem to last for some time.
In addition to its sustainability, geothermal electricity also requires relatively little land use for the power generated. While a coal power plant requires around 20 acres to generate a single Megawatt of energy, and a nuclear power plant requires between 5 and 10 acres for a Megawatt, a geothermal power plant requires only between 1 and 8 acres for a Megawatt. Geothermal power plants are also incredibly scalable, so that a tiny remote site can get geothermal electricity through a very small generator, while a metropolis can get all of their geothermal electricity through a massive plant.
Worldwide, total energy consumption is around 16 Terawatts, and about 85% of that is generated by fossil fuels. Around 10 Gigawatts of electricity are currently generated by geothermal power, but this is distributed quite differently throughout the world. Many countries are just beginning to use geothermal energy to create electricity or supply heat, but those that have been doing it for some time often meet a great deal of their energy needs exclusively through geothermal sources. Iceland, for example, meets more than one-quarter of its total electricity demands with geothermal electricity, and there are plans to increase this number greatly in the coming years, with the ultimate goal of eliminating the use of fossil fuels in that country entirely.