In all the discussions about energy these days, we often forget one major source. This energy source is available literally anywhere on the planet; it doesn’t produce billowing clouds of pollutants like fossil fuels; it doesn’t result in any hazardous radioactive waste; it’s not weather dependent like solar or wind energy.
Almost seems too good to be true, doesn’t it? On some scale, people have been using it for thousands of years, and with recent advances in the required technology, we are closer than ever to tapping into this magical energy source on a large scale.
It’s not magic: it’s geothermal energy. The word itself means “earth heat,” and that’s just what it is. To date, it’s really only been used in limited locations (near tectonic plate boundaries) and on a smaller scale for home and industrial heating. But as technological advances allow, we will be seeing more and more geothermal heat being used to do everything from warming your home to powering your lights, appliances, and the outlet you plug your electric car into.
But how does it actually work? Well, despite the existence of every living thing we know about on its cold, hard surface, our planet is just like every other giant space rock – underneath the thin surface it is incredibly hot, with a core of molten iron and a thick layer of molten rock called the “mantle.” Occasionally, this heat makes its way through the surface in the form of volcanoes, undersea vents, or hot springs.
Basically, if you drill deep enough into the earth, you get to a point where it’s very hot. There is often hot water down there that you can pump to the surface, or you can pump clean surface water down and then draw it back, hot, to the surface. This hot water is useful to heat your home, your business, or, if it’s hot enough and on a large enough scale, to turn an electricity-generating turbine.
Now, geothermal energy is not quite free nor perfectly clean in terms of carbon emissions. Sometimes the hot water that is dawn up from underground has greenhouse gases dissolved in it, which can be released as the water cools. To help solve this problem, many facilities simply pump this water back into the earth. For use in home heating, there is the issue of the pumps – they take electricity to work, and depending on how clean your local electric grid is, they may account for significant carbon emissions, which can offset the use of the geothermal heat.
It’s not yet time to start drilling holes across the world, but geothermal energy is a very forward-looking energy source. With the proper technology and implementation, it could prove to be the basis for a clean, efficient future of energy consumption.
For more information on this growing industry, visit www.geoexchange.org