A Geothermal Introduction

Unlike the other categories, geothermal may be the most mysterious in its application. So… here are some of the basics.

Geothermal energy comes from the Greek words “geo” = Earth & “therme” = heat. The term “Earth heat” describes the energy released from the Earth as both warmth and power.

Great. But how does it get to be useable? How does it get from the core to the surface? The answer is simple: conduction & convection.

Conduction occurs when the heat flows out from the core and transfers onto the cooler, adjacent mantle (a layer of rock). As the heat reaches the surface of the mantle, some of the rock gets too hot and becomes magma, slowly rising (convection) with the heat from the Earth’s core. The heat then either heats up pools of rainwater formed below ground (known as geothermal reservoirs) or erupts from cracks in the surface as geysers or hot springs.


Source: Geothermal Energy Association

These methods of heat transfer have been harvested by humans dating back 10,000 years ago to Native Americans using them for medicine and cooking, while later on Romans for baths and heating buildings. Ever since the early 1900s, engineers and scientists have been drilling production wells, or wells tapping into the geothermal pockets of water. When the hot water and/or steam rises to the surface, it can be used to push turbines that in turn generate electricity. Once the water has passed the turbine, it is much cooler and the cooler water returns to the reservoir by an injection well, which stabilizes the pressure, reheats the water, and sustains the reservoir.


Source: EPA

What are some of the advantages of geothermal energy? Here’s a list:

  • Clean. They do not burn fuels to produce power.
  • Easy on the land. Geothermal power plants are the smallest per mega-watt of any power plants.
  • Reliable. They are designed to run 24-hrs per day, everyday; resistant to weather, natural disasters, etc.
  • Flexible. They are modular (unit-based design) and can expand as electricity demands increase.
  • Helps developing countries grow. These benefits can help developing nations progress without pollution and can provide power to off-grid locations.


Source: Wikipedia

And what about some of the byproducts? You may be familiar with some:

  • Balneology = to study of soothe aching muscles in hot springs and spas.
  • Agriculture. It helps produce flowers, vegetables, and other crops in greenhouses (places like Iceland, for instance).
  • Aquaculture. It reduces the amount of time to maturity for fish, shrimp, alligators, and abalone.
  • Industrial Uses. It can pasteurize milk, dry onions & lumber, and wash wool.
  • Space Heating. It can heat buildings or entire districts (like heated sidewalks or hot-water heaters).

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Sources: AnglersEbaumsworldThink Geoenergy

So when all is said and done, isn’t geothermal tons of fun?!

The uses of geothermal power are the gifts of Earth’s core. As we begin transitioning into more of its applications, I imagine quite a different world – a world that is more relaxed, more at ease, more in tune with the Earth and her powers, and more loving as a result.

Featured Image Source: Smithsonian

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