As the world's countries vie for the power source that will replace oil, many eyes are watching developments in geothermal heating. While seen as a great solution, many still wonder how sustainable it truly is.

What is geothermal heating?

Far beneath the outer crust of the earth lies ground that grows hotter and hotter as it approaches the molten core. This constant heat is harvested by pipes, where it flows through them much in the same way the current HVAC systems work. Many see it as a great contender for the next power source as it has a measured 300% efficiency.

Why is it seen as a good resource?

The main aspect keeping it in the public eye is the fact that it is always going. While wind farms and solar panels rely heavily on the weather, geothermal heat is always present, meaning mining facilities can simply turn their equipment on and off as energy needs change. Another reason is that it is accessible at every point on earth because the inner molten core radiates heat outward.

Why is its sustainability in question?

The reason for this is that the heat does get used up over time. Imagine a lake, for instance. During the summer, the water gets lower and lower as the heat evaporates what's there. It isn't until the sun gives way to the rainy season that the water levels return. Should there be less water than before, the lake levels will rise but never rise to what they once were. Over time, the lake will eventually disappear altogether. This is what happens with the geothermal heat albeit on a much faster timescale. Once production ceases, heat levels jump back up but never reach the levels they were initially at.

Is it sustainable?

Studies show an affirmative so long as certain regulations are met. These include the initial heat and fluid content and their regeneration rates, in addition to the rate of heat and fluid extraction. Basically, so long as we aren't taking up heat faster than the earth can produce it, the method is sustainable. Unfortunately, as humanity has shown time and time again, we are incapable of such regulation.

At the moment, geothermal energy is proving to be very tempting as a sustainable resource, so long as we continue harvesting it with care. If we don't, there's no telling what harm we will cause when pockets of warm earth are depleted.

Informational Credit to East Side Ventilation Ltd.