How Does Geothermal Energy Compare?

Geothermal energy is generated using the Earth’s heat.  In some places on Earth, parts of the mantle are pushed upwards, away from the core and towards the Earth’s crust.  This causes nearby rock to melt and surrounding water to increase in temperature.  Hot springs, like the ones pictured here can result from this process.

Geothermal heat has shown to be most useful for direct heating with over 28 gigawatts produced.  This is far more efficient than converting geothermal heat into electricity and then back to heat again, because so much energy is lost in the process.  This heat is used for warming buildings in cold climate, industrial processes and desalination.  Each of those applications would use massive amounts of electricity if the heat were not provided through direct geothermal.  This is very old technology, with the earliest known use being a heated stone pool from the Qin dynasty around 300BC.



A hot spring, where the Earth’s heat escapes.


Electricity generation from geothermal heat is becoming more common as it is a clean, sustainable source of energy.  Until recently, we’ve only been able to make use of this energy from near the tectonic plate edges.  We’ve since discovered new techniques for gathering this energy from a wider range of locations making it more practical for widespread use.

There is far more than enough geothermal energy to meet all of our needs, and replace non-renewables.  The major drawback is that geothermal plants are extremely expensive to build, and many of them will not be profitable.  They are more likely to happen as government projects or at least with government subsidies at this point.  Compared to solar and wind power, geothermal is more ideal for heating and provides a more stable source of electricity as the earths heat varies less than sun coverage or wind speed.  It’s major drawbacks are cost, and limited placement options for the time being.