by Judith Willson

Created on: August 07, 2010   Last Updated: November 09, 2010

Geothermal energy is a renewable source that comes from the heat in the earth's core.  It has the potential to be one of the cleanest there is.  Unfortunately, as with all energy sources, environmental concerns have been raised about geothermal energy.  There are no renewable technologies that wreck the ecological havoc of using fossil fuels, or have the potential for disaster of nuclear power but that doesn’t mean that they can’t cause damage in their own right.

The concerns raised about geothermal energy are relatively easy to address and just require the engineering to be tweaked a little before exploitation.  Geothermal energy comes from water deep in the ground.  In the past this was utilised mainly from near tectonic fault lines.  These are the places where tectonic plates meet and the earth’s hot core is relatively exposed.  They are associated with volcanic activity. 

Technological developments are expanding the possible sites that could produce geothermal energy.  In fact it has been estimated that all the energy that the world currently uses could come from geothermal energy. The main problems from exploiting this heat source are toxins being brought to the surface, greenhouse gases being released, destruction of natural habitats and the possibility of triggering earthquakes. 

The toxins contained in the water include some that could be extremely hazardous if released into the environment.  These include mercury, which if released into surface water will build up in fish, and cause severe ecological and health problems.  The solution is simply for the water to be injected back where it came from once it has cooled and the heat energy utilised.  A closed loop system like this will cause next to no pollution, but an open loop one can cause serious problems.

This also applies to gases being released.  There are greenhouse gases trapped far beneath the surface that get released by geothermal operations.   There are ways to mitigate this through clever engineering techniques, but compared to the gases released by the exploitation of fossil fuels it is negligible anyway.

Unfortunately some of the best places to install geothermal power plants are areas of great natural beauty and biodiversity, including nature reserves.  Developments of any kind in such areas are going to cause damage, from the plants themselves and from the necessary transport infrastructure required for workers to get there.  This can be reduced with sensitive development but not entirely eliminated.

The final issue is that of inducing land instability, including the possibility of earthquakes.  Seismic activity can be triggered by any kind of deep drilling and the only answer is a thorough risk assessment before drilling begins.  The enforcement of very high safety standards is also important.  We have seen from the oil industry how prone companies are to ignore this, and getting regulations in place before very large scale exploitation of geothermal resources begins is essential.

Geothermal energy could be a very most environmentally friendly energy source.  To ensure that its exploitation doesn't cause ecological problems,  strict regulations and standards need to be set now by countries that haven’t already.  Waiting until multi-national corporations realise just how much money could be made is rather a bad idea.

Learn more about this author, Judith Willson.
Click here to send this author comments or questions.