Geothermal: Public Perception

One key method for production of geothermal energy is the Enhanced Geothermal Systems (EGS) process, whereby fluid is inserted into fractures in the earth and heated by hot rock below the surface. This heated fluid is then used for electricity generation. Issues do however arise through the forcing of fluid into these weaknesses; new fractures can occur and existing ones can be widened which can result in induced seismicity. This issue has long been acknowledged, with Mock et al. (1997) stating that the magnitude of induced seismicity due to extraction is typically very small and does not compare to the high frequency of earthquakes that are typical for these active tectonic regions. 

However, after a series of earthquakes occurred in Basel, Switzerland in 2006 as a result of geothermal drilling, the subject has received a great deal of public concern, research and media attention. The strongest earthquake from this incident, a 3.4 magnitude earthquake, caused damage to property costing over $9 million. 

Giardino (2009) stated that the probability of creating earthquakes significant enough to be noticed on the surface is small. However, the risks still must still be considered and thorough risk analysis should be conducted before a project commences. Research into the public perception of geothermal power station safety was conducted by Carr-Cornish & Romansch (2014), who found that fewer people rejected proposals for geothermal projects when increased information and transparency were provided; however, most were happier with projects located away from settlements. This produces a key issue: an efficient geothermal plant not only generates electricity, it also provides heated water for homes and businesses, but this requires the plant to be located close to existing communities.

Mammoth Pacific Geothermal Power Station, California
Source: blm.gov

My last post outlined the huge potential of geothermal energy, however this post has looked at the risks and public concern surrounding the EGS method. Concern over induced seismicity has been heightened in a number of countries as a result of fracking, with Ellsworth (2013) stating that the increased frequency of small earthquakes in the United States, resulting from industrial activity, has raised public concern. As a result, the increased risk of these events combined with public concern could lead to difficulty gaining acceptance for new projects, despite these areas being naturally prone to earthquakes. 

As a result, not only do these new projects require careful assessment and thorough planning, they also need to account for heightened concern over industrially induced seismic activity that could play a part in the public perception of EGS. To prevent misunderstanding and backlash, strong communication and transparency will be required whilst planning future sites and proposals to ensure that this renewable resource reaches its full potential in a safe manner without harm or concern to local communities.