What is geothermal energy
Geothermal energy is heat from the earth. Below the surface there is a practically limitless store of thermal energy which can be used to generate electricity and supply heat. Geothermal energy is usually associated with volcanic regions or tectonic plate boundaries where there are very high temperatures close to the surface. But improvements in drilling and power plant technology now make it possible to consider geothermal as a viable option in other places too.
Is geothermal energy a renewable resource
Yes, it is both renewable and sustainable. Further, unlike wind and solar, it operates all day, every day. It is already used in many countries to provide clean, natural and reliable energy with low or zero emissions (depending on the type of power plant). The heat taken out of a geothermal reservoir over its operating life would in time be replenished by the natural heat flow from the Earth.
What are the environmental impacts
The main environmental impact relates to drilling the wells at the beginning. There are potential visual and noise impacts, and there has to be road transportation of the drilling rig to and from the site. Once in operation however, geothermal energy is a very clean form of electricity production, with minimal or zero carbon emissions (depending on the type of power plant), low visual impact and small land use. There are no adverse impacts from transportation, combustion or mining of fuel, because no fuel is required.
Is geothermal 'fracking'
Fracking is associated with the production of hydrocarbons (oil or gas), whereas geothermal is a renewable energy source. Fracking aims to create large new fractures in otherwise intact rocks by fluid injections at very high flow rates and pressures, whereas harnessing geothermal energy uses pre-existing natural fractures. Fracking uses fluids with complex chemical compositions, whereas geothermal uses water. Finally, fracking risks contamination of water supplies from frac fluids and hydrocarbons. These are not present in geothermal projects and there is therefore no contamination risk.
Noise impacts of drilling
Drilling deep wells requires 24/7 operations. Usually for a period of four months. At our sites we always place a high emphasis on prevention and mitigation of potential noise problems. In addition, we choose rigs designed for urban areas and place acoustic barriers within and around the site to further reduce the risk of noise causing a disturbance.