Deep geothermal resources are a renewable energy source that is likely to become key to driving baseload electricity generation in a low-carbon future.
Geothermal energy doesn’t always require a volcano to be effective, some areas can have favourable geology that naturally produces its own heat and generally rocks get hotter with depth (the geothermal gradient). The geothermal gradient means that if we were to drill deep enough, hot rocks would be found to power geothermal power plants. But drilling is expensive and we want to make our electricity affordable.
In SW England, the composition of the granites means that they are hot and emit heat. This is quite a small amount of heat but with such large volumes of granite in the region, and because it is covered by sedimentary rocks, heat can build up over time. The mudstones and sandstones act as a blanket trapping heat which means that significant heat resources exist beneath our feet which enhances the geothermal gradient and means hot rocks exist closer to surface. This reduces drilling costs and means that we can use geothermal energy to generate electricity.
More will follow…