[25.9.2024] Like us, our colleagues in the PUSH-IT team are conducting surveys to determine the suitability of various sites for harnessing geothermal energy. Here is a post published on Linkedin 5.9.2024 by representatives of the United Dawns partner site in Cornwall, UK. The original post can be found HERE
Why Cornwall? In today’s post we will be discussing why we chose Cornwall as the place to develop the UK’s first geothermal power plant, with an exclusive insight from our very own geologist, Amy Peach-Gibson. Our first site is at United Downs, close to Redruth in Cornwall.
We chose Cornwall because it has good geothermal potential due to the high heat producing granite that lies beneath it. Further, the United Downs also has a number of large, old fault structures, that let the hot water move through the rock.
Our Geologist, Amy, is excited by the geothermal potential of Cornwall:
“Cornwall’s unique geology makes it a prime candidate for geothermal energy development! Geothermal exploration began in Cornwall in the 1980s with the Hot Dry Rocks Project, however the presence of high temperatures and the abundance of flowing water underground were well known to the Cornish miners long before.
Most of Cornwall is underlain by a large body of granite known as the ‘Cornubian Batholith’. The granite generates and retains significant heat due to the natural decay of the radioactive elements, Potassium (K), Uranium (U) and Thorium (Th), giving much of Cornwall a high geothermal gradient (~35°c/km) and high surface heat flow.
Naturally fractured rock, or fault zones, provide highly permeable pathways for the flow of heat-carrying fluid. These faults, known by the Cornish miners as ‘Crosscourses’, enable the circulation of geothermal fluids deep within the granite and allow the heat to be carried to surface for energy production.”
Watch our YouTube video via the link below, which explains why we chose Cornwall in even more detail: VIDEO
The image below shows how Cornwall’s local surface heat flow compares to the rest of the UK. As you can see, on average the UK has a surface heat flow of 50-60mW/m2 whilst parts of Cornwall reach up to 120mW/m2. This creates a geothermal gradient which is almost 10oC per kilometre hotter than the UK average!
