United Downs Deep Geothermal Power project

The United Downs Geothermal Power project (UDDGP) is an innovative multi-partner, cross-disciplinary endeavour to explore if geothermal technology can produce commercial energy in the UK. The project will run for three years and is funded by the European Regional Development Fund (ERDF).

Researchers from geology, psychology and sociology at the University of Plymouth will undertake research relating to the public perception and communication of geothermal power, geothermal technologies and the subsurface environment. They will work in partnership with Geothermal Engineering Ltd who are installing a test geothermal well at the United Downs site in Cornwall, as well as scientists from the British Geological Survey who are installing a microseismic monitoring network.

What is happening in Cornwall?

The geothermal power being investigated in Cornwall is Enhanced Geothermal System (EGS).

  • Most traditional geothermal plants use steam from water naturally found in hot (often volcanic) rocks near the surface to drive turbines and produce electricity and heat.
  • Enhanced Geothermal (sometimes called engineered geothermal) generates energy from rocks that are either hot, but don’t have water (Deep Geothermal) or have lots of water, but are not very warm (Shallow Geothermal). 
  • The shallow type of Geothermal is most commonly seen in ground source heat pumps (GSHP) in small developments or even people’s homes and usually only generate heat – not electricity.
  • Deep Geothermal involves drilling down to where the rocks are really hot and then adding water to the high temperature system that the drilling creates. This allows the water to turn into steam, which then drives a turbine, creating electricity. Heat is also generated as a by-product.

The geothermal potential at United Downs comes from large amounts of granite that can be found very close to (sometimes at) the surface in this part of Cornwall, which has a high quantity of natural heat. 

Although the rocks are dry and have very little water in them that would provide the kind of geothermal resource available in countries like Iceland, the normal temperature of granite underground can be used to heat water introduced to the rocks by means of a shallow well (approx. 2.5km deep). 

The water is heated as it passes through a natural fracture system (the Porthtowan Fault) and returns to the surface by means of a second, deeper well (approx. 4.5km). The steam from the hot water drives a turbine at the surface that produces electricity, which can be added to the National Grid.

Public perceptions and communication

Researchers at the University of Plymouth are going to be investigating several aspects of the United Downs Deep Geothermal Power project that have specifically to do with people’s interactions with this new technology. The project will involve: 

  • Psychologists looking at how people picture the geological subsurface where the geothermal power is generated, and what emotions are involved with people connected to a geothermal power project. 
  • Sociologists will be looking at the impact of the media on communications about geothermal and using state-of-the-art eye tracking software to assess how people access and interpret any new media information. 
  • Communications specialists looking at how to improve effective communications between the companies interested in this new technology and the resident populations that will live near the potential development sites.

The team from Geothermal Engineering Limited with Professor Iain Stewart