The United Downs Deep Geothermal Power Project, Cornwall, UK

Abstract

The United Downs Deep Geothermal Power (UDDGP) project is the first geothermal power project in the United Kingdom. It aims to develop the geothermal resources in the heat-producing granites that lie beneath Cornwall in SW England. Financial support has come from the European Regional Development Fund and the local authority (Cornwall Council) who, together, have provided £13m of the £18m project budget. The project consists of two deviated wells drilled to intersect a target fault structure that is hoped will provide sufficient permeability to support circulation of between 20 and 60l/s. The production well will intersect the fault at a depth of 4,500m where the temperature is expected to be 190OC. The injection well will be 2,500m deep and the target for electricity production from the demonstration power plant is 1-3MWe. The objective of the project is to prove the concept of operating a system with a very large well spacing, within an organized natural fracture system, and to demonstrate the viability of producing electricity so that the necessary private investment can be attracted to further develop the geothermal resources in Cornwall. Funding agreements were signed in June 2017 and, following a period of contract procurement and site preparation, drilling started in November 2018. This paper places the project in the context of previous geothermal research carried out in Cornwall, summarises the UDDGP concept and reports drilling and testing results. It also outlines the microsesimic and noise monitoring programmes implemented to protect the local community and describes the associated public outreach, education and research initiatives.