UK’s first deep geothermal energy plant in 37 years begins operations

Eden project’s deep geothermal heating plant, located in Cornwall, began operations on Monday, June 19.

The plant consists of a single well, constructed from May to October 2021, and drilled by means of conventional mud rotary drilling to a vertical depth of 4,871 meters and a total length of 5,277 meters into granite.

Inside the well, the upper 3,860 meters were laid with insulated vacuum tube in the middle of the well that transports hot water to a plate heat exchanger on top. The plate head extracts heat from the water and circulates it into Eden’s heating circuits to be used, while sending cold water back into the well, through the outer sections, to be reheated.

In the time between the well’s construction end and the beginning of operations, well testing took place regarding permeability and production capacity. Furthermore, well testing was conducted in phases between January 2022 and November 2022, while it was interrupted for a week on March 9 of 2022 as a 1.7 induced seismic event was experienced.

The project’s beginning of operations marks a significant milestone in the UK’s energy production, as it is the country’s first deep geothermal plant since 1986.

Finally, the project received £24 million funding from the European Regional Development Fund, Cornwall Council and Gravis Capital Management.