Exergy International, a provider of new generation Organic Rankine Cycle (ORC) power plants, and Geothermal Engineering (GEL), a UK developer and operator of geothermal plants, have signed a contract for the supply of a 3 MWe gross capacity ORC power plant at the United Downs site, in Cornwall, UK. This represents the first integrated deep geothermal project in the UK, and is anticipated to deliver by late 2024 around 3 MWe of baseload renewable electricity and up to 10 MWth of zero carbon heat for a large housing development at Langarth Garden Village, a project being developed by Cornwall Council.
The turnkey EPC contract awarded to Exergy will include the design and engineering of the ORC system, the manufacturing of the equipment and the erection of the power plant. Exergy’s technology will utilise a radial outflow turbine to produce electricity by exploiting the heat of the geothermal fluid. The condensing system chosen is air-cooled to avoid any water consumption. Being a closed loop cycle, the power plant will not release any vapour into the atmosphere and will have a small footprint and minimal visual impact.
The system will be delivered in 18 months, with commissioning of the plant expected by late 2024. Once in operation, this installation should save more than 6500 tonnes of CO2 emissions per year compared to the emissions from an equivalent conventional fossil fuel power.
Luca Pozzoni, general manager of Exergy International, commented: “The United Downs project will be a milestone in the development of the geothermal industry in the UK and will give us the valuable opportunity to contribute with our technology and expertise to kick-starting geothermal power generation in the country. Under a structured long-term agreement with GEL, we will be able to partner for the development of future geothermal initiatives to unlock Europe’s largely untapped geothermal potential and support the decarbonisation of our energy systems.”
The United Downs Deep Geothermal Power project will be the home of the first geothermal power plant in the UK. The site, located near Redruth in Cornwall, utilises heat from the granite bedrock that underlies most of Cornwall. Two deep, directional wells have successfully been drilled for the purpose; the production well to a measured depth of 5275 m – the deepest onshore well in the UK - and the injection well to 2393m. The hot geothermal fluid will be pumped to the surface, passed through the power plant to produce electricity, then returned underground via the injection well where it will percolate through the granite to be reheated.