Geothermal in Cornwall

History of geothermal in Cornwall, the work being done today and the work of Robert Were Fox, which is still used in the industry today.

All geothermal projects rely on the correct geological subsurface, not only the rock type but also the presence of natural hot water permeating through fractured rock. We know there is an abundance of hot water underground in Cornwall from historic mining records, and it was a Cornishman - Robert Were Fox (younger) - who studied the varying heat temperatures in Cornish mines and devised the heat gradient mapping that geologists still use today.

Robert Were Fox (the younger) was Charles Fox’s brother. Chrales Fox bought Trebah Garden in 1831 and started Trebah on the journey of what it is today.

Geothermal Engineering Ltd (GEL) was founded in 2008 with the aim of developing the UK’s first geothermal power plant. Following 10 years of fundraising, the project at United Downs began by drilling two deep wells, one of which is the deepest onshore well in the UK. Despite the delays caused by the Covid-19 pandemic, the war in Ukraine and the troubles in the Red Sea, GEL has persevered and has now constructed the 1st UK geothermal power plant with power production onto the national grid expected early in 2026.

Please read this important information about events at Trebah:

Location: Please enter via the Visitor Centre. You will be directed where to go from there. The event is being held in Trebah House.

Refreshment availability: Trebah Kitchen will be open.

Garden entry: If you would like to explore the garden before or after you will need to purchase garden entry if you are a non-member.

When to arrive: Please arrive with enough time for the event to start at the advertised time.

Dogs: Assistance dogs only please.

Image credit: Stereogram of Robert Were Fox found at Penjerrick. (Edward J. Gillin, 2020.)