A detailed geological model has been compiled as part of a feasibility study including the interpretation of existing geological and historical seismic reflection data. The area around Etruria Valley was identified as being one of the most promising sites in the UK for harnessing deep geothermal heat resources.
Whilst the required geological conditions were successfully identified in the Etruria Valley, the resolution of data was insufficient to undertake the planning and design of a geothermal well. Therefore, a new survey was carried out in 2016 to obtain high resolution images of the underground from 2 new seismic reflection lines (10 Km) each cutting across the city adding to the data previously obtained.
The overall pool of data (seismic reflection lines, British Geological Survey’s geology and geophysical data, Coal Authority data, mine working) provides the highest possible level of detail to map the geothermal resevoirs at depth before undertaking drilling. It is predicted that hot water exceeding 95˚C should be located at a depth of circa 3.8km beneath Etruria Valley making Stoke-on-Trent ideally placed to support the development of a geothermal energy project.
What is Being Proposed?
In Stoke-on-Trent, geothermal energy will be harnessed by drilling into a geological formation beneath Etruria Valley using two wells that will be drilled to an approximate depth of 3,800m.
The first well will be used to abstract geothermal water from deep underground. This will then be passed through a heat exchanger in the geothermal plant, before being returned back into the ground through the second well. This phase of construction is expected to take around 170 days to complete.
An energy centre will be built underground in order to minimise the visual impact. As a result, only a head house will be visible above ground, built to provide access to the underground chamber beneath. This will house the Heat Exchanger which will play an important role in harnessing renewable heat from the geothermal water. This heat will then provide customers with their heat and hot water requirements. Construction of the head house and energy centre will take around six months to complete, with operation commencing shortly afterwards.
A programme to install a district heating network to distribute heat from the proposed plant in Stoke-on-Trent would be developed by Stoke-on Trent City Council.