FAQs
The initial planning applications do not include lithium extraction, but the fluid at every geothermal site will be laboratory tested to identify any chemical and metal compounds present in the fluid. A high concentration of lithium was found at United Downs, so it is likely that other sites across Cornwall will have similar concentrations.
Lithium extraction from geothermal fluid offers an exciting opportunity for Cornwall. Lithium is a vital component of batteries, large and small, which we use in our everyday lives from mobile phones to electric vehicles. Britain is currently reliant on Lithium imports from China and the USA, so the UK needs a secure source of Lithium which Cornwall could provide.
However, extracting lithium from geothermal brines is in its infancy and so far, it has only been proven using small-scale Direct Lithium Extraction (DLE) plants similar in size to a shipping container. DLE plants do not need to be located on the same site as a geothermal power plant.
GEL will use binary power plants which emit no steam, gases or smells. It can be difficult to find images of these when searching online as most conventional geothermal plants are associated with volcanic environments, where the water is so hot that a ‘Flash’ power plant is used. GEL will keep the geothermal fluid in a closed loop and reinject it, but many flash plants do not reinject the fluid, instead releasing it as steam from a large cooling tower. This steam may also contain volcanic gases, some of which smell like rotten eggs.
For a good example of a binary geothermal power plant, click here and navigate to the second image to the left, titled “CENTRALE DE GEOTHERMIE PROFONDE DE SOULTZ-SOUSFORETS”. Click on the target symbol below the title and you will see an operational binary power plant at Soultz-sous-Forêts in France.
Every geothermal binary power plant will look slightly different as they are designed for the unique geological parameters available at each site. In general, the key features will include:
- A single-story insulated building which houses the generator and turbine for power generation.
- A small set of 10m-high air cooled fans; used to recondense the working fluid after the vapour has been used to generate electricity. These fans do not produce any visual plumes of steam or any odour.
- Pipework connecting the wellheads to the plant.
- A water storage lagoon which is used during well testing and routine maintenance.
- Low-level, small-scale substation and transformer for connecting the power station to the grid.
There will be no cooling towers, no electricity pylons, no steam, and no emissions of any kind.
The drilling rig chosen will depend on availability when contracts are being issued, which will be after planning consent has been given. GEL anticipate using a rig with a maximum mast height of 48m. For comparison, the Main Spire of Truro Cathedral is 76m high and the Carn Brea Transmitter is 152m high, both are permanent structures unlike the rig.
No, Geothermal is not the same as Fracking. The concept proven at United Downs relies on circulating water through natural fractures in the rock to generate low-carbon, renewable energy. This is not the same as fracking, where a large volume of fluid with a complex chemical composition is injected at extremely high pressures to create new fractures in intact rock, to drain the oil or gas from the reservoir.
Geothermal power projects simply circulate fresh water in pre-existing fractures and, once the heat has been used at the surface, the fluid is reinjected into the same formation to re-heat.
Development of a new site has five key stages:
- Planning the site and achieving the relevant permissions
- Preparing the site for drilling
- Drilling two deep wells
- Testing each well
- Power plant construction and commissioning
Cornwall has a long history of heavy industry and is proud of its visible mining heritage. Throughout Cornwall, derelict engine houses can be seen inland and on cliff tops from a great distance. The engine houses vary in size, but they tower above the ground with a stack or chimney up to 30m high. A geothermal power plant will be a fraction of this height, can be painted to camouflage the main structures and screened with native trees and shrubs. GEL are keen to ensure power plants do not detract from the existing vista that is peppered with the relics of past industry.
GEL will always strive to bring benefits to the local communities in both the short and long term. These include:
- A Community Fund of at least £40,000 per site shared between sustainable, cohesive community projects in the local parishes.
- More than £1.5million per project is put directly into the local economy through local business engagement.
- A dedicated community manager will keep the public informed about the project progress and report back on concerns or issues to the GEL team to ensure an open dialogue is maintained.
- An education and careers Programme for schools across Cornwall provides engaging resources and talks as well as careers advice from primary school to university.
- GEL will increase every site’s biodiversity by more than 10%
- Direct and indirect green jobs will be created in Cornwall.
Shallow water boreholes will not be impacted by deep geothermal developments. Geothermal wells are targeting reservoirs hosted in natural fracture zones at more than 4km below the Earth’s surface, unlike water boreholes which target shallow groundwater at 50 – 80m below the surface.
No, GEL does not hold the mineral rights for new sites because geothermal fluid is not regulated in the same way as minerals and metals in the UK. Once a site has confirmed planning permission for geothermal power development, GEL will open discussions with the appropriate mineral rights holders to ensure any relevant activity has been agreed.