Geological Heating and Cooling
Heating and cooling from the geology beneath us.
Geohac designs and develops heating and cooling from low-enthalpy geothermal resources: flooded mine workings, aquifers, borehole arrays and repurposed wells. Cooling for data centres and industry, heat for the buildings around them, and the ground itself as a seasonal store, each scheme engineered to suit its location.
The proposition
One geological resource. Cooling, heat and storage from the same ground.
Cooling
Year-round cooling from the ground
The shallow and intermediate subsurface sits at a stable temperature all year. Whether the resource is flooded mine workings, an aquifer or a closed-loop borehole array, heat exchange with it cools a data centre or industrial process with no evaporative water use and far less cooling energy than conventional chillers and cooling towers.
Heat
Rejected heat put to work
Waste heat from a data centre or process is upgraded and supplied to the buildings around it, through a fifth-generation district heating and cooling network where one fits, or by direct supply where it does not.
Storage
The ground as a seasonal thermal store
Heat that is not needed in summer is banked in the workings or aquifer and drawn down in winter, so the resource keeps pace with demand across the year rather than just the day.
The resources
Low-enthalpy geothermal, in whichever form the site provides.
Geohac is not tied to one technology. We start from the demand and the geology, and select the resource and system that fit.
Flooded mine workings
Large, interconnected water-filled voids beneath former coalfields: a high-capacity source, sink and seasonal store.
Aquifers
Open-loop abstraction and reinjection from shallow and deep sedimentary aquifers, including aquifer thermal energy storage.
Closed-loop borehole arrays
Ground-source heat exchange where no natural water body is available, sized for large heating and cooling loads.
Repurposed and purpose-drilled wells
Existing oil, gas and water wells given a second life, or new wells designed for heat, drawing directly on our well construction background.
Why geological heating and cooling
The resource is already in place. It just happens to be underground.
Former coalfields are threaded with centuries of abandoned workings. When pumping stopped, they flooded, leaving vast, interconnected, water-filled voids beneath many of the towns and industrial estates where power, fibre and land are available today. Elsewhere, sedimentary basins hold aquifers with the same steady temperature, and where neither exists a borehole array or a repurposed well reaches the same resource.
Data centres and industry need cooling every hour of the year, and the heat they reject is usually thrown away. Geohac closes that loop by matching the demand to the geology beneath it.
- 01A stable coolant
Deep mine water and aquifer water stay close to the same temperature through summer and winter, which is exactly the condition a cooling system wants.
- 02Built where the land, grid and people are
Former colliery and industrial sites are brownfield land with existing grid connections, road access and communities looking for skilled employment.
- 03Heat that would otherwise be wasted
Every unit of electricity a data centre uses becomes heat. Recovering it into a heat network turns an operating cost into a local asset.
- 04A store, not just a source
Because a mine or aquifer is a large, insulated volume, it can absorb surplus heat in summer and give it back in winter, smoothing supply against demand.
- 05Designed for the location
No two sites share the same geology or the same demand. Geohac engineers the combination of source, cooling, heat offtake and storage that suits each place, rather than one fixed template.
Where we say low-carbon, we mean heat and cooling supplied by electric pumps and heat pumps drawing on the ground, in place of gas boilers, chillers and cooling towers. The carbon saving depends on the electricity used and is assessed for each scheme.
How it works
Four layers, one integrated system.
Geohac integrates the geological resource, the cooling load, the heat offtake and renewable power as a single engineered system rather than four separate projects. The layers are modular: the example below uses flooded mine workings feeding a data centre and a district network, but the same approach is configured for a low-enthalpy aquifer, a direct heat supply or an industrial cooling load, whichever the location calls for.
Renewable power can run the system
Wind or solar generation, on site or contracted, can supply the pumps and the cooling load.
Ground water cools the load
Cool water is drawn from the flooded workings or aquifer, passed through heat exchangers at surface, and returned warm to the ground.
Waste heat is put to use
Rejected heat is supplied to the surrounding buildings, through a fifth-generation district heating and cooling network or by direct connection, as the location dictates.
The ground stores what is not needed
Surplus heat is banked in the workings or aquifer through summer and drawn down in winter, matching the resource to seasonal demand.
What we do
Two service lines, one subsurface approach.
Geohac develops geological heating and cooling schemes, and applies the same subsurface and data expertise as a digital service to clients with their own ground to understand.
Cooling and heat as a service
From first screening of a site to a running scheme, Geohac's model is to take the geological and engineering risk, so that data centre operators, industry and heat network developers can buy cooling and heat as a service.
- Site identification and screening across the full range of low-enthalpy geothermal resources
- Resource assessment: volume, temperature, connectivity and sustainable yield
- Feasibility, concept design and consenting support
- The right configuration for the location: cooling, heat offtake, storage and power
- Delivery, operation and long-term monitoring
Subsurface analysis, data science and monitoring
Geohac Digital brings the subsurface practice of the oil and gas industry to geothermal, mine water and wider ground engineering: building models of the ground, applying data science to what is measured, and turning both into decisions that can be defended.
- Geological and subsurface modelling
- Interpretation of historical records, mine plans and borehole data
- Data science and analytics applied to subsurface and operational data
- Measurement, instrumentation and long-term monitoring
- Visualisation and reporting for partners, investors and regulators
Who we work with
Built for professional engagement
Geohac works alongside the organisations that plan, consent, design and finance low-carbon infrastructure. We bring the subsurface; you bring the project.
Data centre operators and developers
Ground-based cooling as a second cooling source alongside existing plant, with a route to heat reuse for planning and ESG reporting, designed for the site. Early-stage screening through to cooling as a service.
Councils and combined authorities
Heat network zoning, local area energy plans and regeneration of former colliery and industrial land. Independent assessment of what the ground beneath a district can supply.
Engineering and planning consultancies
A specialist subsurface partner for feasibility studies, heat network design and data centre masterplans: geology, resource assessment, well design and monitoring, delivered to your programme.
Heat network developers, utilities and investors
A year-round heat source with seasonal storage in the ground, for district and direct supply, backed by resource analysis that stands up to due diligence.
About Geohac
Geological Heating and Cooling
Geohac is a UK company founded to bring the ground into service as a heating and cooling resource, from flooded coal mines and aquifers to borehole arrays and repurposed wells. The name says what we do: we use geology to move heat.
Geohac's founders come from long careers in the oil and gas industry, where understanding the subsurface is the whole job. That experience is the basis of the business: the difference between a promising idea and a bankable scheme is how well you understand the ground. We bring in specialist partners where a scheme needs them.
How we work
We treat every scheme as an integrated system and design it for its location. We are rigorous about the subsurface, conservative about what we claim, and open with partners about what the data does and does not yet show.
Where a project is confidential, it stays that way. Site-specific work is shared with the partners involved, under agreement.
Planning a data centre, a heat network or a local energy strategy?
Tell us about the site or the study. We will tell you what the ground beneath it can do, and how we would work with your team.
Contact
Talk to us about a site, a network or a partnership.
If you operate or plan a data centre, work in a council or combined authority on heat and regeneration, lead studies in an engineering consultancy, or develop and finance heat networks, we would like to hear from you. We keep contact simple: email, read by a director.
Email us
Write to the address that fits, from your work account, and tell us about the site, the study or the network. Enquiries are read by the founding directors and answered personally.
Please do not send confidential material in a first email; we will arrange a secure channel if one is needed. Only addresses ending @geohac.co.uk are ours.
More contacts
All contact addresses, including support, security and billing.