IAP-25-038

Powering Net Zero from Below: The Future of Mine Water Geothermal Energy

Rising global temperatures are driving more frequent extreme weather events, rising sea levels, and widespread damage to ecosystems. In response, the UK has committed to achieving net zero carbon emissions by 2050 through the phased elimination of fossil fuels. Achieving this goal presents a particular challenge for domestic heating, which currently depends on fossil fuels for around 90% of demand.
While renewable energy sources such as wind and solar are well established, geothermal energy contributes less than 1% to the UK’s total energy supply. This under-utilisation is surprising given geothermal energy’s unique advantages: it operates continuously (24 hours a day, 365 days a year), has a small surface footprint, and is unaffected by weather or seasonal variation.
One of the most promising and underdeveloped geothermal resources in the UK is mine water geothermal energy (MWGE), which harnesses heat from the warm waters filling abandoned and flooded mine workings. With approximately 23,000 abandoned mines across the country—and around a quarter of the UK population living above them—MWGE represents a significant, distributed, and low-carbon heat source.
Several successful demonstration projects already exist, including the Gateshead mine water heating scheme, developed in collaboration with the Mine Water Heat and Energy Team from the Mining Remediation Authority (MRA, formerly the Coal Authority). However, to make a meaningful contribution to national decarbonisation targets, MWGE deployment must expand from isolated pilot schemes to a coordinated, nationwide rollout.
This PhD project will evaluate the technical, environmental, and economic feasibility of scaling up MWGE across the UK. By combining computational modelling, data analysis, and collaboration with industry partners, the research will address key challenges and opportunities for widespread implementation.

Objectives: the project integrates numerical modelling, hydrothermal analysis, and techno-economic assessment to evaluate the viability of MWGE at both local and regional scales. The research will be guided by four interlinked objectives:
1. Assessing technical feasibility – determining the potential to extract or store heat within flooded mine systems, considering geological, hydraulic, and thermal factors.
2. Quantifying scheme interactions – modelling how nearby MWGE installations might thermally or hydraulically influence one another, informing licensing and spacing strategies.
3. Evaluating economic and societal viability – estimating the cost per kilowatt-hour (kWh) of MWGE heat and examining co-benefits such as improved air quality and reduced fuel poverty.
4. Integrating MWGE into district heating – identifying opportunities to link MWGE sources with existing or planned low-carbon heat networks.
Numerical Modelling Approach:
The study will employ the recently developed GEMSToolbox (Mouli-Castillo et al., 2024), a computationally efficient software package for simulating mine water heat extraction and storage. GEMSToolbox allows for probabilistic modelling, which is particularly well suited to MWGE due to uncertainties in mine geometry, hydraulic connectivity, collapse zones, and host rock properties.By running large ensembles of simulations, the project will quantify the likelihood of successful heat extraction under varying geological conditions and operational strategies. Model outputs—such as predicted temperature changes and thermal recovery times—will help identify the most promising sites for MWGE deployment.

Thermal and Hydraulic Interaction Studies:
A crucial aspect of national MWGE rollout is understanding thermal interference between nearby systems (Sweeney et al., 2025). Using coupled groundwater and heat transport models, the student will simulate the spatial and temporal evolution of heat plumes generated by extraction and reinjection activities. These simulations will inform potential licensing frameworks to prevent resource competition and ensure long-term sustainability.

Economic and Policy Assessment:
Model results will be translated into heat supply and cost estimates. Key factors to be incorporated include:
1. Projected temperature increases for given pumping rates;
2. Local heat demand profiles and demographic data;
3. Energy price differentials (gas vs. electricity);
4. Infrastructure availability (open shafts, existing heat networks);
5. Capital and operational costs.
By integrating these datasets, the project will produce spatially resolved estimates of the cost per kWh of MWGE heat and assess how this compares to other low-carbon heating options. This work will also explore co-benefits, such as reduced air pollution, improved public health, and local job creation.

Industry Collaboration and Data Sources:
The project will be carried out in close collaboration with the Mine Water Heat and Energy Team at the Mining Remediation Authority. The MRA will provide access to mine network data, hydrogeological datasets, and operational experience from existing MWGE schemes.
A three-month internship at the MRA will allow the student to engage directly with teams working on environment, engineering, licensing, and mining information. This collaboration will provide valuable insights into regulatory and practical aspects of MWGE deployment.

Year 1

1. Conduct literature review on geothermal energy, mine hydrogeology, and low-carbon heating strategies.
2. Training in numerical modelling, Python programming, and probabilistic analysis.
3. Acquire and process mine system data in collaboration with the MRA.
4. Develop and validate initial GEMSToolbox models for representative UK mine systems

Year 2

1. Extend models to incorporate groundwater flow and heat transport between interconnected mine workings.
2. Run probabilistic simulations to quantify uncertainties and system sensitivity.
3. Present preliminary findings at national and international conferences (e.g., EGU, UK Geothermal Association).
4. Begin collaboration with Durham Energy Institute on integration of MWGE into district heating networks.

Year 3

1. Conduct regional-scale modelling to evaluate potential interference between multiple MWGE schemes.
2. Perform economic and environmental impact assessments.
3. Draft journal papers on technical and economic feasibility.
4. Undertake a three-month placement at the MRA to refine models with operational data and contribute to policy guidance.

Year 3.5

1. Finalise synthesis of technical, economic, and regulatory findings.
2. Complete thesis writing and submission.
3. Prepare final outputs, including policy briefings and public engagement materials.

The student will gain comprehensive interdisciplinary training spanning geoscience, energy systems, numerical modelling, and policy analysis. Specific skills will include:
1. Hydrogeological and geothermal system modelling using Python and GEMSToolbox;
2. Probabilistic simulation and uncertainty quantification;
3. Data processing and spatial analysis using GIS;
4. Energy economics and techno-economic evaluation;
5. Scientific writing, presentation, and outreach skills.
The student will work within a vibrant research environment in the Department of Earth Sciences, which hosts around 50 postgraduate researchers engaged in diverse Earth and environmental science topics. Close collaboration with academic staff, postdoctoral researchers, the Durham Energy Institute, and the Glasgow Center for Sustainable Energy will provide an excellent interdisciplinary framework. There will be opportunities to visit various mine water geothermal sites, such as the Gateshead Mine Water Heat Living Laboratory and the UKGEOS geoenergy observatory in Glasgow.
Participation in the IAPETUS training programme will further strengthen transferable skills such as research design, communication, and project management. The MRA internship will provide industry-relevant experience, exposure to multi-disciplinary teams, and insight into how scientific research supports real-world energy transition policy.