Researchers working at the UK Geoenergy Observatory in Cheshire have shown that distributed acoustic sensing (DAS) has the potential to detect subsurface temperature change during geothermal experiments. The research, which was conducted by scientists from the University of Leeds as part of the NERC-funded SmartRes project (grant number NE/X005496/1), used a high-resolution, fibre-optic DAS sensing system installed in boreholes at the Cheshire Observatory.

During two days of surveying in June 2025, over 1000 seismic impacts were made at the ground surface using a controlled seismic energy source. The energy generated by these impacts — essentially sound waves propagating through the ground — was recorded by DAS in the 5km fibre-optic network installed in the observatory 100m-deep boreholes. Strong seismic arrivals were visible at all depths, validating the survey set-up and providing an encouraging seismic baseline for future thermal testing. During subsequent tests, researchers will measure whether any variations in the arrival time of sound waves can be detected, as this could indicate where heat is moving in the subsurface.

DAS sensing has proven its credentials in many subsurface settings, but is yet to be widely developed for monitoring shallow geothermal operations. Initial analysis of the data recorded in Cheshire confirms the potential of this technology to provide high-resolution monitoring of the aquifer. This will contribute to wider understanding of geothermal processes and help with the design of efficient heating systems that use geothermal energy. The measurements are one of several datasets that provide a baseline for the acoustic, electrical and thermal properties of the Sherwood Sandstone Group.

It been very exciting to undertake the first DAS survey at the Cheshire Observatory. Fibre-optic technologies like DAS are giving us unprecedented insight into many subsurface processes. For geothermal applications, the insight is really timely: we need to demonstrate to prospective stakeholders that we understand how subsurface properties will evolve under various heating scenarios.

Prof Adam Booth, associate professor of applied geophysics at the University of Leeds.

The UK Geoenergy Observatories have been designed to advance our understanding of energy storage in shallow geological systems. This cutting-edge research undertaken by the team at the University of Leeds is an excellent demonstration of the potential for these facilities to deliver on that promise.

Dr Mike Spence, science and operations lead at BGS for the Cheshire Observatory.

The UK Geoenergy Observatories are a network of custom-built facilities operated by BGS that were designed to enable research in shallow geothermal energy and underground thermal energy storage. The facilities are available to the UK science community for research, innovation and training activities.

For further information, including details on how to access the sites, please visit .

More information

Understanding how heat moves within the subsurface is important for the development of geothermal energy, including ground-source heat pumps. Determining which geological areas are suitable for their installation is vital. For the first time, scientists at BGS have used time-series data at the , which is run by BGS, to look at long-term trends for subsurface heat.

The geo-observatory monitors 62 boreholes, 49 of which were observed every 30 minutes for four years between 2014 to 2018. The analysed data found previously undetected, localised cracks in the geology in the south of the city, where the subsurface is largely clay at that depth. These newly discovered cracks, which can be caused by plant roots, provide pathways that act as recharge routes underneath the south of Cardiff, allowing rain water to enter and be conveyed to the groundwater below.

While a ground-source heat pump can be highly efficient, installing one in one of these newly discovered areas of cracks could lead to performance issues. Specifically, the constant influx of cooler groundwater could hinder the heat pump’s ability to extract heat effectively and the system could potentially affect the groundwater flow and quality.

For geothermal developers looking to install shallow ground-source heat pumps underneath the capital, it’s important that this new data is carefully considered. The research shows that installing a ground-source heat pump in Cardiff deeper than 8 m will help to maximise the technology efficiency. 

Using time-system data for the first time in Cardiff has provided vital information to further our understanding of what lies beneath our feet. The discovery of geological recharge pockets in an area where they were previously not thought to occur is an important consideration for future infrastructure projects. It essential that geothermal developers take this research into account before installing a shallow ground-source heat pump, to ensure it runs as effectively as possible and is not impacted by recharge.

Ashley Patton, engineering geologist at BGS and research lead.

For more information about the Cardiff Urban Geo-Observatory please email 51ÁÔÆæ Cardiff (bgswales@bgs.ac.uk).

The exist to enable research into the key questions that remain about minewater geothermal, from size and sustainability to environmental impacts. On 7 August 2024, Ms Gillian Martin MSP, the Scottish government Acting Cabinet Secretary for Net Zero and Energy, visited the UK Geoenergy Observatory in Glasgow, where she learned about the role BGS plays in supporting understanding of geothermal potential, engaged in a comprehensive dialogue on geothermal opportunities in Scotland, and toured the observatory facilities.

Welcomed by Dr Alison Monaghan, head of BGS Geothermal, and Vanessa Starcher, science and operations lead for the observatory, Ms Martin had the opportunity to observe the observatory boreholes and heat centre. Their conversation highlighted the minimal surface footprint of geothermal infrastructure, the reliability of constant temperatures supplied by geothermal energy and the importance of open environmental monitoring data.

Research hub

The Glasgow Observatory is a hub for both academic and commercial research, supporting innovations in mine water heat and underground thermal storage. The extensive monitoring systems in place are revealing intriguing new insights on heat movement underground, enhancing our understanding of how to optimise minewater energy for heat decarbonisation.

The observatory facilities provide a unique platform for researchers and innovators to harness and expand upon these findings and there will be exciting opportunities in the near future to join a consortium to address the uncertainties associated with this energy source. This will build upon the successful that was completed in June 2024, which provided useful insights into topics including heat loss along pipework and different modelling scenarios for geothermal schemes.

White Paper

The discussions with Ms Martin extended beyond the observatory gates to broader considerations of the challenges and solutions related to the deployment of geothermal energy in the UK. The recent and , jointly authored by BGS and Arup, provided a basis for discussions on government incentives, the evidence for a fall in capital costs and drilling risk as more geothermal schemes are developed, and the impact of current relative costs of electricity.

Wealth of opportunities

Scotland and the UK diverse geological landscape presents a wealth of opportunities for shallow and deep geothermal projects, using a range of proven technologies. The role of BGS in this energy transition is to provide underpinning, impartial, national datasets and information. Recent releases, such as the and maps of , are just a few examples of BGS contributions to advancing geothermal energy in this country.

As we move towards a greener future, the insights and data gathered through the UK Geoenergy Observatories will be critical in supporting geothermal energy to become a key component of sustainable energy policy.

For those interested in utilising the observatory for research and innovation, please .

We are delighted to announce that construction has been completed on the Cheshire Observatory, the final part of the UK Geoenergy Observatories network. The facility is now open for research activities.

The Observatory, located in the University of Chester Thornton Science Park, provides scientists with at-scale test facilities that can be used to optimise and de-risk subsurface energy storage systems and geothermal heat in an aquifer setting.

Research at the Observatories will help unlock the potential of geothermal energy to decarbonise the heating and cooling of homes and businesses, which together account for over a quarter of UK CO₂ emissions.

The Observatory is part of the UK Geoenergy Observatories network, a £31 million investment from the UK Government to deliver essential new data from the subsurface to build knowledge on clean energy. The network also includes an observatory in Glasgow, a data portal and a core scanning facility.

The Cheshire Observatory is available to the whole of the UK science community for research, innovation and training activities. Research studies funded through any source are welcome, including outside 51ÁÔÆæ and industry-led research. To find out more about the UK Geoenergy Observatories, visit or contact ukgeosenquiries@bgs.ac.uk.

The UK Geoenergy Observatory in Glasgow can be used to explore the use of low-temperature geothermal energy using flooded, abandoned mine workings. The observatory enables experimental investigation of heat and fluid flow in mine water systems using boreholes, advanced monitoring and sensors, and a flexible geothermal infrastructure for heating, cooling and thermal storage. There is a global opportunity for mine water geothermal to support the net zero agenda on the decarbonisation of heat.

On 26 and 27 April 2023, the BGS team at the observatory will be running four half-day sessions; each session will offer a comprehensive tour of the Glasgow Observatory and an opportunity for you to network and meet members of the project team and technical experts. Refreshments will also be provided.

These open events are aimed at earth scientists, sensor developers, heat engineers and commercial enterprises that are seeking opportunities to use the facility. Further information, including open access data, reports and updates on observatory development are available on the .

Due to limited capacity, we reserve the right to restrict number of places allocated to each organisation to ensure as wide a representation as possible. Spaces are limited so .

The UK need for sustainable, self-produced energy has become increasingly obvious in recent months. We have made great strides towards decarbonising our electricity supplies, taking advantage of wind, solar and tidal resources. This has built on the country net zero targets, which have been in place since 2019 and commit the UK to bring all greenhouse gas emissions to net zero by 2050.

The £31 million UK Geoenergy Observatories project led by BGS focuses on heat energy from beneath the ground. It comprises two underground observatories that will shine a light on the subsurface potential to provide homes and businesses with geothermal energy.

The Cheshire Observatory is under construction and will cover a range of geoenergy technologies, including shallow aquifer geothermal and heat storage. The Glasgow Observatory, which is operational and already producing data on mine water energy, is an at-scale research facility that is now home to a pioneering multidisciplinary collaboration.

Establishing a detailed baseline

Data was being collected from the Glasgow Observatory even before its 12 boreholes were drilled. Researchers across Scotland and the rest of the UK have been collecting data from the site, including samples of soil collected at the surface, data from the hundreds of borehole sensors and water from within the mines themselves. Collection of a wide range of geological and environmental data before and during geothermal activities is one factor that makes the site unique, says BGS Dr Alison Monaghan, and an exceptional asset to researchers and the energy industry.

The multidisciplinary approach to establishing the baseline has created ’time zero’ datasets and acted as a catalyst for new monitoring methods.

We now have a level of detail about a formerly coal mined, urban environment that doesn’t exist elsewhere. One of the main barriers to geothermal is data and places to confidently enable research for widespread, cost-effective deployment of the technology. That exactly what is available through the UK Geoenergy Observatories project.

We need to characterise the environment at ‘time zero’ to measure and understand any changes with geothermal activities. We also need novel monitoring tools for cost-effective and environmentally sound geothermal operations.

51ÁÔÆæ has made time zero soil chemistry, ground gas, surface water and groundwater characterisation, ground motion and seismic monitoring data openly accessible. This includes seasonal and temporal variability.

Additionally, over 500 water, rock and gas samples collected during the observatory construction were distributed to university researchers for carbon, isotopic and microbiological analysis. These give new insights into rock-water-gas-microbiological interactions in the subsurface and their significance for shallow geothermal heat and storage in flooded abandoned mine workings.

Dr Alison Monaghan, BGS Principal Geologist.

A ‘rare opportunity’ for early access

Dr Ryan Pereira and Dr Julia de Rezende are both based at the Lyell Centre in Edinburgh, which is a partnership between BGS and Heriot-Watt University. They recently contributed to an and say gaining access to the Glasgow Observatory was critical.

We need to understand whether there are unintended consequences from changing the water flow in the subsurface. It could, for example, stimulate microbial activity that could generate greenhouse gases and cause damage to infrastructure, which of course we don’t want. BGS had the foresight to offer early access to researchers, which gave us the chance to be more experimental.

We used an instrument that rare in the UK called a liquid chromatography-organic carbon detection-organic nitrogen detector (LC-OCD-OND). This set-up can quantify and resolve organic compound groups by molecular size, which is good because it allows us to explore food sources for microbes that may produce greenhouse gases.

The Glasgow Observatory offers a platform for finding a way forward for us to use former mine workings as a low-carbon option for heating and cooling our cities. This fundamental research is how we take forward the deployment of geothermal in the UK, of that I am certain.

Dr Ryan Pereira, the Lyell Centre.

This was a rare opportunity because, when samples are recovered from sites, the preservation methods to consider microbiology are not always a priority.

The research is still in its infancy, but we discovered the potential for increased leaching, which promotes the production of carbon dioxide and methane by microbes. Now we need to observe this under ambient conditions as the site is under trial for heating and cooling applications.

Dr Julia de Rezende, the Lyell Centre.

‘This wouldn’t be available at a commercial site’

Strathclyde University Dr Neil Burnside research interests lie in hydrogeology, geochemistry and geothermal development. He contributed to the time zero study by examining sulphur isotope values in the mine water. Dr Burnside points out that data availability was instrumental in the new findings.

It was commonly believed that sulphur isotopes should reflect water-rock interaction with source sulphide materials. However, we found highly variable, often elevated values that suggest the influence of other factors in flooded mine systems.

Instead of access to mine workings at one or two points, there a borehole array fitted with state-of-the-art sensors and many more data sources besides. This wouldn’t be available at a commercial site; it points to how unique the Glasgow Observatory is, and the opportunities it presents for research.

Dr Neil Burnside, Strathclyde University.

Open for scientists

The UK Geoenergy Observatories project provides open-source data online and the BGS team want more scientists and innovators to use the site.

There is huge scope for flexible research at the Glasgow and Cheshire observatories and, as our recent study shows, for interdisciplinary working. Work undertaken here will address key research challenges for geothermal technologies, such as planning and construction risks, resource sustainability and regulation, operational maintenance and monitoring.

The UK Geoenergy Observatories are available for researchers to inform the evidence base and develop lower-cost techniques and fit-for-purpose monitoring approaches. Glasgow is online now and Cheshire will be operational in 2024.

There is a huge opportunity for geoscientists and others to advance the cost and risk reductions necessary for mine water heat and heat storage to form an important component in decarbonising heating of our buildings towards net zero greenhouse gas emissions.

Dr Alison Monaghan.

51ÁÔÆæ scientists are joining more than 1000 participants in the European Geothermal Congress in October in Berlin, to discuss how the geothermal sector can help provide answers to the energy crisis and highlight research being undertaken in the UK.

The event brings together the geothermal community to discuss innovations, research and development, with opportunities for networking.

Presentations and research papers will be delivered by:

• Dr Corinna Abesser, BGS Head of Geothermal Energy Research
• Dr Alison Monaghan, BGS Principal Geologist
• David Boon, BGS Senior Engineering and Geothermal Geologist

Geothermal energy is the heat generated and stored in the ground and is a source of low-carbon, renewable energy. It is homegrown, available throughout the UK at depths from a few metres to several kilometres and can provide heat or power all year long. It is not dependent on weather conditions and can deliver baseload energy for balancing more intermittent power generation from renewable sources, like solar or wind.

Despite this, geothermal technologies currently deliver less than 0.3 per cent of the UK annual heat demand, using only a fraction of the estimated available geothermal heat resource.

Dr Abesser recently undertook a position with the Parliamentary Office of Science and Technology (POST), which produces impartial, peer-reviewed briefings designed to make scientific research accessible to UK Parliament.

In her , Dr Abesser says that bespoke regulatory systems, licensing and management are urgently needed, along with Government support, to develop the UK geothermal sector.

Some stakeholders argue that the absence of long-term targets and policies that support the development of skills, supply chains and a service industry are one of the main reasons why geothermal energy in the UK has fallen behind that of other, similar countries.

Lack of information regarding the application of geothermal technologies in the UK has also meant that deep geothermal is not currently factored into the UK carbon budget or Government strategies. Rollout may require long-term Government support to develop pilot projects and expand the industry.

Dr Corinna Abesser, BGS Head of Geothermal Energy Research.

There is currently no bespoke regulatory system for the licensing, ownership or management of the geothermal resource in the UK. Instead, activities are controlled under regulations originally developed for petroleum exploration or water resource use and protection.

Streamlining the regulatory process is regarded by some in the industry as an important measure to facilitate the wider uptake of geothermal technologies, for example by assigning a geothermal regulator or agency to coordinate the approval process. This could reduce costs to projects and speed up delivery.

There is a consensus among geothermal stakeholder groups that a ‘route to market’ is needed for the geothermal sector to develop in the UK. Alongside improved regulation, building a successful market framework for geothermal development might be achieved by adopting strategies similar to those provided to other sectors, such as offshore wind.

Dr Corinna Abesser.

51ÁÔÆæ is working in partnership with The Coal Authority to explore the potential of recovering heat from naturally warmed water in disused coal mines, collaborating on research and development to help scale up the delivery of mine water heat in a sustainable way, whilst also delivering net zero carbon and levelling up outcomes for coalfield communities.  

One such initiative delivered by BGS is the , an at-scale, flexible research infrastructure designed to investigate shallow, low-temperature mine-water heat energy and potential heat storage resources. The observatory complements existing and planned mine-water heat supply schemes, offering a unique capability for understanding how to balance our need for energy resources with keeping people safe, and providing evidence for environmental protection. 

The Coal Authority is speaking with a number of local authorities and organisations across Great Britain to help mine-water heat become a working, sustainable, low-carbon heat source for many more homes and businesses located above former coal mines. This work has already facilitated the construction of the first large-scale mine-water heat network in Gateshead.

51ÁÔÆæ is also collecting data from the natural groundwater system below the city of Cardiff, using a network of 61 boreholes equipped with temperature and water-level sensors, to build up a picture of the groundwater temperatures in the aquifer found just ten metres below the ground surface.

A study of the data collected between 2015 and 2018 indicates that the large heat resources stored in the UK underground water systems could sustain ‘shallow open-loop ground-source heat pump systems’, which are a low-carbon heating approach widely used in other European cities.

The European Geothermal Congress is organised by the  (EGEC), in cooperation with the German Geothermal Association.  

More information

• 51ÁÔÆæ briefing paper: Who owns geothermal heat?
• UK Geoenergy Observatories:
• Cardiff Urban Geo Observatory: Untapped heat source beneath UK streets could pave the way for greener towns and cities
• 51ÁÔÆæ Geothermal podcast: Geothermal energy with Corinna Abesser, David Boon and Gareth Farr

The team has launched a new exhibition at Glasgow Science Centre.

The is one of two new facilities that will help shed light on how underground heat resources could warm our homes and businesses.

The exhibition is called Clean Energy Beneath Our Feet and is on display now in Glasgow Science Centre Powering the Future zone.

Visitors can learn about how resources below the ground have powered our homes, towns and industries in the past, and what coming up in the future.

The exhibition was created by Glasgow Science Centre for the UK Geoenergy Observatories project.

The has 12 boreholes that are collecting data and acting as laboratories so that we can understand whether the warm water in abandoned mines could be used to power Glasgow or other cities. It was commissioned by UK Research and Innovation (51ÁÔÆæ) Natural Environment Research Council (NERC) and was delivered by BGS, which runs the site and manages its data. A second observatory is proposed in .

If we’re going to reach our net zero goals by 2050, we need a huge supply of clean energy.

This interactive exhibition examines just that and shows the major role that the subsurface will come to play in our future.

Visitors can interact with the science and technology that will shape energy in the future, touch a rock sample we took from 137 m below the surface of Glasgow and learn about the world-class science that taking place at the Glasgow geoenergy observatory in the east end.

Alison Robinson, NERC Deputy Executive Chair.

The new exhibition will be of interest to anyone keen to find out more about the use of geoenergy.

We designed it with the UK Geoenergy Observatories team so that it can travel to other science centres, museums and festivals in the UK, but for now it on show at Glasgow Science Centre.

Robin Hoyle, director of science at Glasgow Science Centre.

The Glasgow Observatory is part of a £31 million investment by the UK government through the Department for Business, Energy & Industrial Strategy (BEIS).

Find out more about the Glasgow Observatory by taking a .