Research highlight

Delivering geoenergy research infrastructure in Glasgow

Data from the Glasgow Observatory will help us to understand coal-mine-water heat and sustainable ways of heating our cities.

24/02/2021

Around 25 per cent of UK homes and businesses are located in the vicinity of abandoned coal mines. Sustainable mine-water energy systems using the flooded mine workings could provide decarbonised heat for significant numbers of buildings. Image: Cuningar Loop park, Glasgow. BGS © UKRI.

The Glasgow Observatory, which is part of the UK Geoenergy Observatories, is an at-scale research infrastructure comprising 12 boreholes, fenced research compounds and surface monitoring equipment for investigating shallow, low temperature, coal-mine-water heat energy, heat storage resources and environmental change. Data from the observatory will help us to understand the processes and impacts of this heat source and heat store as a sustainable way of heating homes and businesses in our cities. The observatory is a UKRI/NERC research infrastructure available for academic and commercial research access.

Annoted image of the research Compound of the Glasgow Observatory at Cuningar Loop — Site 1 Research Compound of the Glasgow Observatory at Cuningar Loop, Clyde Gateway. © BAM Nuttall (background); BGS © UKRI (inset).

Eleven of the boreholes have been constructed at Cuningar Loop, at depths of 16–94 m. Six boreholes target mine workings and are constructed with downhole electrical resistivity and fibre-optic sensors. They are designed to measure heat and water flow rates, and to facilitate testing and monitoring to form an evidence base for activities such as resource characterisation. Researchers will also have access to five environmental baseline boreholes and data from surface-based monitoring equipment to underpin environmental management from subsurface to surface.

Diagram showing hoe mine water is pumped up from underground, passed thtrough the heat exchanger and returned back to the aquifer. — Warm mine water, commonly between 10 and 25°C, is pumped to the surface from boreholes. At the surface, heat pumps extract the heat from the mine water and raise the water temperature within a domestic or industrial heating loop to 60–70 °C. The water within this separate loop can be used to heat homes and offices. The cooler mine water is returned to a different part of the mine system, where it begins its journey to be reheated. BGS © UKRI.

In addition, seismic monitoring is ongoing at the 199 m-deep observatory borehole at Dalmarnock, which also provided the cored reference section.

Diagram of the sensor setup within a singl;e borehole at the Glasgow Observatory — At the Glasgow Observatory, five seismometers are installed in a single borehole. The seismic monitoring borehole is 1.4 km from the mine water and environmental baseline boreholes at Cuningar Loop. BGS © UKRI.

Hydrogeological testing has proved significant flow rates of water at around 12°C in the mine-water boreholes. The Glasgow Observatory provides a research capability representative of small mine-heat energy schemes.

Introducing the UK Geoenergy Observatories: centres for world-class research in Glasgow and Cheshire run by BGS on behalf of the research community, NERC and UKRI. BGS © UKRI.

During drilling of the boreholes in 2019, BGS staff collected hundreds of rock and fluid samples for university researchers undertaking novel geochemical and geomicrobiological research towards resolving challenges for mine-water heat implementation . Site visits from early career researchers, PhD students and local senior school pupils provided opportunities for knowledge transfer and training in drilling for geoenergy. Once COVID-19 restrictions are lifted, sampling and access will resume. Detailed site information is now available, along with information on core, rock chip and preserved samples held by BGS.

Installation of uPVC casing, electrical resistivity tomography (ERT) and fibre-optic cable into Borehole GGA07 at the UK Geoenergy Observatory in Glasgow in December 2019. BGS © UKRI.

New, open data from the Glasgow Observatory is being released all the time, for example:

live seismic monitoring data
borehole information packs
core scan images from the 199 m borehole
geological models

Ground gas surveys, a soil chemistry survey and ground motion studies have also been released, along with ongoing monthly surface water and groundwater sample suites, all of which form an environmental baseline. The interdisciplinary, open information will grow over the 15-year observatory timespan, with researchers able to integrate their data into the unrivalled evidence base.

‘The Glasgow Observatory gives us an unprecedented look into the subsurface. New open data can be freely accessed. Researchers and commercial operators are able to use the infrastructure to reduce subsurface uncertainties and test technologies to utilise mine-water energy towards decarbonising the supply of heat.’

Dr Alison Monaghan, MBE, science lead for the UK Geoenergy Observatory in Glasgow.

Looking ahead, there are plans to install permanent infrastructure for mine-water heat abstraction and heat storage research in 2021. This is expected to comprise sealed, open-loop abstraction and re-injection, flexible ‘doublets’ on four of the mine-water boreholes, connected via pipework to a small heat centre.