Geothermal technology has the potential to cut emissions by up to 94 per cent for cooling and 41 per cent for heating in the UK compared to other low-carbon systems.

An Imperial College London study shows that geothermal energy risks being overlooked, despite already being available and with new technology making it more attractive. This new geothermal technology, known as Aquifer Thermal Energy Storage (ATES), provides low-carbon heating and cooling by storing warm water in an underground reservoir during the summer for winter use, and cold water during the winter for summer use. Unlike conventional heat pump technologies, ATES stores and re-uses energy, rather than extracting energy from groundwater or air, making it more efficient.

The technology has already been successfully deployed, but the UK only has 11 systems in operation. These supply a tiny fraction of the UK’s heating and cooling demand (less than 0.01 per cent and 0.5 per cent, respectively) and in contrast, countries like the Netherlands have over 3,500 systems in place.

Published in the journal Applied Energy, the study analysed data from one of the ATES systems operating in London, the Wandsworth Riverside Quarter development operating in the Chalk aquifer, to assess the technology’s viability in the UK. After analysing data from 2015 to 2021, the team concluded that the system has reduced CO2 emissions by over 100 tonnes per year since its second year in operation, compared to conventional heating using natural gas.

Study leader Matt Jackson, professor of geological fluid mechanics at the Department of Earth Science and Engineering at Imperial, said: “ATES has the potential to supply around 60 per cent of the nation's current heating demand and around 80 per cent of its cooling demand. Not only does this technology offer lower CO2 emissions, it also requires less electricity than rival heat pump technologies, reducing demand on the electrical grid. The evidence shows that ATES could be suitable for widespread deployment across the UK. We have the right climatic conditions, and widespread availability of suitable aquifers in which warm and cool water can be stored. However, despite its potential and benefits, it remains almost unknown, with very few plans to expand its use.”

Despite confirming the efficient and sustainable operation of the Wandsworth ATES development in London, the team’s analysis of data from other UK ATES systems suggests some of them do not perform as well as they could. Some of the barriers to widespread deployment of the technology identified by the researchers stem from a lack of awareness and expertise regarding ATES, as well as a higher upfront cost and perceived risks associated with using a new technology.

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