Aquifer Thermal Energy Storage: Challenges to Widespread Uptake in the United Kingdom and Other Immature Markets

Aquifer Thermal Energy Storage (ATES) can provide low carbon, seasonal heating and cooling. Waste heat is captured in the summer and stored as warm water via boreholes in an underground aquifer to provide heating in winter; conversely, waste cool is captured in winter and stored as cool water to provide cooling in summer. The warm water temperature is typically increased for heating and the cool water temperature may be decreased for cooling using a heat pump. Storage aquifers are typically shallow (ca. 10s to 100s m) and used for other purposes such as potable water supply. Unlike conventional geothermal, the capture and storage of waste heat and cool in an ATES system allows sustainable energy provision.

ATES uptake is dominated by The Netherlands, approaching 3000 installations. The UK has a seasonal climate, and many major cities are underlain by suitable storage aquifers, such as the Chalk beneath London and the Permo-Triassic sandstones beneath Liverpool and Manchester. Moreover, cooling is becoming increasingly important as the climate heats, especially in London and the south-east, which recently recorded all-time-high day and night-time temperatures.

Despite these favourable climatic and subsurface characteristics, uptake of ATES in the UK remains low with just 11 installations over the past 16 years supplying ca. 12 MW as compared to national demand of ca. 50 GW. This presentation reports the first findings of a cross-disciplinary study to identify and overcome barriers to widespread uptake of ATES in the UK and other immature markets. Research to date includes identification and performance analysis of UK ATES systems, mapping of UK suitability for ATES, laboratory and field experiments and numerical modelling to de-risk the response of key UK aquifers, and stakeholder engagement including industry, regulatory bodies, local and national policy makers, and the general public.

Findings to date show that the operational principles of ATES are not well understood in the UK leading to some failures of early deployments. Monitoring data are sparse and often not fit-for-purpose, and classification of installations by the regulator is inconsistent. Uncertainty in aquifer response over different time horizons is perceived to be a major risk. ATES has a very low profile and is often not considered at the planning stage.