SCBA on underground thermal energy storage (UTES) – Update

For the efficient implementation of the energy transition in the built environment, it is important to weigh the advantages and disadvantages of different heating and cooling alternatives. In policy practice, considerations around underground thermal energy storage (UTES) often focus heavily on potential subsurface risks. At present, there is no clear quantitative framework to support policy decisions on where UTES can (low or no risk) or cannot (higher risk) be applied.

At the request of the industry association Bodemenergie Nederland, CE Delft conducted a cost-benefit analysis (CBA) in 2023, outlining a comprehensive perspective on the application of both open and closed UTES systems.

This report is an update of the original 2023 report “SCBA on UTES”. This version incorporates new insights, based on real-world data from various stakeholders, particularly regarding the maintenance of closed loop ground source heat pump in residential buildings.

For this SCBA, various heating and cooling technologies were compared at the building level, evaluating direct, indirect, and external effects. These include investment costs, energy consumption, CO₂ emissions, refrigerant leakage, impact on the electricity grid, and subsurface risks.

The SCBA leads to several key conclusions:

• UTES shows the most positive SCBA outcome
• Effects such as urban heat island mitigation, noise pollution, and subsurface impact have not yet been quantified (further research is needed to monetise these effects)
• In general, considering both the quantitative and qualitative outcomes of this SCBA – and provided that local conditions are taken into account and UTES are carefully designed and managed – the potential subsurface risks are expected to be outweighed by the societal benefits for the Netherlands
• External effects play a significant role in an integrated assessment