Shallow geothermal energy potential for heating and cooling of buildings with regeneration under climate change scenarios

• Published in: Energy (Oxford) 2022-04, Vol.244, p.123086, Article 123086
• Main Authors: Walch, Alina, Li, Xiang, Chambers, Jonathan, Mohajeri, Nahid, Yilmaz, Selin, Patel, Martin, Scartezzini, Jean-Louis
• Format: Article
• Language: English
• Subjects: Climate; Climate change; Climate change scenarios; Cooling; Cooling systems; Decision making; District heating; District heating and cooling; Energy; Energy industry; Geothermal energy; Heat exchange; Heat exchangers; Heat pumps; Heat transfer; Heat treatment; Heating; Injection; Potential estimation; Regeneration; Seasonal regeneration; Shallow geothermal energy; Space cooling (buildings)
• ISSN: 0360-5442; 1873-6785
• DOI: 10.1016/j.energy.2021.123086

Shallow ground-source heat pumps (GSHPs) are a promising technology for contributing to the decarbonisation of the energy sector. In heating-dominated climates, the combined use of GSHPs for both heating and cooling increases their technical potential, defined as the maximum energy that can be exchanged with the ground, as the re-injection of excess heat from space cooling leads to a seasonal regeneration of the ground. This paper proposes a new approach to quantify the technical potential of GSHPs, accounting for effects of seasonal regeneration, and to estimate the useful energy to supply building energy demands at regional scale. The useful energy is obtained for direct heat exchange and for district heating and cooling (DHC) under several scenarios for climate change and market penetration levels of cooling systems. The case study in western Switzerland suggests that seasonal regeneration allows for annual maximum heat extraction densities above 300 kWh/m2 at heat injection densities above 330 kWh/m2. Results also show that GSHPs may cover up to 63% of cooling and 55% of heating demand for individual GSHPs in 2050 in Switzerland, which increases to 87% and 85% if DHC is used. The regional-scale results may serve to inform decision making on strategic areas for installing GSHPs. [Display omitted] •Technical potential of shallow ground-source heat pumps (GSHPs) at regional scale.•Seasonal regeneration of GSHPs by re-injection of space cooling needs to the ground.•Useful potential for supplying building energy demand under three climate scenarios.•Impact of district heating and cooling (DHC) on the useful potential of GSHPs.•Case study in western Switzerland: Up to 87% of energy potentially supplied for DHC.