  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/m$^2$ at heat injection
densities above 330 kWh/m$^2$. Results also show that GSHPs may cover up to 55%
of heating demand while covering 57% of service-sector cooling demand for
individual GSHPs in 2050, which increases to around 85% with DHC. The
regional-scale results may serve to inform decision making on strategic areas
for installing GSHPs.
