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

TL;DR

This study introduces a new method to assess the energy potential of shallow geothermal systems for heating and cooling, considering seasonal ground regeneration and climate change impacts, with regional case studies in Switzerland.

Contribution

It proposes a novel approach to quantify the technical potential of GSHPs, incorporating seasonal ground regeneration effects and regional climate change scenarios.

Findings

Seasonal regeneration enables high heat extraction densities.

GSHPs could meet up to 55% of heating demand in 2050.

GSHPs could supply 57-85% of cooling demand with district heating and cooling.

Abstract

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.