Field Studies on the Application and Performance of Geothermal Energy Piles (GEP) in Buildings: An Overview

In recent years, the escalating global energy demand, coupled with the imperative to address climate change, have underscored the urgency of transitioning to energy from renewable sources. Geothermal energy piles (GEPs) are one of such renewable sources of energy that utilizes low heat within the shallow depths of the ground for heating or cooling buildings. The use of GEP systems in buildings to regulate indoor temperatures has proven to be economical and environmentally friendly. Despite the surge in adoption of this sustainable technology over the last two decades, a holistic understanding of the long-term performance and thermo-mechanical behaviour of GEPs is still at its early stages and therefore has been a subject of interest to researchers. This paper provides an overview of field studies on the application of GEPs and their performance with regards to heat exchange efficiency and thermo-mechanical behavior. Based on literatures, it was observed that the long-term seasonal heating coefficient was quite high resulting in a seasonal energy reduction compared to conventional air-conditioning. Also, the magnitude of induced strains and stresses is influenced by the restraints at the ends of the pile and the properties of the surrounding soil, while thermal loading had little impact on side friction. Moreover, the thermal axial strains fall within acceptable ranges, suggesting a minimal risk of structural failure. Thus, it was concluded that when appropriately designed and accurately installed, the GEP system operates as an efficient alternative energy source that benefits the environment. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.