Energy driven piles in Australia: Design and construction lessons from a trial at Fishermans Bend

About 50% of the energy bill of buildings arises from space heating and cooling (air conditioning). The associated greenhouse gas (GHG) emissions of the sector account for between 14% and 25% (or higher, particularly overseas) of the total emissions. Geotechnical engineering designers and contractors have an opportunity to contribute to a more sustainable future. Shallow geothermal technology for efficient heating and cooling represents one such opportunity. Through a partnership between Wagstaff Pilling and The University of Melbourne, the design and construction of the first energy driven piles in Australia was undertaken in 2019, with the last field thermal performance testing completed in January 2020. These energy piles can be connected to a geothermal system.

This paper discusses the construction and installation of this small-scale field trial at Fishermans Bend (Victoria), comprising three different energy driven pile configurations. An investigation into the thermo-mechanical efficiency of driven energy piles to evaluate their capacity to provide heating and cooling for buildings is undertaken. Peer-reviewed literature already exists discussing shallow geothermal energy systems and bored energy piles. However, there is a significant gap in the literature considering driven energy piles specifically, and no public guidance about construction; thus, we aim to start redressing these issues herein. Experimental data collected by running Thermal Response Tests (TRTs) on selected energy driven piles at Fishermans Bend are presented. The information collected from the fieldwork will be used to validate detailed Finite Element Method (FEM) models and to optimise construction, minimising costs and to demonstrate none or minimal program delays.