Environmental Impact Calculations, Life Cycle Cost Analysis-Article

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The paper reviews methods for assessing the sustainability of thermoactive geotechnical systems, which use building foundations as heat exchangers for ground-source heat pumps (GSHPs). These systems can reduce installation costs compared with separate borehole fields and lower heating and cooling energy use, while serving several sustainability objectives, including energy efficiency, reduced land use, and whole-life cost savings.<br /><br />Existing building and infrastructure certification schemes offer possible assessment frameworks, but environmental impacts require attention across the system’s life cycle. Direct impacts include changes to subsurface temperature, which may affect groundwater flow, soil chemistry, microorganisms, and soil strength, as well as possible leakage of circulating fluid. Current regulations for closed-loop systems are limited and often focus on system performance rather than environmental protection.<br /><br />Life Cycle Analysis (LCA) should cover materials, transport, construction, and the system’s operational and maintenance phases. Embodied carbon and embodied energy can help compare foundation designs; available studies show that materials are typically their largest contributor. Thermoactive components such as circulation tubing add relatively little to construction impacts, but the energy savings during operation may outweigh their embodied impacts. However, operational performance and long-term effects remain uncertain because case histories are scarce.<br /><br />The environmental benefits of GSHPs depend strongly on how electricity is generated. They can substantially reduce emissions where electricity comes from renewable sources, but may provide little benefit—or even increase emissions—where electricity is carbon-intensive. A monitored UK project achieved strong cooling performance and annual carbon savings, though its heating performance was less favorable and actual cooling needs exceeded predictions.<br /><br />The authors conclude that thermoactive systems have considerable sustainability potential, but robust evaluation requires standardized life-cycle methods, better environmental data, and more long-term monitoring.

Keywords

thermoactive geotechnical systems

ground-source heat pumps

sustainability assessment

life cycle analysis

embodied carbon

embodied energy

environmental impacts

closed-loop systems

building foundations

renewable electricity