Ground energy systems: delivering the potential

Ground energy systems are increasingly being considered as an alternative to traditional heating and cooling systems as a way to reduce carbon emissions, control energy costs and improve the environmental performance of buildings. These systems use the ground and groundwater beneath a site as a heat source or sink, interacting through boreholes or pipes that exchange heat with the ground. This paper reviews the principles underpinning the systems and describes the two main types of system (open loop and closed loop). Four potential barriers to wider scale application of ground energy systems are highlighted. These are thermal interference between neighbouring systems in densely developed urban areas, increasing environmental regulation of below-ground elements, capital cost and the need to ensure that systems are sustainable in the long term. If the full potential of ground energy systems is to be realised, it is important that input from geotechnical and geological specialists is used to ensure that the below-ground elements are designed using appropriate design tools and site-specific data. It is also important that appropriate post-occupancy monitoring is in place to provide feedback to designers on the long-term performance of these systems.