Open-loop ground source heat pumps and groundwater systems : a literature review of current applications, regulations and problems

This report presents a literature study that was carried out to collect data and information required for developing a strategy to assess the suitability and sustainability of UK aquifers for (open-loop) GSHP installations. Developing such a strategy requires a good hydrogeological understanding but also a good knowledge of what GSHP systems are currently in use, how they are used, what problems are associated with their use and how they are regulated. Once this is understood, a methodology can be devised that assesses the suitability of an aquifer/location for GSHP installations and considers its sustainable use. Considering the complexity of influencing factors and processes, this is likely to include the use of numerical models and/or data management tools, such as GIS. This report collects and summarizes the information available in the contemporary literature on open-loop ground source heat pump (GSHP) applications. Chapter 1 provides a brief introduction and background information on the subject. In Chapter 2, information on the general use of open-loop GSHP technology within the UK are gathered together with statistics on the number of installations and capacities. Chapter 3 gives specific examples of schemes that are currently in operation in the UK and worldwide. Where available, this includes system-specific data such as abstraction rates, thermal capacities and information on the system’s design. Chapter 4 summarizes available information and data on the costeffectiveness of GSHP installations while Chapter 5 discusses potential problems associated with the running of such schemes. Chapter 6 is concerned with the regulation of GSHP systems. It gives a brief outline of existing regulatory approaches as currently employed within different European countries as well as the US. Finally Chapter 7 examines existing modelling approaches that have been used to investigate how GSHP schemes impact on the source aquifer. The chapter also reviews GIS-based tools that evaluate the suitability and sustainability of an aquifer for GSHP installations.