Groundwater heat pump systems diffusion and groundwater resources protection

Geothermal Energy, being a clean and sustainable source of energy, is gaining importance worldwide due to various reasons. Geothermal power can be generated throughout the year on twenty four hour basis as it's not much dependent on ambient temperature and weather conditions. Recently there is an increased interest in exploitation of low enthalpy geothermal resources for other applications such as geothermal space heating and cooling for domestic, industrial and commercial applications.GroundWater Heat Pump systems (GWHPs) extract water from one or more wells, pass it through a heat exchanger or a heat pump, which either extracts heat from, or rejects heat, and discharge water back into the aquifer or nearby surface water.This reinjection disturbs the natural aquifer temperature, producing a local temperature anomalies (cold or heat plume) known as the thermal affected zone (TAZ).Moreover, it is important to know if the TAZ can interfere with downgradient pre-existing plants or subsurface infrastructure or with the plant itself (thermal feedback). It is then important to know, even before constructing a GWHP system, the future TAZ extent around the planned injection point.Due to these risks, the increasing number of GWHP systems enforces the need for new criteria to develop subsurface energy policies that allow planning their spatial distribution. To obtain these sustainability criteria, the results of different dedicated studies are here proposed, in order to optimize the design and operation of GWHP systems.