The thermal response of an infinite line of open loop wells for ground coupled heat pump systems

Ground thermal energy storage is a means of storing thermal energy underground during the summer and utilizing it during the winter. The main use of such a technology is in the heating, ventilating and air conditioning sector where the ground provides a stable temperature reservoir for a heat pump system. Heat pumps are mechanical systems that provide heating to a space in the winter, and cooling in the summer. They are increasingly popular because the same system provides both heating modes, depending on the direction of the cycle upon which they operate. The stable temperature reservoir allows the heat pump system to run at a higher efficiency. Thermal energy is transmitted to and from the ground by circulation of water through standing column geothermal wells. In commercial applications, the ground storage is enabled by a field of multiple wells; hence proper well spacing is important for optimum performance for a fixed land area and required storage capacity. If wells are too closely spaced, one system may thermally encroach on another thereby lowering the efficiency of both.