Abstract: In an embodiment, a method of operating a geothermal energy system includes selectively connecting each of a plurality of borehole heat exchangers to any other of the plurality of borehole heat exchangers thereby to permit flow of a working fluid between the borehole heat exchangers and to selectively distribute the working fluid within the plurality of borehole heat exchangers. Each borehole heat exchanger has an elongate tube having a closed bottom end and first and second adjacent elongate coaxial conduits interconnected at the bottom end, the first conduit being tubular and surrounded by the second conduit which is annular. Each borehole heat exchanger has a major portion thereof extending in a substantially inclined orientation at an angle of from 3 to 95 degrees from vertical, the borehole heat exchangers being connected to a manifold for the working fluid.

Abstract: A geothermal energy system comprising a plurality of borehole heat exchangers, each borehole heat exchanger containing a working fluid and comprising an elongate tube having a closed bottom end and first and second adjacent elongate conduits interconnected at the bottom end, a manifold for the working fluid to which the plurality of borehole heat exchangers is connected, and a plurality of valves connected between the plurality of borehole heat exchangers and the manifold, whereby the first and second conduits of the plurality of borehole heat exchangers are selectively connectable to the manifold by operation of the valves.

Abstract: A thermal energy system includes a first thermal energy system, a closed loop geothermal energy system, an intermediate heat pump thermally coupling the first thermal energy system with the geothermal energy system, and a second thermal energy system thermally connected to the geothermal energy system. The first and second thermal energy systems have opposite net thermal energy demands from the geothermal system. The geothermal energy system has first and second groups of borehole heat exchangers and each borehole heat exchanger contains a working fluid. Each borehole heat exchanger includes an elongated tube having a closed bottom end and first and second adjacent elongated conduits interconnected at the bottom end. Each group of borehole heat exchanger is selectively and alternatively connectable to the intermediate heat pump. The first thermal energy system may be a refrigeration system having condensers and the closed loop geothermal energy system may provide cooling of the condensers.

Abstract: A geothermal energy system comprising at least one borehole heat exchanger, Hie at least one borehole heat exchanger containing a working fluid and comprising an elongate tube having a closed bottom end and first and second adjacent elongate coaxial conduits interconnected at the bottom end, the first conduit being tubular and surrounded by the second conduit which is annular, the at least one borehole heat exchanger having a major portion thereof extending in a substantially inclined orientation at an angle of from 3 to 95 degrees from vertical.

Abstract: A thermal energy system comprising a first thermal system, the first thermal system in use having a heating and/or cooling demand, a closed loop geothermal energy system comprising a plurality of borehole heat exchangers, each borehole heat exchanger containing a working fluid, and an intermediate heat pump thermally connected between the first thermal system and the geothermal energy system. Each borehole heat exchanger may comprise an elongate tube having a closed bottom end and first and second adjacent elongate conduits interconnected at the bottom end. In particular, the first thermal system is a refrigeration system and the ‘closed loop geothermal energy system provides cooling of the condenser(s) of the refrigeration system.