Thermal energy system and method of operation

A method of operating a thermal energy system coupled to a building energy system which selectively provides heating and/or cooling to a building, the method comprising the steps of;

• (a) providing a thermal energy system comprising:
• a heat pump system having an output side and an input side, wherein thermal energy is received on the primary input side and thermal energy is output on the secondary output side,
• a heat energy working fluid loop extending into a building, the output side being coupled to a building by the heat energy working fluid loop to provide heating to the building from the thermal energy system,
• a first geothermal system in which a working fluid is circulated,
• a first heat exchanger between the first geothermal system and the heat energy working fluid loop, the first heat exchanger having a first input, the first input being switchably connectable to the first geothermal system, and a first output connected to the heat energy working fluid loop, wherein a first working fluid circuit is defined between the output side of the heat pump system, the first output of the first heat exchanger and the heat energy working fluid loop, and a second working fluid circuit is defined between the first input of the first heat exchanger and the first geothermal system,
• a cooling demand working fluid loop extending into the building to provide cooling to the building from the thermal energy system,
• a second geothermal system in which the working fluid is circulated,
• a second heat exchanger between the second geothermal system and the cooling demand working fluid loop, the second heat exchanger having a second input, the second input being switchably connectable to the second geothermal system, and a second output connected to the cooling demand working fluid loop, wherein the cooling demand working fluid loop defines a third working fluid circuit, and a fourth working fluid circuit is defined between the second input of the second heat exchanger and the second geothermal system,
• a first switch assembly which comprises at least one switchable plural-way valve mechanism between an output of the first geothermal system and the input side of the heat pump system and adapted selectively to direct working fluid from the first geothermal system to the first input of the first heat exchanger or to the input side of the heat pump system;
• a second switch assembly which comprises at least one switchable plural-way valve mechanism between an output of the second geothermal system and the input side of the heat pump system and adapted selectively to direct working fluid from the second geothermal system to at least one or both of the second input of the second heat exchanger or the input side of the heat pump system,
• wherein the second and fourth working fluid circuits are switchably connectable by the first and second switch assemblies and the working fluid which is circulated in the first and second geothermal systems is a common working fluid which is present in the first and second geothermal systems and on an input side of each of the heat pump system and the first and second heat exchangers;
• (b) selectively thermally connecting, by the first switch assembly, the first geothermal system to a selected one of each of (i) the input side of the heat pump system, thereby thermally connecting the first geothermal system to the heat energy working fluid loop to provide heating to the building and (ii) the first input of the first heat exchanger, thereby thermally connecting the first geothermal system to the heat energy working fluid loop to provide heating to the building;
• and
• (c) selectively thermally connecting, by the second switch assembly, the second geothermal system to a selected one of each of (i) both of the input side of the heat pump system and the second input of the second heat exchanger, thereby thermally connecting the second geothermal system and the input side of the heat pump to the cooling demand working fluid loop to provide cooling to the building and (iii) the second input of the second heat exchanger, thereby thermally connecting the second geothermal system to the cooling demand working fluid loop to provide cooling to the building.