Controlling of a thermal energy distribution system

A method for controlling a district thermal energy distribution system, the district thermal energy distribution system comprising:

• a distribution grid for a liquid based distribution of heating and cooling, the distribution grid comprising a hot conduit configured to allow heat transfer liquid of a first temperature to flow therethrough and a cold conduit configured to allow heat transfer liquid of a second temperature to flow therethrough, the second temperature is lower than the first temperature, wherein the distribution grid is configured to interconnect a plurality of buildings within a city that implements the district thermal energy distribution system enabling the liquid based distribution of the heating and cooling throughout the plurality of buildings;
• a control server;
• and
• a plurality of reversible heat pump assemblies connected to the distribution grid, wherein the plurality of reversible heat pump assemblies are distributed throughout the plurality of buildings, and wherein each reversible heat pump assembly comprises:
• a heat pump having a first side and a second side, the heat pump being configured to transfer heat from the first side to the second side or vice versa, the heat pump being configured to allow heat transfer liquid from the distribution grid to flow through the first side, and to allow heat transfer liquid of either one or more local heating circuits or one or more local cooling circuits to flow through the second side,
• wherein the reversible heat pump assembly is configured to be selectively set in either a heating mode or a cooling mode,
• wherein in the heating mode:
• heat transfer liquid is allowed to flow from the hot conduit of the distribution grid through the first side and to the cold conduit of the distribution grid, and
• the heat pump is configured to transfer heat from the first side to the second side,
• wherein in the cooling mode:
• heat transfer liquid is allowed to flow from the cold conduit of the distribution grid through the first side and to the hot conduit of the distribution grid, and
• the heat pump is configured to transfer heat from the second side to the first side, and
• a heat pump assembly mode controller configured to set the reversible heat pump assembly in either the heating mode or the cooling mode;
• wherein the method comprises:
• determining, at the control server, a first set of the plurality of reversible heat pump assemblies to be set in the heating mode during a future time period;
• determining, at the control server, a second set of the plurality of reversible heat pump assemblies to be set in the cooling mode during the future time period, wherein the second set of the plurality of reversible heat pump assemblies is separate from the first set of the plurality of reversible heat pump assemblies;
• sending, from the control server to the heat pump assembly mode controllers of the reversible heat pump assemblies of the first set of the plurality of reversible heat pump assemblies, a respective control message to set the respective reversible heat pump assembly in the heating mode for the future time period;
• sending, from the control server to the heat pump assembly mode controllers of the reversible heat pump assemblies of the second set of the plurality of reversible heat pump assemblies, a respective control message to set the respective reversible heat pump assembly in the cooling mode for the future time period;
• and
• setting, by the respective heat pump assembly mode controller and in response to receiving the respective control message, the respective reversible heat pump assembly in either the heating mode or the cooling mode for the future time period.