System and method for providing domestic hot water and/or space heating within a building, and a removable cover of a storage vessel

A system for providing domestic hot water and/or space heating within a building, comprising:

• a) at least one storage vessel comprising a removable cover, wherein an internal volume of the at least one storage vessel is fluidly connected to a source of sewage and/or wastewater from one or more buildings,
• b) a water-source heat pump,
• c) at least one solar thermal collector,
• d) at least one heat transfer circuit, wherein the at least one heat transfer circuit comprises at least one fluid line containing a heat transfer fluid,
• e) a controller for controlling an operation of the system,
• wherein the system comprises an operation mode in which the controller of the system is configured to connect the at least one solar thermal collector to the at least one storage vessel via the at least one fluid line, wherein the system is configured to store a heat output from the at least one solar thermal collector in sewage and/or wastewater present in the internal volume of the at least one storage vessel.