The present invention relates to an energy management system for a building, comprising at least one heat pump, at least one first thermal energy storage device for providing domestic hot water, at least one second thermal energy storage device for providing space heating, at least one renewable energy generation device, at least one first state of charge analyser for determining the state of charge of the at least one first thermal energy storage device, at least one second state of charge analyser for determining the state of charge of the at least one second thermal energy storage device, and a controller configured to control the at least one heat pump, the at least one first thermal energy storage device, the at least one second thermal energy storage device, and the at least one renewable energy generation device. The controller is configured to control, in dependence on at least the state of charge of the at least one first thermal energy storage device and/or the state of charge of the at least one second thermal energy storage device, whether one of and which of the at least one first thermal energy storage device and the at least one second thermal energy storage device is charged with energy provided by (a heat pump operation of) the at least one heat pump and/or energy provided by the at least one renewable energy generation device. Furthermore, the present invention relates to a method of using the energy management system.

The present disclosure is directed to a multi-utility. The multi-utility apparatus includes a water distiller configured to receive and distill saltwater. The multi-utility apparatus further includes a water heater configured to receive distilled water from the water distiller and heat the distilled water. The multi-utility apparatus further includes one or more utility devices fluidly connectable to the water heater. The one or more utility devices is configured to be operable under thermosyphon effect with the water heater. The multi-utility apparatus further includes a thermoelectric generator disposed on the water distiller and the water heater. The thermoelectric generator is configured to generate electricity based on temperature difference between the water distiller or the water heater and its surroundings.