An existing air heat pump will be used and the system will be supplemented by a stratified tank with a volume of 3,000 l. The system will be equipped with a new heat pump. The existing photovoltaic system was expanded by the 15 kW Smart Energy (PV) system in order to be able to use solar power directly for hot water generation. Smart Energy (PV) only uses the quantities of PV electricity that cannot be consumed on the campsite - this is made possible by the use of the grid sensor, which records the quantities of overcurrent and thus regulates the output of Smart Energy. A two-stage cascade heating system with an output of 200 kW was used to efficiently generate the high volumes of fresh water. The superordinate ratiotherm central controller monitors and controls all consumers and producers optimally.