This primarily depends on solar radiation but also on the heat withdrawn from the storage during heating through hot water usage or by the heating system. Nevertheless, a theoretical consideration can be made assuming constant conditions. To heat 1 liter of water by 1 degree, an energy amount of 1.16 Wh is required. For instance, a storage tank with a capacity of 300 liters, heated from 10 °C to 60 °C, could store 17.4 kWh of energy. To accommodate this energy in the storage with a constant 2 kW heating power would take approximately 8.5 hours. For a more practical, year-round assessment of the system, it is recommended to check with the my-PV Power-Coach.