Saving energy with a solar water heater

On average, an individual solar water heater (CESI) can cover 60% of domestic hot water needs (see this ADEME article). This means that a proportion of the energy consumed for domestic hot water is avoided. This value is only used if the user⋅ice does not know exactly how much energy they consume, and for the energy sources used to heat domestic hot water, i.e. electricity, gas, fuel oil and the heating network.