The self-consumption rate, also called self-consumption share or simply self-consumption, indicates what percentage of the solar power generated is consumed by the user themselves. This percentage varies depending on consumption, the peak output of the photovoltaic system (kWp), and whether or not a battery storage system is installed.
The self-consumption rate is expressed as a percentage and is calculated as follows:
Self-consumption rate (%) = ( Σᵢ₌₁¹² ( Self-consumptionᵢ / Generationᵢ × 100 ) ) / 12
This means: The average of the monthly self-consumption percentages over 12 months.
Self-consumption (PV electricity) = Generation − Feed-in
In contrast, the degree of self-sufficiency describes the percentage of electricity demand that still needs to be purchased from the grid in order to cover total electricity consumption.