Self-Sufficiency Rate
Share of electricity consumption covered by the own PV system -- indicates independence from the electricity grid.
Also known as: Self-Sufficiency, Energy Autarky, Autarky Rate
What Is the Self-Sufficiency Rate?
The self-sufficiency rate indicates what percentage of total electricity consumption is covered by the own photovoltaic system. It describes the independence from the public electricity grid.
Calculation
Self-sufficiency rate = Self-consumed solar electricity / Total electricity consumption x 100%
Difference from Self-Consumption
| Metric | Reference | Statement |
|---|---|---|
| Self-consumption rate | Generation | How much solar electricity is used on-site? |
| Self-sufficiency rate | Consumption | How independent am I from the grid? |
Example: A system generates 10,000 kWh, the household consumes 5,000 kWh, of which 2,500 kWh from the PV system:
- Self-consumption rate: 2,500 / 10,000 = 25%
- Self-sufficiency rate: 2,500 / 5,000 = 50%
Typical Self-Sufficiency Rates
| Configuration | Self-Sufficiency Rate |
|---|---|
| PV without storage | 25—40% |
| PV with storage | 50—75% |
| PV + storage + heat pump | 40—60% |
| 100% self-sufficiency | Economically impractical |
Practical Tip
100% self-sufficiency is technically possible but uneconomical, as the storage for the winter months would need to be extremely large. A self-sufficiency rate of 60—70% offers the best balance between independence and cost-effectiveness.
Related Terms
Self-Consumption
Share of self-generated solar electricity consumed directly in the household rather than fed into the grid.
Battery Storage
Energy storage for PV systems that stores surplus solar electricity and releases it on demand.
Surplus Feed-in
Operating model where solar electricity is primarily self-consumed and only the surplus is fed into the grid.