Surplus Feed-in
Operating model where solar electricity is primarily self-consumed and only the surplus is fed into the grid.
Also known as: Excess Feed-in, Surplus Feed-in Model
What Is Surplus Feed-in?
With surplus feed-in (also excess feed-in), the generated solar electricity is primarily consumed within the household. Only the surplus that is not immediately needed flows into the public grid and is remunerated.
How It Works
The inverter feeds solar electricity into the home grid. Active consumers (refrigerator, cooker, washing machine) are directly supplied. When generation exceeds consumption, the rest automatically flows into the grid. A bidirectional meter records both feed-in and grid purchase.
Economics
| Area | Value |
|---|---|
| Feed-in tariff (up to 10 kWp) | 8.1 ct/kWh |
| Avoided grid purchase | approx. 30—35 ct/kWh |
| Savings per self-consumed kWh | approx. 22—27 ct/kWh |
Every self-consumed kWh saves the difference between the electricity price and the feed-in tariff. Therefore, maximising self-consumption is economically sensible.
Optimising Self-Consumption
- Battery storage for evening and night-time use
- Consumption adjustment: Run energy-intensive appliances during the day
- Heat pump and EV as flexible consumers
Practical Tip
Surplus feed-in is the standard model for private rooftop systems. In combination with battery storage and smart load management, profitability can be further improved.
Related Terms
Full Feed-in
Operating model where all generated solar electricity is fed into the public grid -- with a higher tariff per kWh.
Self-Consumption
Share of self-generated solar electricity consumed directly in the household rather than fed into the grid.
Feed-in Tariff
Legally guaranteed remuneration for solar electricity fed into the public grid, governed by the EEG.
Battery Storage
Energy storage for PV systems that stores surplus solar electricity and releases it on demand.