The feed-in tariff is a government-regulated financial compensation for operators of photovoltaic systems who feed surplus solar power into the public grid. In short, it refers to the fixed amount of money per kilowatt-hour (kWh) paid by the local grid operator for the electricity supplied to the grid over a legally guaranteed period.
In a nutshell: When a solar system generates more electricity than can be directly consumed or stored at that exact moment, this energy is not lost. It automatically flows into the power grid, and a specified tariff is paid for it. This provides a reliable financial baseline component for system calculations.
How is the feed-in tariff regulated by law?
In Germany, the feed-in tariff is based on the Renewable Energy Sources Act (EEG). The tariff rate is locked in at the time the PV system is officially commissioned and remains unchanged for the current calendar year plus an additional 20 years. This provides system operators with long-term planning security.
The exact tariff amount depends on various factors – primarily the total installed capacity of the system (measured in kWp) and the chosen allocation model. A fundamental distinction is made between "self-consumption" (surplus feed-in) and "full feed-in". The latter option receives a higher tariff rate since no electricity is retained for personal use.
The role in modern system operation
While the feed-in tariff was extremely high in the early years of photovoltaics and served as the main driver of profitability, the dynamics in today's market environment have shifted significantly:
- Focus on self-consumption: Since the purchase price for grid electricity is significantly above the current feed-in tariff rate, direct consumption or storing energy locally is economically much more attractive. Today, the feed-in tariff functions primarily as a solid safety net for unused surpluses.
- Degression: The tariff rates for newly installed systems decrease slightly at regular intervals (so-called degression). Therefore, implementing PV projects promptly allows securing the respective current, higher subsidy rate for two decades.
- Direct marketing as an alternative: Above a certain system size (in the commercial sector), the classic feed-in tariff is often no longer mandatory or available. In these cases, it is replaced by direct marketing, where the electricity is traded on the power exchange at current market prices.
Significance for B2B project planning
For solar installers, planners, and specialist partners in the B2B sector, precise knowledge of the current EEG guidelines forms the foundation of every economic viability calculation. A combination of maximum self-consumption optimization (via storage systems) and the calculated residual feed-in tariff ensures the shortest payback period and maximum return on investment for the overall system. High-quality components secure stable and reliable yields over the entire 20-year tariff period.