Abstract: In a public electric grid (30) of an energy provider, the feed-in power of photovoltaic systems (10) are controlled depending on feed-in requirements, the feed-in power of the photovoltaic systems (10) being reduced to a non-zero fraction factor (B) of the maximum possible feed-in power. The photovoltaic systems (10) each comprise a photovoltaic inverter (20) and a feed-in electricity meter (50) on the AC side (20b) of the photovoltaic inverter (20), wherein the AC side feed-in electricity meter (50) continuously measures the power actually fed into the public electric grid (30) and transmits the respective measured power data. Then, the maximum possible feed-in power of the photovoltaic systems (10) is calculated based on the fraction factor (B) and the continuously measured power data time-correlated therewith, and the feed-in remuneration for the respective photovoltaic system (10) is determined based on the thus calculated maximum possible feed-in power.