A photovoltaic system has a plurality of subsystems, each with a photovoltaic generator and an associated inverter. The inverter has a control element for setting the maximum power point of its subsystem. A battery is connectible in parallel with the photovoltaic generator. The inverters are connectible to a power grid, which is operated by a utility operator. When a control device receives an emergency signal from the utility operator indicating impending instability of the grid, the following is initiated: If the battery voltage is above the current voltage as set by the MPP control element, the battery is immediately connected to the input of the inverter while the generator remains connected to the inverter. If the battery voltage is below the current voltage the battery connection is delayed until the MPP control element has adjusted the voltage. Then the voltage is further lowered to generate a discharge current from the battery.

A photovoltaic system has a plurality of subsystems, each with a photovoltaic generator and an associated inverter. The inverter has a control element for setting the maximum power point of its subsystem. A battery is connectible in parallel with the photovoltaic generator. The inverters are connectible to a power grid, which is operated by a utility operator. When a control device receives an emergency signal from the utility operator indicating impending instability of the grid, the following is initiated: If the battery voltage is above the current voltage as set by the MPP control element, the battery is immediately connected to the input of the inverter while the generator remains connected to the inverter. If the battery voltage is below the current voltage the battery connection is delayed until the MPP control element has adjusted the voltage. Then the voltage is further lowered to generate a discharge current from the battery.