wherein the DC grid comprises a DC bus that has the DC voltage,

wherein an energy generating system and at least one load are connected to the DC bus,

wherein the DC bus is connected to a higher-order grid,

wherein an electrical grid power is exchanged between the DC bus and the higher-order grid, wherein the electrical grid power is varied in order to maintain the DC voltage in the DC bus at a nominal voltage,

wherein the energy generating system comprises a PV generator that is connected to the DC bus via a DC-to-DC converter and exchanges electrical generator power with the DC bus,

in a normal operating mode, setting the electrical generator power to a normal operating power by the DC-to-DC converter as a function of an MPP power of the PV generator, and setting the normal operating power variably in a predetermined relation to the MPP power of the PV generator or fixedly at a value below the MPP power of the PV generator,

monitoring the DC voltage in the DC bus using the energy generating system,

in a grid support mode, setting the electrical generator power as a function of the DC voltage in the DC bus to a grid support power in order to counteract a power imbalance between a total electrical power supplied to the DC bus and a total power withdrawn from the DC bus, and

setting the grid support power as a function of a deviation of the DC voltage from its nominal value and/or a rate of change of the DC voltage,

wherein the grid support power is less than the normal operating power by a PV control power, and wherein the grid support power has an inverted sign with respect to the normal operating power when the deviation of the DC voltage in the DC bus from the nominal voltage and/or the rate of change of the DC voltage in the DC bus requires the PV control power greater than the MPP power.