The primary control power must be available within 30 seconds. It is used to compensate for grid instabilities at short notice. Around 780 MW is required for this in Germany. The providers receive a performance price for the mere provision of power reserves. In the event of a demand for primary control power, the provider ramps the system up or down within 30 seconds and thus balances the electricity grid. The balancing works both in the event of electricity overproduction (negative balancing power) and electricity shortages (positive balancing power).