Control energy is used by transmission system operators to balance unplanned fluctuations between electricity generation and electricity consumption.
It is difficult to store large amounts of electrical energy. Consequently, the consumption of electrical energy should be equal to the production at any time. Imbalances between electricity feed-in and electricity offtake are first minimised by setting them off against each other (balancing) or controlling the deviations of several grid area (balancing groups). Residual deviations in system balance have to be compensated by using control energy.
A distinction is made here between control reserve (capacity provision) and balancing (use of control reserve). In order to have enough capacity available at all times, control energy is tendered via a procurement platform and provided by qualified suppliers (producers as well as traders). If necessary, the reserved control energy is activated.
On these pages you will find data on the control energy tendered and used by 50Hertz, older publications can be found in the archive, while further information on the procurement of control energy and on prequalification is available here. You can learn more about balancing group settlement here.