Consumers take a reliable and safe supply of electricity for granted. One thing that often escapes their attention is that operating a reliable grid requires constant corrections. The corrective measures taken by the grid operators are referred to as «ancillary services».
Ancillary services maintain the frequency and the voltage within a secure, stable range and compensate for the difference between electricity production and consumption. Ancillary services include schedule and congestion management as well as the provision of control energy.
As part of schedule management, Swissgrid works together with other operators to calculate the current capacity of the transmission grids and passes this capacity on to the market players.
Congestion management prevents congestion, which occurs if more electricity is traded than the grid can cope with.
The control energy ensures grid stability and balances out the Swiss transmission grid within seconds. It thus prevents the risk of grid fluctuations – for example, during a a power plant failure.
A stable grid requires the constant balancing of electricity generation and electricity consumption. Control energy is needed to achieve this. If this balance is not achieved, the worst-case scenario is a power system failure.
