This is a first step in the resolution of the issue. The second step is now to develop a plan for returning the missing energy to the system and putting the situation back to normal.
ENTSO-E, in close interaction with the European Commission, is trying to identify a sustainable long term solution that will avoid that this happens again.
Frequency deviation in continental European grid leads to grid time deviations06.03.2018
The deviations originate in the control zone of Serbia, Macedonia, Montenegro (a.k.a. the SMM control block), especially in Kosovo and Serbia. Too little energy is being fed into the grid in this block.
These slight frequency deviations have no significant effect on the security of supply. Nonetheless, the frequency deviation must be corrected as quickly as possible.
Up to the beginning of March, the continuous frequency deviation in the European grid resulted in a grid time deviation of about six minutes. This deviation (frequency reduction below 50 Hz) has an effect on all electronically controlled clocks (e.g. radio alarm clocks and oven timers), which, in contrast to quartz clocks, use the frequency in the electricity grid as a clock generator.
The operators of the continental European grid will continue to monitor this deviation and Swissgrid will document it regularly.
The European Network of Transmission System Operators for Electricity (ENTSO-E) is now working with the affected grid operators to develop solutions. To compensate for the grid time, it will be necessary to feed additional energy into the grid over the course of several weeks once an agreed solution is implemented. The current status of the deviation can be viewed on the Swissgrid website.