Article 109 Reactive power ancillary services
United Kingdom
For each operational planning time-frame, each TSO shall assess, against their forecasts, whether its available reactive power ancillary services are sufficient to maintain the operational security of the transmission system.
In order to increase the efficiency of operation of its transmission system elements, each TSO shall monitor:
the available reactive power capacities of power generating facilities;
the available reactive power capacities of transmission-connected demand facilities;
the available reactive power capacities of DSOs;
the available transmission-connected equipment dedicated to providing reactive power; and
the ratios of active power and reactive power at the interface between the transmission system and transmission-connected distribution systems.
Where the level of reactive power ancillary services is not sufficient for maintaining operational security, each TSO shall:
inform neighbouring TSOs; and
prepare and activate remedial actions pursuant to Article 23.