Each electricity meter is assigned a ‘block letter’ between A and U. The letters F, I and O are not used.
The blocks are pre-determined and are designed to represent approximately 5% of the NI Electricity System. The areas affected by each block will be spread geographically across NI and can be found on our Block Map.
The number of Blocks that need to be disconnected simultaneously will depend on the direction given by SONI as to the level of the generation shortfall.
The NIE Networks Control Engineers will disconnect the required blocks according to the rota order.
In the event of a planned emergency power cut, different block letters are timetabled to be without power for typically around three hours once a day. However, depending on the severity of the scenario, power may be interrupted multiple times over the period of the event.
