A Notification of Inadequate System Margin (NISM) was issued for 16:30 to 18:30 as a number of faults at Rugeley, Fiddlers Ferry, Didcott & Eggborough powerstations added up to tighten margins. At the same time a total lack of wind generation, put National Grid into a spin.
Some articles on this event describe a NISM as a “last resort” measure, as this is taken from National Grid’s own publications. However there are further steps before blackouts.
HRDR – High Risk of Demand Reduction
DCI – Demand Control Iminent
Following a NISM, existing power suppliers get very rich, very quickly. An offer of £2,500/ Megawatt hour 40x average price from Severn Power was accepted.
All this on a warm November afternoon.
See how the Telegraph has covered the incident.