Cornwall Insight comments on National Grid ESO’s blackout investigation

This morning Ofgem published National Grid’s investigation into the blackouts that occurred on 9 August. The regulator was concerned enough to launch its own examination to see what “lessons can be drawn” to “further improve the resilience of Britain’s energy networks”. The regulator will try and establish whether any network companies and generators were in breach of their licences.

Commenting on the report Tom Edwards Senior Modeller at Cornwall Insight, said:

“This initial report highlights several reasons behind this rare event. The event itself was caused by settings and sensor issues in response to a lightning strike. Wind power was not directly responsible for the outage.

“National Grid was holding 1GW of response* to cover the immediate consequence of the largest in-feed loss of electricity at the time (the Interconnectors), but the overall loss of transmission connected generation was over 1.3GW. In addition, an estimated 500MW of generation capacity was lost on the distribution system at the same time as the lightning strike.

“This highlights how increasingly interdependent and interconnected our systems have become, and it is essential that the effects of embedded generation** on the whole system are considered as part of operational security planning.  

 “The investigations will need to evaluate the way the National Grid assesses response and reserve given the changing mix of generation on the system and how services are provided and contracted for, including the liabilities on providers unable to fulfil their obligations.

“There is a balance here between the likelihood and scale of potential distribution and the amount consumers might be prepared to pay to avoid this in our increased digitalised aged.”


Notes to Editors

*Response – is the electricity that can be flowed onto the transmission system at short notice in the immediate aftermath of a disturbance and before all reserve capacity has come online.

** Embedded generation is licence exemptible generation connected at the lower voltage distribution networks.