The government has launched an inquiry into the massive power cut that brought chaos to the road and rail networks last Friday.
Almost one million people were left without electricity, while the power supply to Newcastle airport and Ipswich hospital was also affected. Andrea Leadsom, energy secretary, said that the power cut had caused “enormous disruption” and ordered National Grid to “urgently” explain to Ofgem how it had been allowed to happen.
She said that she would also ask the energy emergencies executive committee to look into the incident and examine whether National Grid’s procedures are fit for purpose, as well as looking at potential technical performance issues. National Grid has said that the outage was prompted by the “rare and unusual” loss of two large generators in close succession.
A gas-fired power station in Bedfordshire failed shortly before 5pm. That was followed by the disconnection of an offshore wind farm two minutes later.
Duncan Burt, operations director at National Grid, said that the loss of two generators had triggered an automatic response that temporarily disconnected electrical demand to “help keep the rest of the system safe”.
The blackout led to traffic lights no longer working and brought chaos to the railway network, with some passengers stuck on trains for up to nine hours.
It left Ipswich hospital without power for 15 minutes after a back-up generator did not work as expected.