Power up: Grid may need upgrade to avoid more blackouts
Experts have questioned if National Grid’s processes and backup systems are up to scratch after the worst power cut in a decade ground trains to a halt.
A report, released today by National Grid, showed the system followed correct procedure when lightning struck on 9 August.
However it was not enough as lights went off in 1.1m homes and trains stopped in their tracks. Newcastle Airport and Ipswich hospital were also left without power.
The strike hit at 4.52pm on Friday 9 August, but protection systems soon got it back running, National Grid said.
However less than half a second later the strike had knocked out most of the Hornsea offshore wind farm. A second later Little Barford gas power station reduced the power it was supplying to the grid.
Taken together this became too much for the grid to cope with and it activated emergency protocols to cut supply to over a million households. It is still unclear what caused the plants to fail.
“It seems like the system responded as designed. So the question will be were the design and the plan correct and what can we do to improve it?” said Thomas Edwards at Cornwall Insight, a consultancy.
Other experts said that Britain might need to invest in more backup power as increasing reliance on electricity means power cuts become more and more disruptive.
National Grid is required to have enough spare capacity to offset the loss of the largest generator on the system.
However at around 1 gigawatt (GW) this was not enough during the 9 August power outage. At its highest the outages triggered a loss of nearly 1.9 GW generation.
“Given that we’re more and more on electrical power, should we be preparing for more unlikely events?” said Harry Sturgess at Aurora Energy, a consultancy.
National Grid’s current 1 GW adds around £2 a year to household bills, Sturgess said.
The report showed that outages on the railways were not the fault of local distributors. Power was maintained to the tracks, but one class of train shut itself down as it sensed problems in the network.
Around half of drivers were later unable to restart their trains, and delays piled up as engineers were dispatched.
Read more: Government sets out scope for probe into National Grid outage
Commuters who were hit by the outage will now be waiting for reports from Ofgem and the Department for Business, Energy and Industrial Strategy (Beis).
Questions remain over how a routine event like a lightning strike hitting the grid could cause such major outages.