Three energy firms to pay £10.5m for failings over August blackout

Three energy companies will pay £10.5m for their failures to prevent a power cut after a lightning strike last summer that left more than a million customers in the dark and prompted travel chaos across large parts of the UK.

The energy regulator Ofgem said Hornsea One Ltd, a windfarm company part-owned by Ørsted, and RWE, the owner of a gas power station, each agreed to pay £4.5m for not remaining connected after the lightning strike. UK Power Networks, which runs distribution networks, will pay £1.5m for not following correct procedures.

Large parts of England and Wales were affected by the power cuts on the evening of 9 August, which caused massive disruption during the rush hour as train stations and traffic lights turned off.

A lightning strike on the Friday evening caused the Hornsea offshore wind farm and RWE’s Little Barford gas power station to stop generating electricity because of “unforeseen technical issues”. The strike also put offline about 150MW of smaller generation, known as distributed generation. National Grid Electricity System Operator (ESO), which manages the distribution of power in the UK, activated backups, but there was not enough available, meaning local network operators were forced to cut off customers.

The Office of Road and Rail, a separate government regulator, found that train companies had also contributed to disruption, which saw major London stations Kings Cross and Euston closed. Software flaws on some flaws caused extended delays for many commuters.

Ofgem also said it will review the structure and governance of National Grid ESO, after raising concerns about its response.

Jonathan Brearley, Ofgem’s executive director, said: “Consumers and businesses rely on generators and network companies to provide a secure and stable power supply. 9 August showed how much disruption and distress is caused to consumers across the UK when this does not happen. That is why it is right that companies that were unable to keep generating have paid into our consumer redress fund.

“Our investigation has raised important questions about National Grid’s Electricity System Operator, which is why our review will look at the structure and governance of the company.”

Ofgem said the power cut was caused by the “combined loss of two large generators, as well as the smaller loss of generation at a local level”.