UK Windfarm Failure Led to Power Cut: FT
It was a lightning strike on the UK grid near Cambridge, coinciding almost instantaneously with the loss of supply from the Hornsea wind-farm, that triggered the power cut August 9, according to sources investigating the cause of the problem and cited by the Financial Times August 19. Hornsea output went from 800 MW to zero in less than a second, not the previously thought minute, which suggests that the safety systems might have accidentally caused the shutdown.
Operator Orsted, the Danish utility, acknowledged that a technical fault had meant the rapid closure but did not tell the FT whether it, or the gas-fired Little Barford plant had gone off line first. But the report is expected to say that the frequency of the grid did not drop below 48.5 hertz until Little Barford went offline. Reaching that frequency in turn led to National Grid shedding demand.
The investigator's initial theory was that Little Barford, also in Cambridgeshire, went offline first. National Grid had to submit an interim report to the regulator Ofgem August 16, and also has to explain itself to the government.
Analysts have said that it might be time to revisit the sharing of liabilities beween National Grid and the local network operators, particularly as more decentralised power comes online.
National Grid declined to comment on the FT article, telling NGW it was waiting comments from Ofgem on its own report.