UK power cut: The National Grid reportedly suffered three almost blackouts in recent months
The massive power cut last weekend affected trains, airports, hospitals and traffic lights. Blackouts were reported across the South East, Midlands, South West, North East and Wales. National Grid said it was caused by issues with two power generators but the problem has since been resolved.
However, industry sources told The Guardian the National Grid was aware of potential blackout “for years”.
Steve Shine, chairman of Anesco, a battery company, added: “It would be easy for National Grid to write this incident off as a fluke event, but they have actually been aware of this potential issue for many years.”
According to the paper, the system operator has suffered a severe dip in the grid’s frequency every month since May.
The normal range is around 50Hz but sources claimed this fell below 49.6Hz on three different occasions.
The figures come as Friday’s blackout was triggered by a 48.88Hz slump.
A spokesman for National Grid told The Guardian that these events were “independent”.
He said: “There was no trend or prediction of more frequency excursions.
“Over the past four years frequency has regularly fluctuated between the agreed limits, as part of the normal day-to-day operation of the electricity system.”
A Government investigation has since been launched into the power cut which affected millions.
Andrea Leadsom, Secretary of State for Business, Energy and Industrial Strategy, said Friday's power outage had caused "enormous disruption".
She added: "National Grid must urgently review and report to Ofgem.
"I will also be commissioning the Government's Energy Emergencies Executive Committee to consider the incident."