National Grid had 3 ‘near-misses’ before blackout hit Britain

BRITAIN had three blackout ‘near-misses’ in the three months before last Friday’s power cut that caused chaos during rush hour.

National Grid is being investigated by the energy watchdog but the power system operator has faced criticism from the industry for failing to do enough to prevent blackouts.

The operator blamed last week’s ‘incredibly rare’ outage, which left a million homes without electricity, on an issue with the grid’s frequency following two generators going offline unexpectedly at about 5pm on Friday.

Ofgem will look at the National Grid’s handling of the energy system in the aftermath of the major blackout. The first in a decade, it followed Hornsea wind farm in the North Sea and a gas power plant in Bedfordshire shutting down. National Grid said it would co-operate with Ofgem and energy firms to ‘ understand the lessons learned’ after the shutdown caused rush-hour chaos.

Industry figures claim that National Grid has known of the increasing risk of a major outage ‘for years’ and has had a string of near misses over the past few months, reported The Guardian.

Every month since May has seen a major drop in the grid’s frequency, which usually operates at 50Hz. On three occasions, the frequency has fallen below 49.6Hz – the most severe drop since 2015 – with the legal limit being 49.5Hz.

Friday’s blackout saw it drop as far as 48.8Hz.

One near-miss in May followed three units at an EDFrun gas plant in Nottinghamshire going down without warning, with a blackout only avoided through the use of back-up electricity supplies.

A second incident in May and another in July saw the frequency almost dipping below the legal minimum.

Ofgem has demanded a report on the blackout by the end of the week and a full technical report by early September as concern over the National Grid’s handling of the system has grown.

Steve Shine, who heads battery company Anesco, said: ‘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.’

Duncan Burt, director of operations at the National Grid Electricity System Operand ator, said: ‘ There were no near-misses nor early warning signs. Rather this is a highly unusual event, without precedent in the past ten years.

‘We work with Ofgem to set the agreed limits of frequency of electricity output to keep the whole system safe and the lights on. All the time until Friday’s events, the system has remained within safe limits. We are conducting a thorough internal investigation will report our interim findings in detail to Ofgem by the end of this week. We can and must learn lessons from Friday’s events – however rare their occurrence – as National Grid and as an energy industry.’

The National Grid has a number of back-up energy contracts to allow it to stabilise the grid and remain above the 49.5Hz limit. It has deals with power plants and energy firms to increase electricity output to cover any shortfall in the event of an outage.

There are even some agreements with businesses, including factories and supermarkets, who can temporarily reduce their energy demand to stabilise the energy grid.

But some of the firms who supply back-up services, such as battery and diesel farms, have warned not enough is being done to protect against future outages.

Mr Shine called for a greater volume of back-up supplies ‘which can be called into action when the frequency drops. This would have prevented the need to turn the power off’.

‘Aware of this potential issue’