
Energy watchdog Ofgem has demanded an urgent report from National Grid after a major power cut yesterday caused travel chaos and cut electricity for almost one million people in England and Wales.

Huge swathes of the country were left without power after two major generators failed yesterday afternoon within minutes of each other.

The crisis began when a gas fired power station at Little Barford, Bedfordshire failed at 4.58pm, followed two minutes later by the Hornsea Offshore wind farm in the North Sea.

A major review has been launched into the blackout but the National Grid is 'confident' that there was no 'cyber attack' on the system.

Large swathes of the country were affected by power cuts yesterday including Bristol, Exeter and Newport. The capital was particularly badly affected, with the Victoria Line closed and King's Cross evacuated

Commuters were left in darkness as they were evacuated from train stations, such as Clapham Junction in London which had lost power during the middle of the rush hour

Both plants were back running within 15 minutes, but the impact of the lack of supply lasted several hours, leaving many commuters stranded or facing long delays.

Julian Leslie, Head of National Control at the National Grid Electricity System Operator said: 'We had an unplanned near simultaneous event on our network. This event was the loss of two generators which connect to the national grid network in order to export their power.

'As a result of this, this rare event, the system needs to protect itself. What was happening was as the frequency was falling, the system could see this and unfortunately the way the system protects itself is to lose some demand. You would have seen this in a temporary and short power cut.'

Mr Leslie confirmed the system was working a short time later.

The power cut stopped traffic lights from working, plunged Newcastle Airport into darkness, affected Ipswich Hospital and caused huge disruption on the railways during the busy Friday night commute.

Tube passengers have been thrown into darkness on the Victoria Line, after a power cut hit large parts of the UK yesterday

Customers were forced to finish their shopping in darkness as a Sainsbury's store in Sydenham, south London was hit by the widespread power cut

A chef in Cornwall stands in the dark as machines and lights were switched off during the mass outage yesterday. It has impacted the Fistral Beach Boardmasters surf competition

At 5pm the Hornsea Offshore wind farm in the North Sea, pictured, was knocked offline. The national Grid tried to increase power to the network from other generators but were forced to suspend supplies to protect the network. Despite the power loss only lasting 15 minutes, the impact of the blackout is still impacting travel arrangements this morning

Commuters had to use the torches on their phones as they walked in complete darkness at Clapham Junction during a power cut

A National Grid Electricity System Operator spokesperson said: 'We appreciate the disruption caused by yesterday's power outage and investigations have continued overnight to better understand the situation. As the Electricity System Operator we do not generate power directly, but use the power made available by the industry to manage the system and balance supply and demand.

'The root cause of yesterday's issue was not with our system but was a rare and unusual event, the almost simultaneous loss of two large generators, one gas and one offshore wind, at 16.54pm. We are still working with the generators to understand what caused the generation to be lost.

'Following the event, the other generators on the network responded to the loss by increasing their output as expected. However due to the scale of the generation losses this was not sufficient, and to protect the network and ensure restoration to normal operation could be completed as quickly as possible, a backup protection system was triggered which disconnects selected demand across GB.

'Following the incident, the system was secured, and the Electricity System Operator gave the all clear to the Distribution Network Operators (NDOs), power companies who are responsible for supply at a local level, within 15mins, so that they could start to restore demand.

'All demand was reconnected by the DNOS by 17.40pm. We appreciate the disruption cause and will continue to investigate, with the generators involved and wider stakeholders, to understand the lessons learned.'

Ofgem said on Friday night: 'In any incident the priority is to get power restored to customers as quickly as possible. National Grid has now informed Ofgem that the system has been restored.

'However, Ofgem understands the frustration this power cut has caused consumers. Ofgem has asked for an urgent detailed report from National Grid so we can understand what went wrong and decide what further steps need to be taken. This could include enforcement action.'

A back-up generator failed at Ipswich Hospital after the power cut, a hospital spokeswoman said.

The generator which was supposed to supply power to outpatient areas of the hospital did not work as expected.

'There were some issues with regard to our outpatient areas and the generator that provides cover (to them),' said a spokeswoman for East Suffolk and North Essex NHS Foundation Trust.

She said other generators 'kicked in as was required' and 'patients were kept safe and cared for throughout'.

Traffic lights went dark at a busy junction on Northcote Road near Clapham Junction, south west London (pictured)

People walking in complete darkness at Clapham Junction station in London during a power cut

Commuters abandoned a train from Highbury and Islington, after a power outage caused it to stop on the tracks

Commuters are taken off a Thameslink train yesterday following the power outage, which caused major disruption across the country

Manuel Cortes, general secretary of the Transport Salaried Staffs Association slammed the government's handling of the crisis.

He said: 'We urgently need answers from the Government over this fiasco. Having our rail network brought to a standstill in this way is totally unacceptable.

'We've seen thousands of passengers stranded, unable to board trains and a number of cancellations; others have been taken off trains and onto the tracks. We need to know why this occurred and the lessons to be learned.

'As we face the growing prospect of a No Deal Brexit it's reasonable to wonder if this is a foretaste of things to come. Along with an economy sliding towards recession and expected food shortages we now seem to be a country where blackouts happen without warning, travel grinds to a halt, traffic lights stop working and - terrifyingly - hospitals are left without power.

'Boris Johnson can't remain silent over this - he must quickly provide answers and illumination.'

An office block in Newcastle was left in the dark as its electricity cut out during the power outage

The National Grid has described the loss of power across the country on Friday as an 'incredibly rare event'.

Spokesman Duncan Burt told the BBC Radio 4 Today programme that two power stations had disconnected 'almost simultaneously'.

He added: 'What happened then is our normal automatic response mechanisms came in to help manage the event, but the loss of power was so significant that it fell back to a set of secondary back-up systems which resulted in a proportion of electrical demand across the country being disconnected for a short period to help keep the rest of the system safe.'

Mr Burt said the power loss events happened 'very, very quickly' but the safety protection systems 'worked well'.

He explained that National Grid will be looking at its readings to ensure the protection systems are set up correctly.

'We really appreciated the very large scale of disruption caused to travellers in and out of London in particular, but across the country,' he said.

Mr Burt added: 'That's something we want to look at as an industry to make sure that when those automatic protection systems fire that they are doing it in the right way and that we're having the minimal impact that we can on everyone's daily lives.'

Mr Burt said National Grid would provide 'a detailed technical report' to Ofgem.

He added: 'This will require careful study to make sure that we do learn any lessons that come out of it and that the next time this happens disruption is minimised and hopefully a lot less than it was last night.'

Asked if National Grid would investigate the possibility of the power cut being triggered by a cyber attack, Mr Burt said: 'We are already very confident that there was no malicious intent or cyber attack involved.'

There was darkness at a Debenhams in Cheshire following the power cut on Friday afternoon. The power was off across the entire Cheshire Oaks Designer Outlet

King's Cross Station in London was evacuated following the power cut and commuters were forbidden from passing through the ticket gates

The problems lasted about 15 minutes before power was fully restored, she added.

Professor Tim Green, co-director of the Energy Futures Laboratory, Imperial College London, believes the two generators disconnected were at Little Barford and Hornsea.

He said: 'The first generator to disconnect was a gas fired plant at Little Barford at 16:58. Two minutes later Hornsea Offshore wind farm seems to have disconnected.

'This might be linked to disturbance caused by first generator failing; might not.

'We will need to wait for National Grid's full technical investigation to get to bottom of that.'

Around 300,000 UK Power Networks customers were affected in London and the South East, a spokeswoman said, and Western Power Distribution said around 500,000 people were affected in the Midlands, South West and Wales, with power restored to them all shortly after 6pm.

A spokeswoman for Northern Powergrid, which serves Yorkshire and the North East, said 110,000 of its customers lost power, while at least 26,000 people were without power in the North West of England, Electricity North West said.

The escalators at King's Cross station stopped working following the power cut and commuters were prevented from entering the station

Embarrassingly, Chancellor Sajid Javid visited National Grid bosses and trainees at its Eakring Training Centre, just hours before the power cut

Shadow Business and Energy Secretary Rebecca Long Bailey said "Disruption on this scale is unacceptable.

'National Grid - which in May posted £1.8 billion in profits and increased dividend payouts to shareholders - must urgently provide a full account of what went wrong, and why.

'Integrating large amounts of renewable energy will require planned and coordinated investments in our networks, which is why Labour has committed to taking the grid back into public hands.'

Ticket barriers stopped working after a major power cut caused a loss of electricity across vast swathes of the country (pictured, at Clapham Junction in London)

Trains began to run out of King's Cross late on Friday night after the station was shut down amid 'apocalyptic' rush-hour scenes across England.

The first train bound for Peterborough left the central London station at around 9.30pm after all services were halted for several hours.

Passengers were filmed forcing their ways through the barriers in an attempt to get themselves on to the first northbound service.

London North Eastern Railway tweeted on Friday evening: 'Services heading towards London are now able to depart however due to congestion across the network it will take some time to clear the backlog.'

Thameslink said their services will not be running north out of London for the rest of the day.

Harriet Jackson described an 'apocalyptic' scene when she witnessed the power outage causing traffic lights to cut out on Northcote Road in Battersea, south London, after leaving Clapham Junction train station at around 5pm.

'(I) realised that nothing was open and there was hardly any phone signal,' the 26-year-old told PA.

'All the traffic lights were down, but there were no police present, which meant it was dangerous to cross - cars weren't stopping either.

'It was like witnessing something out of an apocalyptic film.

'No one knew what was going on and, given it's a Friday afternoon, it's the last thing you want to encounter.'

Newcastle Airport was also plunged into darkness during the major power cut.

On Friday afternoon, a Network Rail spokeswoman said: 'There was a power surge on the national grid this evening which means we lost power to all our signalling over a wide area, including the Newport, Gloucester, Ashford, Bristol, Eastbourne, Hastings, Three Bridges and Exeter areas.

'All trains were stopped while our back-up signalling system started up.'

The Department for Transport confirmed they were working with Network Rail to reduce disruption.

Problems with power were first detected late on Friday afternoon when UK Power Networks, which controls power lines for London and the South East, and Western Power Distribution in the Midlands, the South West and Wales both confirmed widespread outages.

People have been taking to Twitter to complain about the power outages (above and below), which caused delays of up to two hours for some commuters

People walking through Clapham Junction station in London during a power cut. Many appeared to emerge from darkness, following the loss of power at the station

The outage, which not only affected power at Clapham Junction (pictured), also caused traffic lights to go down and trains to come to a standstill

An empty shop in darkness at Clapham Junction station in London during a power cut, which has caused 'apocalyptic' rush-hour scenes across England and Wales

In Cheshire, a major power outage left people unable to purchase fuel at Tesco. And it even appeared as if the store was giving it away for free

A notice board at Clapham Junction in London ceased to function following the power cut, with passengers left waiting on the platform

Passengers at London's King Cross were prevented from entering the station following a major power cut which affected large swathes of the country

A motorist gets out of his vehicle to direct traffic after a power cut in the area leads to traffic lights failing in Gateshead

UK Power Networks, who control power lines for London and the South East, and Western Power Distribution in Midlands, the South West and Wales both confirmed widespread outages (pictured, a motorist directing traffic in Gateshead, near Newcastle last night)

There were delays and cancellations across the rail network yesterday following the power outage, which affected large swathes of the country

Eric Anchorage is stuck on a plane at Luton Airport with his family following the power outage

Large swathes of the country were left affected by the outage, which included London and the south-east of England. Also affected was the Midlands and parts of south-west England

Social media is flooded with hilarious memes as the lights go out across the country One million people have been affected by major blackouts after power cuts hit homes, airports, traffic lights and trains due to a 'failure of the National Grid'. Amid the chaos which plunged large swathes of the UK into darkness on Friday, people have been making light of what has otherwise been a frustrating experience for many. Twitter users have flooded the internet with hilarious memes following the power outage. In one side-splitting meme, a man called Brian Yim Lim said: 'The UK is so broken that we've resorted to turning it off and on again. #powercut'. There was no shortage of Lord of The Rings memes either, with one person sharing a picture of King Theoden uttering the words 'You have no power here!' from the 2002 film The hilarious tweet has since gone viral, receiving 740 retweets and 2,200 likes. Others took to sharing Simpson memes to convey the confusion and panic in the aftermath of the power outage. One person shared a picture of Homer Simpson carrying a sign reading 'The End is Near' with the caption: 'When the #PowerTrip hits the UK for 20 minutes or so... #powercut'. A man called Daniel Smith shared a picture of Homer Simpson looking panicked while at work at his power plant station, with the caption: 'Currently at the National grid #powercut'. There was no shortage of Lord of The Rings memes either, with one person sharing a picture of King Theoden uttering the words 'You have no power here!' from the 2002 film. One man drew attention to the food in his freezer, implying the power cut gave him a good excuse to eat all his ice lollies before they melted. 'Got a power cut and all the neighbours are out buzzing about it .. like it amazing *winking face emoji* What about my fab ice lollies ? I believe I better start eating them.' Amid the chaos which plunged large swathes of the UK into darkness on Friday, people have tried to make light of what has been a frustrating experience for many Another person simply tweeted a picture of several cartoon pairs of eyes peering out from darkness. One Twitter account shared a GIF of Hot Fuzz actor Simon Pegg clutching a pint, with the caption: 'This #powercut appears to be hitting places across the UK. Time to head to the Winchester.' Liam Kerridge from Newcastle Upon Tyne posted a hilarious meme of Phoebe from friends running around in a panic with the words 'What do I do?'. 'When the TV went off and I'm on 10% battery,' he wrote. While some worried about how they would charge their phones, one person had something else entirely on their mind. '#powercut causing chaos here in London, how on earth do I set the clocks on the ovens? #poweroutage #1stworldproblems,' one man named Rikki tweeted. Paul was struggling with a similar problem, and wrote on Twitter: '#powercut and the worst thing is when it comes back on having to reset all the clocks again.' Advertisement

UK Power Networks tweeted on Friday evening: 'We're aware of a power cut affecting large parts of London and South East.

'We believe this is due to a failure on National Grid's network, which is affecting our customers.'

Western Power Distribution shared a similar message, and said they were in the process of restoring power to customers.

'What happened is a major offshore wind generation site and a gas turbine failed at the same time,' Devrim Celal, of Upside Energy in London, a contractor with National Grid, was reported saying. 'There was a significant shortage of generation, and that sudden drop created ripple effects across the country.'

Professor Tim Green, co-director of the Energy Futures Laboratory, Imperial College London, believes the two generators disconnected were at Little Barford in Bedfordshire and Hornsea in Yorkshire.

He said: 'The first generator to disconnect was a gas fired plant at Little Barford at 16:58. Two minutes later Hornsea Offshore wind farm seems to have disconnected. This might be linked to disturbance caused by first generator failing; might not. We will need to wait for National Grid's full technical investigation to get to bottom of that.'

Commuters described 'apocalyptic' scenes as they tried to make their way home during the evening rush-hour.

The events immediately sparked speculation over the cause. Last night, the National Cyber Security Centre said there was, as yet, no evidence of hackers assaulting the power network.

Embarrassingly, Chancellor Sajid Javid visited National Grid bosses and trainees at its Eakring Training Centre, just hours before the power cut. The mayhem last night was at its worst on the transport network. Commuters travelling on the London underground and at Clapham Junction were plunged into darkness.

King's Cross in London, one of Britain's busiest stations, had to be evacuated and thousands of commuters were trapped on trains which were left stranded. All services were cancelled between London and Bedford, Cambridge and Peterborough. At Newcastle airport, travellers looked on bemused as information screens went blank.

A train from Kentish Town to St Pancras in London stopped as a result of the power cut and commuters were told to leave the train and walk back to the station

Commuters on a train from Highbury and Islington in London were made to disembark their train and walk back to the station following a major power cut

People walking in complete darkness at Clapham Junction station in London during a power cut, which has caused 'apocalyptic' rush-hour scenes across England and Wales

People were prevented from entering King's Cross station following a major power cut in the capital today. Other areas of the country were also affected

People lie down on the floor as they faced cancellations and delays following one of the worst power cuts to hit the country in years

Train services in and out of London, including Thameslink (pictured, passengers at the station), Southern and Gatwick Express are facing delays and cancellations

British Transport Police officers are assisting at train stations after power cuts caused widespread disruption (pictured, commuters caught up in the power cut chaos on Thameslink)

Huge queues gathered at St Pancras station yesterday as information boards went blank

The Victoria Line has been closed following the power outage, with commuters pictured flooding out of the line

Passengers waiting for their trains were left staring at blank screens as the major power cut caused chaos across the country. British British Transport Police officers are assisting at stations

A Twitter user posted a darkened Clapham Junction railway station in south west London

Passengers wait for news at Peterborough station during travel disruption on the East Coast mainline, after a large power cut has caused 'apocalyptic' rush-hour scenes across England and Wale

Some have been making light of the power cut (above and below), which caused outages across the UK this afternoon