Spain acknowledges that solar energy may have caused countrywide power failures: Investigation into outage escalates with suspicion of sabotage being considered by top court

The grid operator of Spain has acknowledged today the potential role of solar power in the recent blackout mayhem on Monday. The cause of the significant power outage that occurred across the Iberian Peninsula remains uncertain.

During a news conference, Eduardo Prieto, the System Operations Chief of Red Eléctrica, disclosed that there was a substantial loss of power generation in southwestern Spain. This loss led to system instability, resulting in the disconnection of the Spanish grid from the French grid.

Prieto mentioned that it is conceivable that the generation predominantly affected was from solar sources; however, it is too early to confirm. He reassured that the system has since stabilized and is functioning normally.

The partly state-owned operator’s preliminary assessment ruled out cyberattack as the cause of the outage, he added – but Spain’s top criminal court said it was investigating the possibility of ‘an act of computer sabotage on critical infrastructure’.

Although the causes are unknown, ‘cyberterrorism is among’ the potential explanations, while the ‘critical situation’ generated for the population meant an investigation was necessary, the Audiencia Nacional said in a statement. 

Pressure has been mounting on the Spanish government to explain the blackouts, which saw planes grounded, trains stopped and traffic brought to a standstill in major cities. 

Swathes of the country remain in a state of emergency. Brits are still held up in airports awaiting travel information, supermarket shelves are empty after yesterday’s panic buying, and a premature baby was in critical condition after being delivered in the garden of a Costa del Sol hotel during the outages.

David Alandete, a correspondent for Spain’s Diario ABC, had criticised the government’s ‘lack of transparency’, lamenting how the government had pursued ‘the deployment of renewable energy…without addressing’ maintenance and interconnection issues.

Isabel Ayuso, regional president of Madrid, with the conservative Partido Popular, also took aim at Pedro Sanchez’s socialist government, sharing her ‘regret’ at ‘the damage this could cause to the economy and our image in the world’.

‘It’s incredible that a country like ours can be left in the dark, with no clue as to where it came from, its causes, or how it happened,’ she said.

Red Eléctrica (REE) reported that by 6am local time today more than 99 per cent of the country’s electricity supply had been restored.

Passengers held up at Sants train station in Barcelona, Spain, Tuesday, April 29 

An employee of Spanish state-owned rail company RENFE speaks into a megaphone as passengers wait before boarding their train at Sants railway station in Barcelona on April 29

Red Cross volunteers distribute food and water bottles to passengers waiting to board their train at Sants railway station in Barcelona on April 29

Still, confusion remains around the exact cause of the blackouts. After the grid operator said its preliminary assessment had all but ruled out a cyberattack, the country’s High Court said it would open an investigation into the possibility.

In that were the case, Judge Jorge Calama would investigate it as a crime of terrorism, a court document showed.

REN, Portugal’s grid operator, said initially that they believed a ‘rare atmospheric phenomenon’ was behind the outages. 

Power supply was gradually restored in both Spain and Portugal from late Monday afternoon, though some operations were still unable to resume on Tuesday morning.

France was briefly affected, but recovered on Monday afternoon. 

The Madrid underground metro network said it had resumed operating at 8am local time with 80 per cent of trains circulating, but railway infrastructure operator Adif said most trains nationwide were not operating.

Renfe told commuters in Galicia that all train services were suspended until further notice.

Paul Collins, a teacher and marketing professional based in Madrid, told MailOnline today that hotel occupation reached 95 per cent last night as people sought last minute places to stay, unable to travel or get home.

The former news agency reporter said it would ‘probably take a day or two for supplies in stores to be stocked again’ after people panic bought, stocking up on essentials amid uncertainty over how long the outages would last.

‘Essentials like bread and milk were sold out,’ he said. ‘Shops are open again today and payment systems working.’

‘There will also likely be long queues at petrol stations because no-one could fill up yesterday.’

The outages have caused huge disruption across Spain and Portugal (Sants pictured today)

People wait at Sants station for the resumption of the train services due to a disruption in the regional train schedule, in Barcelona, Spain, 29 April

Employees stand inside a supermarket without lights in Burgos on April 28, 2025

Companies have told employees to work from home today, resulting in ‘very light’ traffic into the capital today.

‘Schools are open too. The one I work at, a private school has classes scheduled as normal. Public schools are open but classes are suspended. Hospitals, doctors all operating as usual.’

The outages brought chaos to major cities across Spain and Portugal as traffic lights stopped working, businesses were forced to close early and residents panic bought in shops, uncertain how long the blackouts would last.

A British expat working in Barcelona told MailOnline yesterday evening: ‘It’s absolute chaos. I would say 30 per cent of the lights are working. Most of them are not.

‘Traffic is crazy. The mopeds and motorbikes are heading down the cycle lanes. There are massive queues to catch the bus because without the metro there’s no way that anybody can get home from work.

‘There is power in some downstairs premises, so it’s not a total blackout. But internet up here doesn’t work at all. There’s also an eerie silence, apart from the cars. But everything is quiet.’

The English teacher, who wished to remain anonymous, added: ‘Nobody knows what is going on. I came up to do classes today and I’ve had to tell every single parent what’s going on because they have literally no idea.

‘Only the very few people who have access to internet, either because of their service or where they are, have been able to find out what’s going on. But so many people’s phones have no connection.’

A person walks down a downtown street during a power outage in Malaga, on Tuesday

People wait outside the Atocha train station in Madrid after its closure as a massive power outage hits Spain on April 28

Several people get money out of several ATMs at the access of a subway station during a blackout hit Spain and Portugal in Madrid

With locals in the dark on the causes of the blackouts, speculation grew as to the possible causes.

Local media soon began pointing to historic reports warning that the rapid integration of renewable energy sources could cause fluctuations in power levels, potentially leading to widespread blackouts.

Spain has one of the highest proportions of renewable energy – 56 per cent on average – in Europe.

And just days ago on April 16, Spain’s power grid ran entirely on renewable energy, including wind, solar and hydro power for the first time.

While sources of energy like wind and solar power are often fairly cheap and ‘secure’, reducing reliance on imports from abroad, their variability and storage issues pose more issues.

Kathryn Porter, an independent energy consultant, said: ‘The more you have wind and solar on the grid, the less stable the grid becomes and so the harder it is to manage faults.

‘I would say there’s a strong chance that the large amount of solar on the system created the conditions for this to be a widespread blackout and made it much worse.’

Traditional generators, like coal and hydroelectric plants or gas turbines, are connected directly to the grid via heavy spinning machines that store inertia, which acts as a shock absorber, protecting against any supply disruption due to changes in electrical frequency.

Ms Porter added: ‘When you are in a low-stability situation, it’s much harder to control what happens. Electrical things don’t like big changes in frequency and shut themselves down. They all start tripping off.

‘So, your grid operator will have been sitting there, trying to react to the changes in frequency, but they can’t do it fast enough. So that causes a cascading grid failure.’

A Police car officers is parked under switched-off traffic lights during a power cut affecting the entire Iberian peninsula and the south of France, in Madrid on April 28

Millions were left without power as public transport and roads ground to a halt

A closed petrol station in Villabona on April 28, 2025, during the massive power cut

Residents in Spain reported differing levels of reception, with power being partially restored through the day.

Loxone, a company providing backup power during grid failures, said homes protected by its technology continued to operate ‘seamlessly’ as others were plunged into darkness.

As mains electricity and internet were cut off, leaving locals confused as to what was happening, a few protected homes stayed lit and secure, with lighting automatically dimmed to extend battery life, a spokesperson said.

In neighbouring Portugal, visitors said the country still felt ‘like being back in full lockdown’ after parts were knocked offline, and supermarkets raided for supplies.

‘Supermarket shelves [are] empty already,’ one told MailOnline. ‘No one seems to be aware of exactly how long this will last, which seems to [have] created panic.’

Airports have also been hit by the outages, with flights delayed and cancelled.

At Francisco Sá Carneiro Airport in Porto, many travellers pitched up for the night after waiting hours for news on their flights.

Airlines had warned travellers of disruption, with one major carrier, TAP, advising flyers not to come to the airport at all.