Massive power failure in Spain (April 28, 2025)
- Fénix Digital Technology Digital Agency
- Apr 29
- 18 min read
On April 28, 2025, Spain experienced a sudden power outage, causing disruptions to water, internet and communications. Find out what caused the crisis.
Situation Overview
On April 28, 2025, Spain faced an unprecedented infrastructure crisis - a sudden large-scale power outage, causing water outages and disruptions to internet and communications. At around 12:33pm local time, the country's power grid experienced a dramatic generation collapse: in just five seconds, about 15GW of power fell off the grid, accounting for ~60% of all electricity generated at the time.
As a result, almost the entire mainland of Spain and neighboring Portugal were left without power. This was the largest blackout in Spain's recent history, instantly paralyzing transportation, communications, businesses and institutions. Millions of residents across the country - from major cities (Madrid, Barcelona, etc.) to rural areas - were suddenly plunged into darkness. Normal activities like turning on lights, using appliances, and trying to make cell phone calls or access the internet became impossible.
The population and infrastructure were unprepared for such a large-scale blackout. Immediately after the blackout, transportation and utilities began to malfunction: rail, subway and train services stopped, traffic lights stopped working, and there was chaos on the roads and at airports.
Emergency services and hospitals switched to backup generators to keep vital systems running. Many residents, without their usual sources of information, switched to battery-powered radios to catch up on the news. Authorities estimate that this emergency power outage was one of the worst episodes in decades, affecting tens of millions of people.
Regions affected and scale of the outage
15 autonomous communities of mainland Spain
The accident was of a pan-Hispanic nature - almost all 15 autonomous communities of mainland Spain were affected. Complete de-energization occurred throughout the continental territory of the country: from Galicia and the Basque Country in the north to Andalusia in the south, from Catalonia and Valencia in the east to Extremadura in the west.
Portugal
Portugal also joined the outage - the Iberian Peninsula's unified power grid led to the blackout spreading to Portuguese regions, including the capital Lisbon.
Madrid
Capital Region Madrid, Barcelona and other major cities were simultaneously plunged into darkness, bringing metro, electric transport and elevators to a standstill.
Administrative offices, schools, and stores were all forced to shut down in the middle of the day. Residents of major cities poured into the streets on foot, trying to get home or to their children's schools, creating crowds of pedestrians unusual for a weekday.
Balearic and Canary Islands
At the same time, a number of regions remained out of the blackout zone. The Balearic and Canary Islands and the cities of Ceuta and Melilla in North Africa were not affected, as their power grids are isolated from the Spanish grid.
France
In addition, it was reported that there was only a brief power failure in southern France (in areas bordering Spain), which was quickly resolved by the French operator RTE telemadrid.es. The French grid automatically disconnected from the emergency Iberian unit, avoiding widespread consequences; the French operator then confirmed its willingness to provide Spain with up to 950 MW of capacity via interconnectors to assist in restoration. Thus, the Iberian Peninsula was hit hardest, covering virtually the entire Iberian grid.
Emergency regime in the regions
The Spanish government promptly declared a state of emergency (regime of “national emergency”) in the most affected regions. By the evening of April 28, such a national “state of emergency” was introduced in five autonomies that had requested assistance from the center: Madrid, Andalusia, Extremadura, Murcia and La Rioja.
Later, Galicia, Castile-La Mancha and Valencia declared the need for a state of emergency. In these regions, the Spanish Ministry of the Interior took over the coordination of liquidation of the blackout consequences. At the same time in Portugal, the National Coordination Center for Emergency Situations was convened, where the country's emergency services were united. The governments of both Spain and Portugal utilized all available resources to restore power and water supply, communications and order as soon as possible.
Possible causes of the incident
The exact reasons for such a large-scale failure remain unclear as of the evening of April 28. Spanish government officials emphasize that the situation is unprecedented and requires a thorough investigation:
"Never before has the system dropped to zero. Specialists have not yet been able to determine the causes, but will definitely find out," said Prime Minister Pedro Sanchez, noting that all possible versions of what happened, including a cyberattack, are being considered.
Authorities refrained from drawing any conclusions in the morning; Sanchez urged citizens not to panic and to focus only on official information to avoid spreading rumors and misinformation. “We will not speculate,” his administration emphasized, commenting on the lack of data on the cause of the unexpected “energy zero” in the network.
According to preliminary technical data from operator Red Eléctrica de España (REE), the accident began with powerful fluctuations in the electricity grid due to a sudden loss of generation. At 12:32 pm, a “very strong oscillation of power flows” was recorded, associated with the dropout of a large part of the generators.
This led to an unbalance and collapse of the system, after which automation kicked in: the Spanish grid disconnected from the European grid to localize the problem. In fact, the energy systems of Spain and Portugal were instantly isolated (“island” mode) and lost the lion's share of their energy sources. Such a scenario had never been realized in practice before, which caused confusion among experts.
“In 40 years in the industry, I have never seen anything like this,” notes former Red Eléctrica president Jorge Fabra. Officials recognize that an incident of exceptional scale and rare in nature has occurred, the likelihood of which was considered negligible. Now the fact of a sudden “power zero” on the national grid raises questions about the vulnerability of the infrastructure and whether it could happen again in the future .
In the absence of confirmed causes, various hypotheses of what happened started to appear in the media and expert community. Let us consider the main versions voiced by the end of the day on April 28 and the attitude of officials and experts to them:
A version of a natural phenomenon
One of the first hypotheses to emerge was that of some anomalous natural phenomenon affecting the power grid. In the report of Reuters with reference to the operator of the Portuguese power grid REN suggested that the cause of the blackout could be “extreme temperature fluctuations in central Spain”, which caused “induced atmospheric vibrations” of power lines.
According to this theory, strong vibrations of transmission line wires (e.g., due to temperature spikes or wind) could have disrupted the synchronization of power systems, leading to an avalanche-like failure of equipment throughout the grid.
However, this theory was soon disproved. REN representatives disavowed the earlier report, specifying that there was no specific data on the weather anomalous influence, and the mention of “sharp temperature variations” was not confirmed by observations.
Spanish scientists were also skeptical of the idea. “I rule out that it was an atmospheric phenomenon,” said astrophysicist Jose M. Madiedo of the Andalusian Institute of Astrophysics. He noted that neither weather stations nor satellites have recorded unusual spikes in temperature, pressure or hurricane-force winds that could support this hypothesis.
Even if such phenomena were to occur, it is highly unlikely that they could disable the entire system, the scientist added. Madiedo also compared the situation to the famous “Carrington event” - the most powerful solar storm of 1859 - which knocked out telegraphs around the world. However, he emphasized that a solar storm of this magnitude would have affected the entire world, not just Spain and Portugal, so he also rejects the version of a geomagnetic storm or other cosmic influence. Thus, the hypothesis of a natural (atmospheric or geophysical) cause of the mass failure is recognized as unlikely - neither weather conditions nor solar activity, judging by the data, could have caused such a localized and large-scale effect.
Version about cyberattack or sabotage
Against the background of general geopolitical tensions, speculation about a possible cyberattack on critical infrastructure quickly spread. Many recalled the scenarios of attacks on power grids (in particular, the well-known power outages in Ukraine in 2015-2016 associated with the activities of Russian hackers). Juan M. Moreno, head of the Andalusian government, was the first to publicly voice this version quite confidently, saying that according to the regional cybersecurity center, “everything points to the fact that a blackout of this magnitude can only be caused by a cyberattack.” He stipulated, however, that this assessment was made “based on Andalusia's own data” and was not confirmed by official Madrid.
Central authorities are treating the cyberattack version with caution. Pedro Sanchez emphasized that there are no conclusions yet and urged not to spread unconfirmed information. Vice-President of the European Commission Teresa Ribera (in charge of energy issues) in Brussels also stated that there are no signs of a deliberate impact - according to her, at the moment there is no evidence pointing to someone's malicious hacking of the energy system.
Cyberattack scenario
However, the authorities have not ruled out a cyberattack scenario and are investigating accordingly. Spain's National Cryptologic Center (an intelligence unit of CNI) and the Joint Command for Cyberspace of the Ministry of Defense have been instructed to thoroughly check digital systems for external interference. Similar checks have been initiated in Portugal: the Portuguese National Cybersecurity Center issued a communiqué by evening that there was no data linking the blackout to the cyber incident, but continues monitoring.
Cybersecurity experts note
Cybersecurity experts note that it would be extremely difficult to organize a hacker attack capable of plunging two major countries into darkness at once. It would require an unprecedentedly coordinated operation, simultaneously disabling multiple nodes of the power grid. “A blackout of this magnitude using a cyberattack would be extremely difficult because the power grid is segmented into many sub-networks,” explains cyberthreat expert Martin Vigo.
Even if an attack occurred, it will take time to identify and trace it in the networks, experts add: there may not be clear “fingerprints” that unambiguously indicate cyber intrusion. "Everything we have observed could well have happened for normal (unintentional) reasons. That's why it's important to investigate thoroughly and not give in to rumors," notes expert Lukasz Olejnik of King's College London. He points out that power systems are extremely complex and have many vulnerable points - theoretically, an attack is possible (for example, by affecting transformers and substations, which could damage equipment and cause a cascading failure).
However, it is extremely difficult to synchronize so many attacks at once to disrupt an entire network, and so far there are no concrete indications in Spain that such a scenario has occurred. No direct evidence of a cyberattack has been found, but the investigation of this version will continue until the authorities are fully confident.
Versions of technical failure
The most likely explanation is considered by many experts to be a combination of technical factors and equipment failures within the power system. Although details are scarce at the time of the incident, a picture of a chain reaction is gradually emerging: the sudden shutdown of one or more major energy sources (e.g., generators or lines) caused a frequency/load imbalance that led to emergency protection and the shutdown of other elements of the grid.
Such events, although extremely rare, are known from the experience of power systems in other countries (e.g., the major North American blackout of 2003 or the partial blackouts in Europe in 2006 and 2021). In this case, the outage was unusually rapid and widespread, taking automation systems and dispatchers by surprise.
As Solomon Brown, professor of energy systems at the University of Sheffield, pointed out, modern power grids are tightly interconnected through interconnectors, so a failure in one location can quickly affect others. However, after a complete blackout, the network has to be brought up segment by segment in isolation.
The black start process
The black start process involves gradually starting up key generators and connecting consumers in stages so that electricity production and consumption are always in balance. Brown explains that it can take hours to restore such a large grid, and if at any point the balance is out of balance, operators have to start over.
This was the challenge faced by the operators of REE and Portugal's REN on the afternoon of April 28, requiring the entire grid to be restarted virtually from scratch. This process in itself is extremely difficult, but the Spanish power engineers noted that “nothing is out of the ordinary - these are standard procedures in case of such accidents,” and they were immediately put into action.
The main working version of the causes
Thus, the main working version of the causes is purely a technical accident (e.g., equipment failure or automatic errors), without external intervention. It is indirectly confirmed by the first assessments of the Portuguese side: Portuguese Prime Minister Luis Montenegro said that “everything points to the source of the problem in the connection line with Spain”, in fact naming the Spanish segment of the power grid as the epicenter of the failure.
Montenegro also emphasized that he saw no signs of malicious influence and that the two governments were working closely together to deal with the accident. Officials and independent experts agree that the final conclusions about the cause of the blackout will be made after a detailed investigation.
A large amount of telemetry data, event logs of power companies and the state of the equipment will have to be analyzed. At the moment, the authorities are deliberately refraining from making any definite statements as they continue to test all possible theories - from a complex cascading technical failure to potential sabotage or cyberattack.
Impact on Infrastructure and Population
The massive power outage on April 28 had an immediate impact on all major infrastructures, from transportation and communications to water supply and commerce. The key impacts of the blackout are discussed below:
Power Supply and Energy. In the first seconds and minutes of the accident, power utilities saw a precipitous drop in consumption: from ~25,000 MW to ~12,400 MW telemadrid.es, indicating a total shutdown of a large part of the grid. Substations and transmission lines across the country were de-energized, plunging towns and villages into darkness. The total blackout lasted several hours - according to authorities, Spain and Portugal were actually without central power for about 7-8 hours.
This time was characterized by almost complete cessation of usual life: enterprises did not work, public transport stopped, stores and institutions were closed. Many residents compared what was happening to apocalyptic scenarios. For example, in the center of Barcelona, anxious citizens asked: “Is it the end of the world?”. Spanish media called what happened “an energetic September 11,” emphasizing the shock and scale of the disaster.
Transportation collapse. A power outage paralyzed the transportation system
In Madrid and Barcelona, subways were completely shut down - trains were stuck in tunnels, evacuation of passengers along the tracks was required elpais.com.
Suburban trains and intercity railroads also stopped running for hours, leaving tens of thousands of people stranded en route or at stations. It was not possible to restart rail service until late Monday afternoon, even with power returning - requiring time to check systems and position trains on schedule.
Street traffic faced chaos: traffic lights did not work, which led to kilometer-long traffic jams. In Barcelona, volunteer citizens themselves tried to regulate traffic at intersections.
Airports switched to backup power; although flight safety was ensured, traffic near the airports became more difficult - hundreds of people in Madrid, who missed their flights because public transportation stopped, tried to catch hitchhikers to the airport, standing with makeshift signs on the road.
Gas stations also shut down due to a lack of power for fuel pumps, which could complicate transport and emergency services if the crisis drags on.
Communications and Internet
A blackout disrupted communications across the country. In the first few minutes, cell phones and the Internet were still working thanks to uninterrupted power supply at communication nodes, but as backup batteries ran out, communications began to disappear. Large data centers and backbone network nodes have diesel generators and can withstand long outages. However, the local communications infrastructure - thousands of city nodes, mobile towers, switches - are designed for only a few hours of autonomous operation, so they were gradually shut down during the large-scale outage.
As telecommunications expert Arturo Ascorra (IMDEA Networks Institute) noted, the Internet network can be compared to a nervous system: even if the “brain” (central nodes) is functioning, the failure of the “peripheral nerves” (local switches) makes communication impossible. That's exactly what happened: mobile communications and wired internet in most of Spain stopped working. Operator Vodafone reported around 15:00 that thanks to backup generators about 70% of their network is still functioning, but warned that the network depends on the duration of the outage.
By late afternoon, however, a large proportion of cell towers had run out of battery power, and it was impossible to call or text in most parts of the country. Only occasionally did some people manage to get a weak signal or connect to Wi-Fi where there were autonomous power sources (e.g., in buildings with generators). Operators urged citizens to conserve phone power and only use their phones in emergencies to avoid overloading surviving network segments.
In fact, Spain was back in the analog era - without the Internet and mobile telephony, many people reverted to radios and corded phones (where they had them). This sudden “digital silence” was one of the most tangible consequences of the blackout for the population.
Water Supply and Other Utilities
While there is no direct connection between the power grid and the water supply, the lack of electricity has also hit the water supply. Water utilities and pumping stations that pump water to cities and maintain pressure in the pipelines stopped without power. As a result, water pressure began to drop in some areas, especially on the upper floors of high-rise buildings and in remote communities dependent on electric pumps.
According to local authorities, there were no serious disruptions in drinking water supply, as reservoirs and uninterrupted supply systems were able to maintain the flow for some time. Nevertheless, the population began to stock up on water just in case. There was an increased demand for bottled water in the stores - people bought bottles, fearing a long absence of central water supply.
In major cities (e.g. Barcelona), supermarkets reported that customers were primarily taking water, canned food, candles and toilet paper to form an emergency stockpile. This suggests that the population perceived the power outage as a potentially long-term disaster and prepared for the possibility of being without basic amenities (light, water, heat) for some time.
In addition to water, garbage collection and other city services that depend on electricity (e.g., street lighting, elevators, etc.) stopped. Utilities in the emergency situation switched to an emergency action plan, trying to prioritize the most critical needs (e.g., water and fuel supply for generators to hospitals, etc.).
Social consequences and citizens' behavior
The mass blackout caused mixed feelings of panic and solidarity among people. On the one hand, there were elements of frenzy - as already mentioned, residents bought long-stored food and essentials, fearing a prolonged crisis. In some places there were queues for bread, canned goods, batteries and candles.
On the other hand, there were no cases of rioting or looting - security was maintained by reinforced police patrols and civic responsibility. In major cities, additional law enforcement forces worked to prevent crimes in the dark and regulate traffic conditions.
Many citizens helped each other: drivers gave unfamiliar hitchhikers a ride home; neighbors in high-rise buildings offered water and flashlights to elderly people and helped them down stairs. The ordeal confirmed the community's cohesion in the face of the disaster. Nevertheless, life in the country virtually came to a standstill for the day - the workday was disrupted, schools and offices were closed, and institutions were not functioning.
Authorities' Response and Recovery Forecast
The Spanish government and responsible services responded quickly to the emergency, deploying a plan to restore the system and inform the public. As early as the afternoon of April 28, Prime Minister Sánchez arrived at REE's National Control Center, from where restoration efforts were coordinated.
An emergency meeting of the National Security Council was convened in Madrid, attended by King Philip VI (the meeting was scheduled for the morning of April 29). The government issued a series of appeals to citizens to remain calm and use available resources (water, flashlights, battery power) sparingly until power returns.
Military and civil protection generators and transport were mobilized to assist the most vulnerable groups (hospitals, nursing homes, patients on life support). In particular, strategic fuel reserves were partially released: the government ordered a three-day reserve stock of petroleum products to refuel generators and meet energy needs. This step was to support emergency services until the centralized electricity supply was restored.
Restoration of the power system
Restoration of the power system started almost immediately after the blackout - grid operators started a phased “restart” of generation. Already ~2 hours after the blackout started (by ~15:00), REE experts predicted that it would take 6 to 10 hours to fully restore power supply. This forecast was based on calculations of phased commissioning of capacities and harmonization of network operation.
The first encouraging news appeared ~5 hours after the start of the accident: in some areas in the north and south of Spain, electricity began to appear around 17:30. According to Red Eléctrica, power supply has partially returned in parts of Catalonia, Aragon, Basque Country, Galicia, Asturias, Navarra, Castile and Leon, Extremadura and Andalusia. A couple more hours later (~7 hours after the outage), isolated points in Valencia, Cantabria, the Community of Madrid, La Rioja, Murcia and Castile-La Mancha were added to the list of restored points.
Thus, by evening, electricity began to be supplied at least partially to all affected autonomous communities of Spain. Restoration went unevenly - somewhere the light came on earlier, somewhere people remained without power longer, waiting for the inclusion of their segment of the network.
By late evening, the situation had improved significantly. At 22:30-23:00 Pedro Sanchez gave his second address of the day and said that almost 50% of the country's power supply had already been restored. “There is an improvement in almost all autonomies.”
Школы в затронутых регионах на 29 апреля 2025
Вместе с тем власти решили подстраховаться на случай продолжения перебоев на следующий день: было объявлено, что 29 апреля школы в затронутых регионах будут открыты, но занятия проводиться не будут, чтобы родители могли выйти на работу, а дети находились под присмотром. В Мадриде и Арагоне, например, во вторник школы работали в режиме продлёнки без уроков, тогда как в Галисии власти вовсе отменили занятия, а в Андалусии решили провести уроки в обычном режиме.
Одновременно городские власти крупных городов подготовились к утру: в Мадриде проезд на муниципальных автобусах 29 апреля сделали бесплатным на случай, если метро ещё не полностью восстановит движение.
Predictions of full restoration of systems
Predictions of full restoration of systems were optimistic. Portuguese Prime Minister Luis Montenegro told the press on the evening of April 28 that he had called Sanchez several times and “expects power to be restored by the end of the day.” This prediction generally came true - by midnight, much of Spain and Portugal already had light. There remained localized outages in particularly problematic nodes, but they were planned to be eliminated in the next few hours of the night.
As of the morning of April 29, authorities expected power to return for the vast majority of consumers, although they warned that there could be localized outages or planned rolling blackouts if the balance was unstable. Communications companies also reported that with the return of electricity, mobile communications and the Internet would gradually resume operations, although it would take time to restart hundreds of nodes and base stations. By Tuesday morning, Internet connections began to be restored along with the power supply to network equipment, and major telecom operators planned to return services to normal during the day.
Water Supply
For water supply and other utility systems, the outlook was for power to be restored. Once electricity was returned to the pumping stations and treatment plants, water supply normalized. Serious impacts to the water system were expected to be avoided, limited to preventive flushing of mains in some areas after startup.
Nevertheless, utilities recommended residents to skip drinking water from the tap for a while or boil it for the first time before using it, in case of possible contamination due to pressure surges (this is a standard precautionary measure after shutdowns).
Thus, for April 29, the authorities predicted a gradual return to normalcy for the country. Already on the night of April 28/29, Spain began to receive power assistance from outside: neighboring France and Morocco supplied power through interconnections, speeding up the restart of the Spanish system. This cooperation made it possible to stabilize power supply in many regions faster than planned.
During Tuesday morning, traffic lights were working throughout the country, public transportation was restarted, and stores and institutions opened.
Rail service
Rail service returned close to noon on April 29 - trains and metros resumed service after infrastructure and signaling systems were inspected.
Mobile communications
Mobile communications largely recovered, although some operators reported localized damage to equipment that required repairs.
Power supply
Power supply is expected to be back to normal in almost all affected areas by the end of April 29.
Infrastructure Vulnerabilities
Despite the rapid recovery, the incident exposed critical vulnerabilities in Spain’s infrastructure. Experts urge that this blackout should serve as a wake-up call to revisit backup power protocols, strengthen the cybersecurity of national energy systems, and improve public awareness of emergency preparedness. It is already clear that a full audit of the power grid will be necessary, and some officials may be held accountable if preventive measures could have averted the crisis.
In the immediate aftermath, however, the top priority was restoring normalcy to everyday life. Both government officials and independent analysts agree that the socio-economic impact of the blackout is expected to be short-term. Within a day or two of the event, essential systems—electricity, water, communications, and transport—had resumed operation, though scheduling, education, and services still required some time to fully stabilize.
Spain’s Unprecedented Power Outage on April 28, 2025
The nationwide power outage on April 28, 2025, was unprecedented in scale and marked a serious stress test for Spain’s critical infrastructure.
The blackout affected nearly all of mainland Spain and extended into neighboring Portugal, disrupting electricity, water, and communications for tens of millions of people. Officials have described it as “one of the most severe infrastructure events in Europe in recent years.” Thanks to the coordinated response of utility providers, emergency services, and international support, core systems were partially restored by the end of the same day, with most of the country back to normal the following day.
Nonetheless, the root cause of the blackout remains under investigation. Authorities are exploring whether it was a purely technical collapse or if external interference—such as a cyberattack—played a role. Experts in energy, infrastructure, and cybersecurity have proposed multiple theories, from an extremely rare cascading equipment failure to the possibility of intentional sabotage. Conclusive findings will require time and thorough analysis.
Currently, the leading hypothesis is that the incident was technical in nature. However, its precise origin has yet to be determined. This crisis has highlighted the fragility of highly integrated modern power grids. In the near future, authorities are expected to implement stronger safeguards—ranging from enhanced redundancy and energy storage to improved cybersecurity measures across the network.
Despite the initial shock, Spain recovered remarkably quickly, demonstrating the government’s and public’s ability to mobilize in the face of an extraordinary emergency. Just 24 hours after the blackout, most regions had resumed normal life, while the incident itself became the subject of in-depth analysis aimed at ensuring such a systemic collapse is never repeated.
Sources: Official statements from the Government of Spain and Red Eléctrica de España (REE); reports from Spanish media outlets El País, EFE, and others; expert commentary from analysts in the fields of energy and cybersecurity (including Manuel Planelles, Jordi Pérez Colomé, Jorge Fabra, Lukasz Olejnik); and data from major telecommunications providers. This multifaceted collection of sources—ranging from government to independent experts—enabled a comprehensive assessment of the situation, an alignment of facts and theories, and a forecast for the system’s full recovery. Published by Fenix.info.
