The Iberian blackout of April 2025: what happened and what it teaches us
On 28 April 2025, at about 12:33 CEST, mainland Spain and Portugal lost power within seconds. Portugal’s transmission grid was restored by 00:22 the next morning and Spain’s by about 04:00, roughly 12 and 16 hours later. Trains stopped, traffic lights went dark and mobile networks became patchy. The households that coped best had a battery radio, cash, water, light and a charged power bank.
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What happened on 28 April 2025
Shortly after 12:32 CEST, voltage in the south of Spain rose sharply. Generators began disconnecting to protect themselves, which pushed voltage higher still, and within seconds the Spanish and Portuguese systems lost synchronism with the rest of the continental European grid and collapsed. The Balearic and Canary Islands, which run their own systems, were not affected.
Grid operators Red Eléctrica (Spain) and REN (Portugal) started their restoration plans immediately, with help from connections to France and Morocco. According to the expert panel convened by ENTSO-E, the European association of grid operators, Portugal’s transmission grid was fully restored at 00:22 on 29 April and Spain’s by about 04:00. For most households the outage lasted from early afternoon to late evening or the night.
What caused it?
The expert panel’s final report, published on 20 March 2026, concluded that there was no single cause. It describes a combination of interacting factors: two episodes of oscillations in the half hour before the blackout, gaps in voltage and reactive-power control, renewable plants operating at a fixed power factor, manually operated shunt reactors, and overvoltage protection settings that tripped generators in a cascade. The report makes technical recommendations for grid operators; for households, the lesson is simpler. Modern grids are very reliable, but when they fail, they can fail fast and over a huge area.
What stopped working
| System | What people experienced | What helps at home |
|---|---|---|
| Mobile phones and internet | Patchy calls and data as networks lost power and backup ran down | Battery radio; paper contact list; power bank |
| Card payments and ATMs | Many shops could only take cash, if they opened at all | Cash in small notes |
| Trains and metros | Passengers stuck in trains and tunnels for hours | Water, a snack and a torch in your daily bag |
| Traffic lights | Gridlock in big cities | Avoid driving; plan to walk home |
| Lifts and water pumps | People trapped in lifts; low pressure on upper floors | Stored water; know your building |
| Fridges and freezers | Food at risk after a few hours | Keep doors shut; eat fridge food first |
Spain’s mobile alert system, ES-Alert, was also affected: Spanish media reported that a failure of the Interior Ministry’s platform prevented seven regions from sending alerts during the blackout. Broadcast radio, on the other hand, kept working, and battery radios became the most valuable gadget in many homes.
10 lessons for your household
- Have a radio that doesn’t need mains power. A battery, crank or solar radio is the one item every agency puts on its list. Read our emergency radio guide.
- Keep cash at home. Small notes and coins, enough for a few days of food and transport. See how much cash to keep.
- Keep phones and power banks charged. Make it a habit to top up your power bank once a month. A 20,000 mAh bank gives several phone charges; our power bank guide explains sizes.
- Carry a mini-kit every day. A small bottle of water, a snack, a pocket torch and your medicines make an afternoon stuck on a train far easier.
- Agree a plan with your family in advance. Where do you meet if phones are down? Who picks up the children from school?
- Store water, especially in flats. Electric pumps lift water to upper floors; without them pressure can drop. Store at least 9 litres (2.4 US gal) per person.
- Use safe light. LED lanterns and head torches, not candles. Fire services in many countries warn about candle fires during outages.
- Protect the fridge. Keep doors closed: food stays cold for about 4 hours in a fridge and about 48 hours in a full freezer.
- Know who depends on electricity. Neighbours using oxygen concentrators, CPAP machines or electric wheelchairs need a backup plan. A portable power station can bridge many hours.
- Don’t call emergency numbers for information. Keep 112 free for real emergencies and get news from the radio.
What to buy after the Iberian blackout
None of these items is expensive, and together they turn a frightening afternoon into an inconvenience.
| Product | Best for | Key spec | Buy |
|---|---|---|---|
| Crank and solar radio | Every home | Works without mains or mobile data | Check price on Amazon |
| LED lantern | Lighting a room | Battery-powered, no fire risk | Check price on Amazon |
| 20,000 mAh power bank | Phones for several days | Several full phone charges | Check price on Amazon |
| Head torch | Hands-free light | Stairs, cooking, lifts | Check price on Amazon |
| Portable power station (≈ 1 kWh) | Wi-Fi, fridge top-ups, medical devices | Charge from mains or solar | Check price on Amazon |
We don’t list prices because they change often. Use the button to see the current price on Amazon.
Would 72 hours have been enough?
Yes, comfortably. The Iberian blackout lasted less than a day for most people, which is exactly the kind of event the EU’s 72-hour recommendation is designed for. A household with the basics of the blackout kit could simply wait it out at home, informed and fed, while emergency services focused on people stuck in lifts, trains and hospitals.
For step-by-step actions during an outage, see what to do in a power blackout. If you live in Spain, our Spain guide covers ES-Alert, 112 and regional advice.
Questions people ask
What caused the Iberian blackout?
ENTSO-E’s expert panel, which published its final report on 20 March 2026, found a combination of factors: voltage oscillations, gaps in voltage and reactive-power control, and cascading overvoltage disconnections of generators in Spain, which led to the collapse of the Spanish and Portuguese systems within seconds.
How long did the blackout in Spain and Portugal last?
Restoration started immediately. The transmission grid was fully restored in Portugal at 00:22 on 29 April 2025 and in Spain by about 04:00, roughly 12 and 16 hours after the blackout. Some local supplies came back much earlier.
Were the Balearic and Canary Islands affected?
No. The islands run separate electricity systems and were not part of the mainland collapse.
Could a similar blackout happen elsewhere in Europe?
Large blackouts are rare, but grids everywhere can fail because of technical faults, storms, heat or deliberate attacks. That is why the EU recommends that households can cope on their own for at least 72 hours.
What is the single most useful item in a blackout?
A battery or crank radio. When mobile data and the internet are unreliable, broadcast radio is how authorities reach people.
Keep reading
- /what-to-do-in-a-power-blackout/
- Best emergency radio: crank, solar and battery
- How much cash to keep at home, and which documents to copy
- Spain: the 72-hour emergency kit after the blackout
Sources
- ENTSO-E: 28 April 2025 blackout in Spain and Portugal, expert panel reports
- European Commission (DG ECHO): EU Preparedness Union Strategy, 26 March 2025
- Spain, Civil Protection: ES-Alert public warning system
- Ready.gov (FEMA): Power outages
- ENTSO-E Expert Panel, final report press release, 20 March 2026
- El Mundo, report on the ES-Alert platform failure, 9 May 2025
- La Vanguardia, Catalonia’s 72-hour kit campaign, 18 November 2025