Long power outage (blackout): how to prepare and what to do

On 28 April 2025, Spain and Portugal lost power for most of a day. Trains stopped, traffic lights went dark, card payments became impossible and millions of people discovered how much everyday life depends on the socket in the wall. Grid-wide blackouts like that are rare, but local outages lasting hours or days, caused by storms, ice, heatwaves or wildfires, happen every year almost everywhere.

What stops when the power goes

Not just the lights. Think of everything that depends on electricity:

• Heating: gas boilers need power for the pump and ignition.
• Water: pressure pumps in apartment buildings and some pumping stations stop.
• Communications: the router dies immediately; mobile masts have batteries for a few hours, then may go down.
• Money: cash machines and card terminals stop working. Gas stations can’t pump fuel.
• Fridge and freezer.
• Elevators. If you’re trapped, press the alarm button and call the emergency number or the maintenance company shown in the car.

Before: what to have at home

• A flashlight for each member of the household and spare batteries
• One or two LED lanterns for rooms
• Charged power banks
• A battery or wind-up radio
• Water for at least 3 days (4 liters per person per day)
• Food that needs no cooking
• Cash in small notes
• Blankets and warm clothes, in winter
• A fridge thermometer
• The car tank at least half full

For long outages, consider a portable power station, possibly with a solar panel.

In the first minutes

1. Check whether it’s just you. Look out of the window: if the neighbors have light, the problem is probably your fuse box or your building’s.
2. Report it to your electricity network operator (the number is on your bill or their website) if the outage is local.
3. Unplug sensitive appliances (computers, TV, large appliances). Power surges when the electricity comes back can damage them.
4. Leave one light switched on so you know when the power returns.
5. Keep the fridge and freezer closed unless absolutely necessary.

The first 24 hours

• Save your phone battery: turn on battery saver, lower the brightness, close apps and text instead of calling.
• Get your information from the radio, not from rumors.
• Use flashlights, not candles. If you do light candles, put them on stable surfaces, away from curtains, and never leave them unattended.
• Check on neighbors, especially older people and anyone who depends on medical equipment.

Food in the fridge

The timeline above shows the usual limits; enter the time the power went out to see the exact deadlines.

• A closed fridge keeps a safe temperature (below 4°C / 40°F) for about 4 hours.
• A full freezer, kept closed, holds for about 48 hours; half-full, about 24.
• Eat the fridge food first, then the freezer food, and only then your non-perishable supplies.
• In winter you can keep food outside in a closed box if the temperature stays consistently below 4°C.

If the outage lasts several days

In winter: gather in a single room, the smallest and most sheltered. Cover the windows with blankets or foil, put a towel along the bottom of the door, dress in layers and sleep together. Read how to heat your home safely without power.

In summer: keep windows closed and blinds down during the day and open them at night. Drink often and watch for signs of overheating, especially in children and older people.

Cooking: use a camping stove only on an open balcony or outdoors. See cooking without power.

Safety above all

Carbon monoxide has no smell and no color. Never use a generator, charcoal grill, camping stove or a gas heater not designed for indoor use inside your home, garage or an enclosed balcony. Symptoms (headache, dizziness, nausea, drowsiness) come on gradually and can be mistaken for tiredness.

If you use a generator, keep it outside, several meters from doors and windows, and never connect it directly to your home’s wiring without a transfer switch installed by a licensed electrician: you could electrocute the workers repairing the grid.

When the power comes back

Wait a few minutes before plugging appliances back in, then switch them on one at a time. Check the fridge temperature and throw out anything no longer safe. Recharge your power banks, flashlights and power station straight away, ready for next time.