How Long Would a Blackout Last? What Experts Say

This is the question that determines everything: How long do I need to be able to provide for myself? The answer is uncomfortable — but important.

Scenario / Duration	Infrastructure condition	Impact on you	Wolf’s unvarnished verdict
1. The ‘brownout’ (a few hours)	Local power cut / overload	The fridge stays cold; mobile network is patchy but hasn’t completely cut out yet.	“No need to panic. Power usually comes back on after 2 to 4 hours. Check your batteries anyway!”
2. The system collapse (24 to 72 hours)	Widespread blackout across the DACH region	Water supply cuts out, supermarkets close, mobile phone masts go down after 2 hours at the latest.	“The authorities’ official baseline scenario. Anyone who doesn’t have a self-sufficient supply of water and cooking facilities for these critical 3 days will immediately descend into chaos.”
3. The infrastructure collapse (1 to 2 weeks)	Cascading failures during grid restoration	Complete standstill of public life. Supplies only available via emergency collection points.	“The ultimate test for the state. This is where the wheat is separated from the chaff. Only those who have stockpiled supplies for at least 10 to 14 days will safely survive this phase.”

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Normal power cuts vs. a genuine blackout

A normal power cut following a storm or technical fault: lasting from minutes to a few hours. Everyone is familiar with this. It requires no major preparation.

A genuine, widespread blackout is fundamentally different. Here, it is not just a single line that collapses — but the entire interconnected grid. Restoring power is exponentially more difficult.

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Why the power grid is so difficult to restore

The European interconnected grid is highly complex. A restart following a total collapse — the so-called “black start” — takes hours to days, even if there is no further damage.

The problem: power stations need electricity to start up. This must come from special ‘black start-capable’ power stations that can start themselves. Then, more and more power stations and grid sections must be synchronised step by step — it’s like a gigantic jigsaw puzzle.

According to German grid operators: a controlled restart of the German grid takes 24–72 hours in the best-case scenario.

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What if there is damage?

If transformers, substations or power lines are physically damaged — through sabotage, natural disasters or cyberattacks — the duration increases dramatically:

• Large transformers have lead times of 12–18 months
• There are very few spare units in stock worldwide
• Specialists for these repairs are scarce

In its worst-case scenarios, the BBK plans for outages of up to 4 weeks.

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Historical comparisons

Event	Duration	Cause
Puerto Rico Hurricane Maria (2017)	11 months in parts	Infrastructure damage
North America Ice storm (1998)	5–25 days regionally	Power line damage
Texas winter storm (2021)	4–7 days	Infrastructure failure
Europe near-collapse (2006)	Minutes (averted)	Cascade effect
Ukraine cyberattack (2015)	1–6 hours regionally	Hacker attack

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What does this mean for your preparations?

Realistic scenarios:

• Technical fault without damage: 24–72 hours → Minimum stock sufficient
• More complex failure with partial damage: 1–2 weeks → Extended stock required
• Severe infrastructure damage: weeks to months → Long-term preparation

The BBK recommends: a 10-day supply as a minimum standard. This covers all realistic short-term scenarios.

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The right preparation depending on the scenario

Basic (72 hours): Water supply, food, torch, power bank
Extended (10 days): All of the above + gas stove, water filter, hand-crank radio
Long-term (4+ weeks): All of the above + balcony power plant, larger supplies, extended first-aid kit

👉 Blackout checklist: How to be fully prepared →
👉 Balcony power plant: Generate your own electricity →
👉 Emergency rucksack: Fully equipped for any blackout →