AI & infrastructure
AI, cyber-attacks and the grid: what a modern blackout looks like
Nobody serious expects a robot uprising. The UK's cyber agency does expect AI to make attacks faster and more frequent, and modern life fails in a predictable order when the systems stop.
What the agencies actually say
The most useful source in Britain is the National Cyber Security Centre, part of GCHQ. In January 2024 it published its assessment of the near-term impact of AI on the cyber threat. Its central judgement: AI will almost certainly increase the volume and heighten the impact of cyber-attacks over the following two years, with different kinds of attacker benefiting in different ways.
In May 2025 it looked further ahead, to 2027. That second assessment judged that AI will make parts of cyber intrusion more effective and efficient, and that building AI into the UK's technology, including critical national infrastructure, widens the surface attackers can target. Systems that do not keep pace, it warned, will become more vulnerable.
That is the sober version of the AI risk for households: not a machine deciding to switch off the lights, but more capable attackers probing the systems that keep power, water, payments and communications running.
What has already happened
Cyber-attacks have already turned off the lights. In December 2015, attackers took over control systems at electricity distributors in western Ukraine and cut power to hundreds of thousands of people: the first confirmed blackout caused by hackers.
Large blackouts also happen without anyone attacking anything. On 28 April 2025, the grids of mainland Spain and Portugal collapsed in seconds. Europe's grid operators found a cascade of interacting failures: oscillations, gaps in voltage control and generators disconnecting one after another. Power returned to most homes by the next morning, but for hours trains stopped, traffic lights went dark, card payments failed and phones lost signal.
The lesson for a household is the same whatever the cause. It does not matter much whether a blackout starts with a criminal gang, a software fault or a storm. What matters is what you have at home when it happens.
The order things fail
Modern life runs on electricity and networks, and they fail in a fairly predictable sequence.
| When | What stops |
|---|---|
| Minutes | Lights, most gas central heating (the boiler needs power), lifts, traffic lights, card machines, broadband and digital landlines without battery back-up |
| Hours | Mobile signal, as masts' back-up batteries run down; fuel pumps; chilled food in fridges; cashpoints |
| Days | Water pressure in places that depend on pumping; supermarket shelves, which run on just-in-time deliveries; anything that needs a network to order or pay |
What it means at home
- Water: sealed water for the first day and a way to treat more.
- Heat and light: layers, blankets, head torches and lanterns. No gas heaters indoors.
- Power: power banks at minimum; a power station with solar for longer outages.
- Information: a wind-up radio, and printed copies of the numbers, documents and maps you would normally keep on your phone.
- Money: some cash in small notes.
- A plan: where the family meets, who checks on elderly neighbours, what you do if you have to leave.
- Signal hygiene: a signal-blocking pouch keeps a spare phone and car keys isolated, which is useful against relay car theft every day and against interference in a crisis.
Keeping perspective
Britain's electricity system is among the most reliable in the world, and a long national blackout is unlikely in any given year. That is the point of preparing: it is cheap relative to the disruption it prevents, and it means that if the worst week of the decade does arrive, your household spends it calmly at home rather than queueing for water.
Preparing is not pessimism. The Government asks every home to do it. We just think it should be done properly.