In nearly 40 years as a shopkeeper, James Daunt has had to deal with power cuts many times. “Sometimes there’s a flood or a huge JCB digger has gone through your power supply,” says the founder of Daunt Books, and managing director of Waterstones. “You might run the power from the guy next door, or sometimes you’re literally going round with a torch collecting books for customers in the gloom.” But this winter could present a very different challenge. If gas supplies run too low, the government has crisis plans for a series of rolling three-hour power cuts, with regions of the UK taking it in turn to go dark. This week, the Guardian revealed that officials have also dusted down Programme Yarrow, which would kick in if there were a complete nationwide blackout. It involves prioritising food, water and shelter for the young and for older people, and examines how to communicate with the public. Only hospitals, oil refineries and certain other critical services would be protected. One of the last big power cuts, in August 2019, hit a million customers’ electricity supplies, and caused chaos for rail, road and air commuters. Shop tills froze, IT systems crashed and factories shut down. Thousands of bosses across the country are working out how to prepare their businesses for the worst-case scenarios. In retail, ensuring that stores can still trade is prioritised. Waterstones’ till systems are backed up with uninterruptible power supply (UPS) units, which can work offline. “When the power comes back, all the money flows through,” says Daunt. “The UPS units cannot provide enough power for adequate lighting but you carry on in the gloom – customers are very tolerant of it.” At other shops without these backups, transactions become near impossible in an increasingly cashless economy. As the threatened three-hour blackouts are designed to be evenly spread across the country, Daunt believes that it could be “swings and roundabouts” for his 300 stores nationwide, depending on where and when the cuts fall. For supermarkets – with huge supply chains, chillers and lighting requirements – energy is a huge resource. Sainsbury’s this week said it can control ventilation and lighting in stores and can be “very agile” in responding to issues, although it is not stocking up on generators for each store. Waitrose says the “vast majority of our main buildings have secondary power supplies”. Iceland’s boss, Richard Walker, says the retailer is “in the process of mapping out our future energy requirements” and is installing solar panels at its shops and warehouses. He concedes, however, that nationwide blackouts would make it difficult to keep shops open. In the City, where lost trading time could cost millions of pounds, catastrophe protocols are being studied. Banks in London may use locations beyond the Square Mile, mainly in Essex and Surrey, which were called upon in the pandemic. JPMorgan has said it has contingency plans for all its locations, and can even move staff between offices in different countries. The trade body UK Finance says firms are “making sure their ducks are in a row” and studying precedents in markets such as South Africa, where power cuts are commonplace. Typically, City firms have at least 72 hours of backup generator power, as well as on-site engineers. Industries where being efficient with time is crucial are particularly exposed to power cuts. A senior newspaper executive says it has a “Mary Celeste-style” empty office far from its central London newsroom to ensure it can continue to publish in an emergency on tight deadlines. The site has capacity for about 30 core editors and production staff. “The office is meant to be used in the case of some form of disaster. It has a backup generator, which is tested regularly,” he says. “Improvements in technology allowing people to work from home have made it slightly less important – the key is to have remote access to your core system and protect your server.” Home working will be reliant on robust telecoms, but this is an industry used to outages, typically caused by problems such as storms, and falling trees hitting overhead lines. BT operates 6,000 UK exchanges, each of which has a backup generator. Simon Lowth, BT’s chief financial officer, said this week it has held talks with the government about potentially using the generators for wider public use “to help cope with demand at peaks”. Its ubiquitous green cabinets, seen on Britain’s street corners, which provide broadband connections, have four hours of backup power. The British Gas owner Centrica advises businesses that, rather than protect an entire site from electricity loss at huge cost, they should prioritise essential systems. Certain industries simply cannot function in darkness: blackouts in the West End in 2016 forced performances to be scrapped at some of the country’s best known venues. Some consumers have begun contingency planning. Demand for airfryers, electric blankets and energy monitors had already soared as shoppers sought to cut bills. Now, Google Trends data shows a sharp increase in searches for portable power packs and torches. The slightly apocalyptic scenario has also piqued the interest of survivalists, or “preppers”, who proactively prepare for emergencies. A Reddit discussion among preppers on the prospect of UK blackouts shows users encouraging each other to buy bio-ethanol fires, USB-powered electric blankets, dry pre-packaged meals, water filters and plumbing supplies in case pipes freeze. One senior energy executive says: “The more remote your house is, or the more essential a service your business provides, the more robust your plans for power loss should be.”