A clean grid with a gas bill

Energy-supply, industrial and cost-of-living risk for the United Kingdom through the winter of 2026 to 2027, across natural gas, electricity, oil products and the households and industries that run on them, assessed as at 16 September 2026.

Since 10 September, a Saudi oil pipeline that lets crude skirt the contested Strait of Hormuz has been shut by an attack, choking one of the routes that keep Gulf oil flowing to Europe while the strait itself stays disrupted. Loadings from the Red Sea port it feeds have stalled, and refiners across the continent have been scrambling for replacement barrels on the open market.

Britain barely felt the scramble. The United Kingdom buys very little Gulf crude, and almost all of its gas arrives by pipeline from Norway. On the face of it, the country that has decarbonised faster than almost any large economy, with a record share of wind and solar and its first full calendar year without any coal power, should be the one an oil war troubles least.

Yet British bills went up anyway. Wholesale gas is around 158 per cent higher than a year ago, petrol and diesel are at four-year highs, and the regulated cap on household energy has just risen again. The scramble was continental. The price was universal.

Here is the reason, and it is the spine of everything that follows. Britain's energy exposure does not run through the barrels it fails to receive. It runs through the price it pays for the gas that still sets its electricity bill, and through the near-empty cupboard it would have to draw on if a cold week met a supply shock. A clean grid does nothing to soften either. The danger this winter is cost and a shrinking margin of safety, not the lights going out.

The shock that reached the till, not the tanker

Everything in Britain's current energy position traces back to one waterway and the seven months since it closed. The Strait of Hormuz, the sea passage that carries roughly a fifth of the world's oil and a large share of its liquefied natural gas, has been disrupted since a US and Israeli war on Iran began on 28 February 2026. Britain ships almost nothing directly through it, but that is not the point. When the strait is contested, every barrel and every therm reprices, wherever it physically comes from.

The result is a set of numbers that look like a crisis and behave like one, without a single supply being cut. Brent crude, the global oil benchmark, traded near $107.50 a barrel in mid-September; wholesale gas hit about 205 pence a therm, up roughly 158 per cent on a year earlier and its highest since December 2022; petrol and diesel reached four-year highs, with the motoring body the RAC warning diesel could top £2 a litre.

That price has already reached the doormat. The regulator Ofgem raised the household energy price cap, the ceiling on what suppliers may charge a typical customer, by 4 per cent from 1 October, lifting the representative annual bill from £1,663 to £1,723 and hitting around 22 million homes, with the increase driven mainly by an 8 per cent rise in the gas element.

What is striking is what the people who run the system are not saying. National Gas reports no immediate operational concern, and the European Union's gas coordination group concluded in early September that there is no immediate security-of-supply risk despite low storage. This is the shape of the threat: acute on price, quiet on physical supply. It is a shock that arrives through the till, not the tanker.

The live signals, mid-September 2026

Signal	Where it stands	Context
Brent crude	about $107.50 a barrel	Near a four-month high
UK wholesale gas	about 205p a therm	Up ~158 per cent on a year earlier, highest since Dec 2022
Petrol	170.5p a litre	Highest since August 2022
Diesel	192.9p a litre	Highest since July 2022; RAC warns of £2
Gas storage	31 per cent full	Going into the winter refill season
Household price cap	£1,723 a year	Up 4 per cent from 1 October, ~22m homes

Note. None of these is a switch-off. Every one is a price, and every price is set in a market a war has moved.

Five pressure points, ranked by how hard they bite

1. The gas-set electricity price. This is the one that reaches everyone, and it is already here. Britain's grid is only about a quarter gas-fired by volume, but gas plants are usually the last unit needed at peak, and under the market's rules that final plant sets the wholesale price for everyone. So a grid that is mostly wind, solar and nuclear is still close to fully gas-priced at the moments that matter, and the Gulf gas surge flows into power bills the same day.

2. Europe's thinnest storage, and a looming cliff. The United Kingdom holds around 12 days of average gas cover, against 89 days in Germany, 103 in France and 123 in the Netherlands. Worse, the Rough field off Yorkshire holds most of what little Britain has, and its owner is on course to close it rather than reinvest. Lose Rough without a replacement and the cushion nearly disappears.

3. The Norwegian single point. Britain looks diversified but is not. Norway supplies 69 per cent of imported gas through undersea pipelines. Norway is a stable ally, so the risk is not politics but physical concentration: a serious fault or sabotage on that system, landing on a cold, still winter day, would remove Britain's largest single gas stream and force it to bid for replacement cargoes against the whole of Europe.

4. A refining base cut to four plants. In under two years Britain has lost a third of its oil refineries, the sites that turn crude into diesel, petrol and jet fuel, leaving four. Liquid fuels still supply 47 per cent of final energy, and in 2025 the country imported 15.5 million tonnes more petroleum products than it exported, the largest such deficit on record. Disruption to import terminals or shipping would strain diesel and jet fuel first.

5. The industrial slow bleed. The least dramatic and the most permanent. Even with state support, energy-intensive British industry pays more for power than its continental rivals, and steel, chemicals and fertiliser plants have been closing on energy cost alone. This is not a blackout. It is a one-way ratchet of curtailment, mothballing and exit, and what leaves this way does not come back when prices fall.

A green grid with a gas bill

Start with the achievement. In 2025 renewables supplied 47 per cent of UK electricity, the single largest source, ahead of gas at 28 per cent, nuclear at 11 per cent and imported power at around 10 per cent. Wind, solar and biomass all set records, and it was the first full year with no coal generation at all. On the surface, this is one of the cleaner big grids in the developed world.

The catch is how the price is set. In an electricity market, demand at any moment is met by stacking up power stations from cheapest to dearest, and the last one needed to meet demand sets the price paid to all of them. At peak times that marginal plant is almost always gas. So the wholesale gas price flows straight into the electricity price the same day, and a grid that is only a quarter gas-fired by volume is close to fully gas-priced at the moments that decide the bill.

This is why record wind and a Gulf oil war push power prices up together. The clean electrons are cheap, but they do not set the price; the marginal gas does. Decarbonising the grid has cut Britain's emissions sharply and its exposure to gas prices barely at all.

The firm capacity that could dull the effect is fading. Nuclear output fell to 36 terawatt hours in 2025, down 12 per cent and its lowest in half a century, as an ageing fleet paused for repairs. Nuclear is always-on power that does not track the weather or the gas price, so its decline pushes more load onto gas plants and imports just when both are expensive.

The cupboard Britain never built

A price spike hurts far less if a country can wait it out. Britain cannot, because it has almost nothing in store. It holds about 12 days of average gas cover, and closer to seven and a half at peak winter demand, against 89 days in Germany, 103 in France and 123 in the Netherlands. Most decision-makers assume the buffer is measured in weeks. It is measured in days.

That thin cushion is about to get thinner. The Rough facility off East Yorkshire accounts for roughly 70 per cent of Britain's gas holding capacity, and its owner Centrica has a production consent that expires in April 2027 with no current intention to seek an extension. Losing it without a replacement mechanism would leave the gas system exposed to any cold snap or supply interruption, with power generation the first to feel it.

Behind the storage gap sits a deeper trend: Britain increasingly imports its way to security. Domestic gas production fell in 2024 to its lowest since 1973, the mature North Sea is in structural decline, and import dependency for gas has climbed from roughly half to around 70 per cent since 2020. A country that once produced its own energy now buys most of it, which means its security depends on routes and chokepoints it does not control.

Note. This is the single number that most decision-makers get wrong. Britain does not hold days of gas cover the way its neighbours hold months.

Four refineries and a record deficit

The same import dependency has hollowed out the other half of the energy system, the part that makes the diesel and jet fuel no windmill can supply. Since the start of 2025 Britain has lost a third of its refineries, leaving four operating sites, the fewest in modern history. Grangemouth stopped processing crude in April 2025 and became an import terminal, removing about 13 per cent of national capacity on its own; the Lindsey plant collapsed into administration and shut by that October.

This matters because liquid fuels still supply 47 per cent of Britain's final energy, and there is no near-term substitute for the diesel that moves freight and the kerosene that flies aircraft (see the companion Insights analysis of energy risk in passenger air transport). With refining shrunk, the country now buys the difference: in 2025 it imported 15.5 million tonnes more petroleum products than it exported, the largest deficit since it became a net importer in 2013, and every tonne of that gap must arrive by ship.

The gas side has a matching single point of failure. Two of Britain's three main terminals for liquefied natural gas, gas chilled to liquid for shipping, sit in one Welsh estuary and feed the grid through a single trunk pipeline, yet together handle up to a quarter of national gas demand. A diversified-looking supply map hides several places where one fault would do national damage.

Where the price becomes permanent

For most households a high energy price is painful but temporary. For heavy industry it is often terminal, because these are continuous processes that cannot be switched on and off cheaply, so the rational response to sustained high costs is to mothball or close for good. The businesses at risk are a small but strategic cluster, steel, chemicals, fertilisers, glass, cement and ceramics, that make up more than 12 per cent of non-domestic electricity demand, contribute around £29bn to the economy and support over 210,000 direct jobs.

Their problem is a price gap that policy narrows but does not close. Even a British firm receiving state support pays around £86 per megawatt hour for electricity, against £69 in France and £60 in Germany. On that maths, output in chemicals manufacturing fell more than 27 per cent between 2019 and 2024. In April 2025 the government had to step in at British Steel's Scunthorpe works to stop the end of virgin steelmaking, the first time that capability would have been lost in Britain since the Industrial Revolution.

One closure shows how far the damage travels. When the fertiliser maker CF Industries idled its UK ammonia plants, it did not just raise fertiliser prices. Those plants are a major source of food-grade carbon dioxide, a by-product used to stun animals humanely before slaughter, to extend shelf life in packaging and to carbonate drinks. When the sites went dark in 2021, the government had to intervene for three weeks because the loss of that carbon dioxide disrupted pig and poultry slaughter, meat processing and food packaging. With domestic ammonia production now closing for good, that chokepoint has tightened, not eased.

The export logic is one-way. As ammonia, refining and virgin steel capacity closes, Britain replaces things it used to make with imports, moving jobs and resilience overseas. What leaves this way does not come back when prices fall, which is why an energy shock here leaves a permanent mark.

Note. Even after state support, a British factory pays more for power than a French or German one. That gap is what closes plants.

Who actually pays

The stress does not fall on the country evenly. It concentrates by fuel type, by geography and by how thin a household's finances are, and the sharpest case sits in Northern Ireland. Around 62 per cent of homes there, roughly 510,000 households, heat with oil rather than mains gas, against below 5 per cent in the rest of the United Kingdom. Heating oil is bought in bulk tank fills off a market that tracks crude directly and sits outside the price cap, so the 2026 oil surge hit these homes with no regulatory buffer at all, with reported increases of nearly 100 per cent in weeks on top of a fuel-poverty rate near a quarter.

Within Great Britain the same pattern holds in miniature: rural, off-grid homes on heating oil or bottled gas, and older, poorly insulated housing, carry the most exposure. On the official England measure under one in ten households is counted as fuel-poor, but a broader reading shows more than a third of UK households, close to nine million, already spend over a tenth of their after-housing income on energy. That is the population a further price rise lands on.

For anyone moving to Britain, the lesson is unusually concrete. Exposure is set less by income than by the building. A well-insulated, gas-connected urban home on a capped tariff is a completely different risk position from an off-grid rural property heated by oil, where the bill tracks global crude with no cap and no notice. Property selection is the single largest lever an incoming resident holds over their own energy costs.

The lights stay on. The bill does not.

Put the pieces together and the verdict is calmer than the headline numbers suggest, and more uncomfortable. Britain will keep the lights on and the pumps flowing this winter on any normal weather. The most likely path is not stability and not collapse but a prolonged, expensive grind: supply holds, prices stay punishing, and the margin of safety stays thin throughout.

The odds sit behind that judgement. A moderate-stress base case carries the largest single weight, but the three adverse scenarios together, severe disruption, systemic crisis and outright failure, add up to 38 per cent: roughly two-in-five odds that Britain sees at least meaningful industrial curtailment this winter, against a three-in-five chance the system holds at high but manageable cost. A genuine physical shortfall would need several bad things to stack at once, a cold, still spell, nuclear units offline, constrained imports and a supply interruption, on top of the thin storage.

Which is why the decisive variables are not geological but human. Britain's energy security in 2026 turns on two things outside the market's hands: how long the Strait of Hormuz stays contested, and whether the government keeps Rough open past April 2027. A clean grid is a real achievement. It is not, yet, a cheaper or a safer one, because gas still sets the price and the cupboard is nearly bare. The question for anyone with money, a business or a home exposed to Britain is not whether the power stays on. It is how much a thin margin is going to cost to hold, and for how long.

Note. The most likely winter is expensive, not catastrophic. But the three adverse paths together carry 38 per cent, roughly two-in-five odds of real industrial pain.

Figures drawn from TheRiskAgent's country energy risk report on the United Kingdom (September 2026): Ofgem, National Gas, DESNZ and House of Commons Library material, Centrica and operator disclosures, EU and IEA outlooks, and specialist energy trade reporting. Produced with AI research tools and reviewed before release. Reference material, not advice. The full analysis is at theriskagent.com.