What if Britain had built nuclear like France?

In this Britain, the grid runs on uranium, not gas.

Every winter the same argument arrives: French households pay less for power, French factories pay far less, and France sat out the worst of the 2022 energy crisis almost untouched. All true. This file exists to finish the sentence nobody finishes: they pay less because of a choice, and Britain made the opposite one, on purpose, and can watch the meter to prove it.

So we ran the counterfactual. Same houses, same weather, same demand. One change: Britain has the electricity system France actually built, roughly two thirds nuclear, ordered in the 1970s and long since paid off, instead of the gas-fired grid it chose in the 1990s. This is not a lobbying document for new reactors. It is the invoice for the ones we never built.

One number explains every bill that follows: how much of a country's electricity comes from nuclear. France sits at the top of the developed world. Britain sits near the bottom, in the company of the countries that quit. The fork in the road, drawn to scale:

Read that chart alongside your electricity bill, because they are the same story. Britain is not near the bottom because it was late or outclassed. It got there first. On 17 October 1956 the Queen flicked the switch at Calder Hall, the world's first grid-scale nuclear power station, and Britain did not stop there. By 1965 it had built more nuclear power stations than the United States, the Soviet Union and France combined. Twenty-six reactors went up between 1956 and 1971, most of them connected to the grid in four or five years. Britain did not join the nuclear age. Britain opened it.

Then it set the lead down and wandered off. The next-generation programme got bogged down, cheap North Sea gas came ashore, the electricity industry was privatised, and in 1995 the government flatly declared there was "no case" for it to fund new reactors. That same year Sizewell B was finished, and it remains the last reactor Britain has completed, thirty-one years ago. The fleet meant to follow it was scrapped, and of the reactors Britain did build, it has since switched off more than thirty. The nation that opened the nuclear age spent the 1990s dashing for cheap gas instead, in what got called the Dash for Gas, and called it prudence.

France did the exact opposite, and did it on purpose. After the 1973 oil shock, prime minister Pierre Messmer went on television in 1974 and bet the country on an all-nuclear grid: no oil, no drama, just uranium. EDF ordered sixteen reactors in that one year and built fifty-six in fifteen, roughly four a year at the peak, from two or three standardised designs so every reactor was a photocopy of the last. France took the standardised-reactor idea Britain had helped prove, and industrialised it while Britain lost interest. Britain invented the technology. France kept the receipts.

This is how a decision from the 1990s reaches your monthly direct debit. Britain prices electricity by the most expensive plant running: in every half hour, whichever generator is last through the door to meet demand sets the price for all the power sold in that half hour. In Britain, that last generator is almost always a gas turbine. So even the electricity that came from a wind farm or a reactor gets sold at the price of gas. Analysis of the market found gas set the British wholesale price about 98% of the time. In nuclear-heavy France, gas sets it roughly 7% of the time. When the world price of gas lurches, the entire British bill lurches with it. The French one shrugs.

This is the biggest reason Britain has the most expensive electricity in the developed world. On the IEA's cross-country league table, British households pay the highest domestic price of any member country, and British industry pays the highest industrial price of the lot, roughly two and a half times what a French factory pays. Gas is the heavyweight here: more than half of the entire increase since 2021, and strip out every levy and Britain would still have some of the dearest power in the rich world, because it wired its economy to the one fuel it had decided to stop producing. But there is a second reason the bill is so high, and it is the one Britain could actually fix by Christmas.

Having decided that electricity is the clean future, Britain then chose to load almost the entire cost of that future onto the electricity bill, and to leave gas very nearly alone. The green and social levies, the Renewables Obligation, Contracts for Difference, the old Feed-in Tariffs, the Capacity Market, the Warm Home Discount, add up to around 17% of a typical electricity bill but only about 7% of a gas bill, and both tick up again in 2026. Then add carbon pricing, which Britain charges on the gas burned in a power station but not on the gas burned in your boiler. Put it together and the pattern is perverse but deliberate: the cleaner the energy, the heavier the tax it carries.

To be fair about it, this is not wasted money. Those levies paid for the wind farms, and some of them fund real help for households in fuel poverty. The argument is not whether to spend it, it is where to put it, and Britain has put it in the worst possible place. The result is that British electricity costs roughly three and a half times as much as gas, unit for unit (about 26p against 7p), one of the widest gaps in Europe. That single ratio is why a heat pump, three to four times more efficient than a gas boiler, so often still loses on the monthly bill. Nesta reckons narrowing the ratio to about two and a half to one would take roughly £110 a year off a heat pump's running costs without changing a single piece of hardware.

So one arm of government spends its days urging you onto a heat pump and an electric car, while another keeps the electricity they run on deliberately expensive by parking the nation's entire green bill on it. It is policy fighting itself, in public, at your expense. But this own-goal, unlike the reactors nobody built in 1975, is not a fifty-year mistake. It is a line in the next Budget. Shift the levies off electricity and onto gas or general taxation, as the Climate Change Committee and a queue of others keep urging, and the gap starts to close the very next quarter. It would not undo the gas-set wholesale price, only a fleet of reactors does that, but it would at least stop Britain taxing the exact thing it keeps telling everyone to buy.

No vibes. Here is exactly what we did, and what we deliberately did not do.

What a British household would pay for the same electricity under the French system, next to what it pays now. Three homes: a flat, a typical house, and a larger household with a heat pump or an electric car.

Notice which way the gap runs as you electrify. The heat pump and the electric car, the two things Britain is officially urging every household to buy, are exactly the purchases that make the British price of electricity hurt most and the French price help most. Britain is asking people to plug more of their lives into the dearest electricity in the rich world.

All in, at typical consumption, a British household pays about 34p for every unit of electricity once the standing charge is counted, against about 22p under the French system. That is the whole argument in two numbers.

That last row is the control experiment. Germany spent the 2010s ripping out perfectly good reactors to loud applause, and now has some of the dearest household electricity in Europe, more per unit than Britain and roughly double France. So "be more European" is not the lesson, because Germany is European and Germany is a warning. Being more French is the lesson. The countries with cheap, clean, steady power are the ones that kept building reactors. The ones that switched them off are still paying the invoice, every single month, with interest.

And eight and a half billion is only the household layer, the bit you can see. It leaves out the factory that closed because its power cost more than its rival's in Lyon, the fertiliser plant that shut, the smelter that went cold and never lit again. British industrial electricity is the most expensive in the developed world, and that price tag is deciding which things Britain still makes. This is not a bill you pay once. It is a tax on everything, forever, for a decision taken before most of the country was born.

This is where nuclear articles usually turn into a fan club, so we won't. Three things are true at the same time, and a file that only tells you one of them is selling something.

First, the upside is bigger than the bill. A French-sized fleet would do more than cut bills. France's grid emits around 20 grams of CO₂ per unit of electricity; Britain's emits about 124, roughly six times more. France decarbonised its power sector some thirty years before Britain started trying, and did it without a single "net zero" slogan. France is a net exporter of electricity, about 89 terawatt-hours in 2024, some of it flowing down the interconnector into Britain. And when gas prices exploded in 2022, the British price cap leapt to £3,549 and the Treasury had to step in with a £2,500 guarantee, while France simply capped regulated increases at 4% that year. Firm, low-carbon power that does not flinch when gas spikes is the product Britain keeps saying it wants.

Second, building it new today is expensive. Hinkley Point C, the one station Britain is actually building, has climbed from around £18bn to roughly £46bn and slipped to 2029 or later, on a guaranteed price of £92.50/MWh in 2012 money, worth about £133/MWh today. New offshore wind was contracted at closer to £82/MWh. Built now, a unit of nuclear electricity costs roughly three times a unit of wind or solar. If the question is "what should Britain build next," honest analysts do not answer "only nuclear."

Third, and this is the important one, the cost is a choice about how you build, not a law of the atom. France's cheap power came from a fleet built fast and standardised in the 1970s. When France forgot that discipline and built a single bespoke reactor, its new Flamanville plant landed at roughly €23.7bn and twelve years late, and EDF now carries about €54bn of debt keeping the old fleet going. Britain's one-off at Hinkley has gone the same way. But the discipline still works for whoever keeps it. South Korea's engineers built the Barakah plant in the UAE, four reactors and 5.6 gigawatts for around $20bn, off one repeated design and a settled supply chain of Korean firms, and build at home on a roughly four-year construction clock at a fraction of the Western price. Britain is spending about £46bn for 3.2 gigawatts at Hinkley; Korea delivered nearly twice the power for less than half the money. The atom is not the problem. Building one of everything, once, having forgotten how, is the problem.

Put those together and the counterfactual is precise, not romantic. The cheap electricity in this file belongs to a Britain that built a standardised fleet decades ago and kept it, the way France did and the way South Korea still does. It was the road not taken in the 1990s. Britain could start walking it again tomorrow, with a committed, Korean-style programme rather than another heroic one-off, but the cheap bills would arrive in the 2040s, not at the next spending review. The choice is whether to pay once and coast, or keep renting your electricity from the price of gas forever.

Britain did not fail to invent nuclear power. It invented it first, and then lost its nerve. What France had that Britain did not was the stomach to keep building when gas looked cheaper, and the willingness to let the state, not the market, decide that some things are worth owning for fifty years even if they look mad for the first ten. France made an unfashionable, expensive, centrally planned bet in 1974 and has been banking the dividend every winter since. Britain took the cheap, flexible, clever-in-the-meeting option, and has been hostage to the price of gas, and the politics of whoever sells it, ever since.

The bill for that choice is not filed away in a think-tank annex. It is on the fridge, under a magnet, arriving every quarter: the highest household electricity price of any major economy, stapled to a grid that still asks a gas turbine what tonight's power should cost. And every heat pump and electric car the government now begs you to buy plugs you a little further into it.

• Ofgem, energy price cap 1 July–30 September 2026: electricity unit rate 26.11p/kWh, standing charge 57.19p/day. UK typical domestic electricity consumption ≈ 2,700 kWh/yr (Ofgem TDCV).
• EDF Tarif Bleu / Selectra, France electricity tariffs 2026: regulated base tariff €0.194/kWh, subscription ≈ €187.80/yr, following the 15% regulated cut of February 2025. Converted at €1 = £0.853 (July 2026).
• World Nuclear Association, Nuclear Power in the World Today: nuclear share of electricity by country (France 68.1%, UK 10.7%, and the full chart set), 2024 data. Fleet and country detail in the France and United Kingdom profiles (France ~57 reactors, ~61–63 GW; UK 5 operating stations, ~6 GW; Sizewell B, 1995, the last built).
• RTE, France Annual Electricity Review 2024: nuclear 67.1% of generation, 95% low-carbon, ~89 TWh net exports. Carbon intensity ~20 gCO₂/kWh in the 2025 review.
• Carbon Brief, why expensive gas is keeping UK electricity prices high: gas set the GB wholesale price ~98% of the time vs ~7% in France; wholesale ≈ 38% of a typical bill; ~53% of the post-2021 bill rise was gas-driven vs ~6% green levies.
• Carbon Brief, UK electricity was cleanest ever in 2024: UK mix (gas 28%, wind 26%, nuclear 13%) and grid carbon intensity 124 gCO₂/kWh (2024).
• Nesta, policy costs in energy bills: environmental and social levies are around 17% of a typical electricity bill versus about 7% of a gas bill (rising to 18% and 8% from January 2026). The resulting electricity-to-gas price ratio of roughly three-and-a-half to one is a leading reason heat pumps struggle to beat gas on running cost; a ratio nearer 2.5 to 1 would save about £110 a year. Rebalancing levies off electricity is urged by Nesta, the Climate Change Committee and Green Alliance.
• IEA cross-country electricity prices (via IEA think-tank analysis) and DESNZ Quarterly Energy Prices (June 2025): UK domestic and industrial electricity the most expensive of any IEA country; UK industry roughly 2.5× French rates.
• House of Commons Library, gas and electricity prices during the energy crisis: Ofgem cap peaked at £3,549 (Oct 2022); the Energy Price Guarantee capped a typical bill at £2,500. France's regulated increases were capped at +4% (2022) and +15% (2023) per Connexion France.
• NucNet / EDF on Hinkley Point C: cost risen from ~£18bn toward ~£46bn (nominal), delayed to 2029–2031; strike price £92.50/MWh in 2012 prices. Offshore wind CfD Allocation Round 6 (2024) ≈ £82/MWh in 2024 money; Lazard LCOE+ (June 2024) puts new nuclear at roughly three times the cost of wind or solar.
• Cour des Comptes on Flamanville 3: total cost recalculated at €23.7bn including financing, ~12 years late, connected December 2024. EDF net debt €54.3bn at end-2024 (EDF 2024 results).
• World Nuclear Association, nuclear power in the UAE (Barakah): four APR-1400 reactors, 5.6 GWe, built by a KEPCO/KHNP-led Korean consortium (with Samsung, Hyundai, Doosan) for about $20.4bn including commissioning and fuel; units connected to the grid 2020–2024. Korea's standardised APR-1400 build (WNA, South Korea) runs on a roughly four-year construction period at an order of magnitude closer to $3,000/kW, against Hinkley's roughly £46bn for 3.26 GW.
• Works in Progress, on the Messmer Plan: France ordered 16 reactors in 1974, built 56 in ~15 years at roughly four a year, using standardised designs and ~6-year build times.
• Works in Progress, how Britain learned and unlearned nuclear: Calder Hall (17 October 1956) was the world's first grid-scale nuclear station; by 1965 Britain had built more nuclear stations than the US, USSR and France combined; 26 reactors built 1956–1971; Sizewell B (1995) the last completed, after the 1995 "no case" decision. The UK has since shut more than 30 reactors (World Nuclear Association).
• Full model: identical annual consumption run through both default tariffs, standing charges included; UK from the Ofgem cap, France from the EDF regulated tariff; €1 = £0.853. The whole retail gap is attributed to "the French system," a conservative choice that does not isolate the nuclear-only effect. Household aggregate uses ~28 million GB households.