British Nuclear Costs Darken Europe's Power Supply Horizon as German Prices Climb

British Nuclear Costs Darken Europe's Power Supply Horizon as German Prices Climb A fourfold cost overrun on Europe's most recent nuclear build makes the continent's supply gap structural, as German Q2 power faces a forecast 17% year-on-year rise. The most recently completed nuclear reactor in Europe finished twelve years late. The project in France came online last December (2025) with costs that had risen from an initial estimate of £2.85 billion to over £11.4 billion, according to a report published on Saturday (2026-05-31) by Oilprice.com. A separate British government review in 2025 concluded the UK was the most expensive country in the world to build nuclear power plants.⁴ For European power traders trying to map medium-term supply, those numbers do real work. Germany's economy minister has been discussing a nuclear return openly, Montel reported in the week of 2026-05-21, as the EU confronts what analysts describe as a second energy price crisis in four years. The distance between political discussion and generating capacity is, on current evidence, measured in decades and multiples of budget.¹ German Q2 spot power prices are forecast to rise 17% year on year, analysts told Montel on Thursday (2026-05-21). Gas prices are driving the floor: Montel reported forecasts of EUR 46.35/MWh for Q2 gas, an increase of EUR 13.20 or 40% from Q2 2025 levels. At that level, gas-to-power economics stay under pressure for the full quarter.² Solar is the main offset. The same analysts noted that expanded photovoltaic output and slightly softer demand should limit spot power gains below what the gas market alone implies. German summer solar capacity has grown steadily over recent years, and its midday price drag is consistent enough now to feature in any serious Q2 forecast.² The UK's fourfold nuclear expansion target, announced by the government in 2024, does not change the near-term picture for European power. If the French cost trajectory applies to British projects — and there is no obvious reason it should not — first meaningful new capacity arrives well into the 2030s at prices well above current estimates. Regulatory simplification, as proponents argue, can shorten permitting queues. It does not change the physical complexity of pouring nuclear-grade concrete.⁴ The Middle East conflict is running as a background pressure on European gas import costs. The IMF warned that the conflict is feeding into higher prices and weaker growth, with the UK identified as among the most exposed European economies given its reliance on imported gas. That vulnerability carries knock-on implications for gas-linked power pricing on the continent.³ Italy is delaying its coal phase-out, Montel reported alongside the energy crisis analysis in the week of 2026-05-21, which provides short-term thermal capacity and softens some regional power tightness. It is a stopgap, not a strategy, and does nothing to resolve the structural supply question that the nuclear cost data now frames more sharply.¹ The signal to watch heading into June is whether the solar offset holds. German irradiance in June can vary significantly, and any run of cloudy weather removes the cushion that analysts are relying on to cap the 17% year-on-year surge. Without that photovoltaic buffer, the full weight of a 40% increase in gas prices flows into spot power without dilution. The nuclear debate, wherever it lands politically, is not a variable for this quarter. What lands in June is gas prices, solar output, and demand — and the first of those three is already pointing in one direction.^2,4