Hungarian Power Hits 18-Month High as Paks Nuclear Cooling Curbs Bite in Heatwave
Heat-driven cooling restrictions stripped 0.5 GW from the 2 GW Paks plant, sending Hungarian day-ahead prices 31% higher to EUR 290.71/MWh.
Hungarian day-ahead power prices jumped 31% on Monday (2026-06-29) to an 18-month high of EUR 290.71/MWh as heat-driven cooling restrictions cut output at Hungary's 2 GW Paks nuclear power plant by 0.5 GW, Montel reported. A heatwave tightened regional supply across Central Europe, leaving Hungary's residual generation and import capacity to set a sharply elevated clearing price.5,4
Paks supplies a substantial share of Hungary's electricity and has limited flexibility when ambient temperatures reduce its cooling capacity. A 0.5 GW output restriction from a 2 GW plant removes a quarter of installed capacity precisely when summer heat-driven demand is highest, leaving a country with limited large-scale dispatchable alternatives to absorb the gap through imports or gas generation at prices the market was willing to pay. Analysts at Montel noted the tightening in supply rippled beyond Hungary's own borders into the regional power balance.4,5
European power markets have shown recurring vulnerability to supply tightness this year as low wind speeds and constrained generation have combined to compress available margins, according to OilPrice.com reporting based on Bloomberg data. The Paks curtailment follows the same pattern: a sudden reduction in available supply during peak demand conditions forces a sharp spot repricing.2
Gas prices were not the mechanism behind the Hungarian spike. ICE Endex TTF front-month was at EUR 42.75 per megawatt-hour — enough to support gas-fired generation but far below the level that would mechanically push day-ahead power to EUR 291. The driver was physical nuclear availability, not fuel cost.5
Not all southeastern European markets faced equivalent pressure. Improved hydropower availability across the broader region, combined with regional power producers having bought gas positions in advance, shielded some countries from the sharpest spot price moves, analysts at Montel said.1 Hydropower-endowed markets entered the heatwave with a dispatchable buffer that Hungary, reliant on Paks as its dominant non-thermal source, could not access.1
European power prices more broadly spiralled to multi-year highs at various points this year on a combination of carbon costs, commodity prices, and low wind output, CNBC reported. The Paks curtailment adds a nuclear supply dimension to that mix — one that is harder to hedge in advance than weather-driven generation swings.3
The episode poses a positioning question. Summer nuclear curtailment risk at Paks is structurally predictable: it depends on temperatures and river conditions that become clearer in the days before settlement. A 31% single-session jump to an 18-month high on a known curtailment scenario suggests forward hedging against this specific risk was insufficient, at least at day-ahead settlement. Whether that reflects a pricing failure or a deliberate bet on temperatures normalising quickly is a question markets will revisit if heatwave conditions persist through the week of June 30.5,4
The near-term signal is Paks output status and temperature forecasts for the days ahead, which will determine whether Monday's (2026-06-29) EUR 291 print represents a one-session spike or the start of a sustained spot premium. If cooling restrictions ease, the differential to regional benchmarks should narrow rapidly. If they persist, traders with Hungarian power exposure face another session at the higher clearing level.5