France, Spain Power Top EUR 100/MWh as 42C Heatwave Hits Western Europe

France, Spain Power Top EUR 100/MWh as 42C Heatwave Hits Western Europe An extreme heatwave has driven front-week French and Spanish power above EUR 100/MWh, with analysts warning the cooling-demand spike will persist into this week. An extreme heatwave of up to 42C across western Europe this weekend (2026-06-20/21) pushed front-week power prices above EUR 100/MWh in France and Spain, and analysts told Montel the strength will carry into the week of 2026-06-22.⁶ That matters for a market that has spent much of the year fighting the opposite problem. European power has repeatedly crashed through zero on renewable gluts, and the swing to triple-digit prices on cooling demand shows how quickly the summer story can flip. Spanish day-ahead power was indicated at around EUR 81/MWh in early trade on Monday (2026-06-22), so the front-week premium analysts described sits well above the prompt.⁶ The mechanism is air conditioning. A 42C reading is not a marginal warm spell; it is the kind of heat that forces cooling load to the top of the demand curve through the afternoon and evening, when solar output begins to fall away. Spain was expecting the brunt of it, according to the analysts who spoke to Montel.⁶ The fuel mix explains why the price reaction can be sharp. Solar supplied close to 39% of EU generation in June, the largest single source in the latest ENTSO-E monthly print, with wind onshore at roughly 9% and gas at about 8%.⁶ Solar is abundant at midday but absent at the evening peak, so when cooling demand runs late into the day, the marginal megawatt shifts to gas and the price follows it up. This is the structural feature that traders have watched build for a decade. Wind and solar now account for more than 40% of Spain's total electricity supply, and the wholesale price was 40% lower in 2024 than if the matrix had stayed as it was in 2019, according to a study by the Bank of Spain cited by The Economist.³ Cheap when the sun shines, exposed when it does not. The pricing power of that exposure is visible in the data. Gas plants set the Spanish power price in just 15% of hours so far in 2026, Ember calculates, against 89% of hours in another European market in the same period.⁴ A heatwave is precisely the setup that lifts that share, because evening cooling demand pulls thermal plant back to the margin. When gas sets the price, European power tracks TTF, which traded near EUR 42/MWh on Monday (2026-06-22). The interconnection question sits underneath all of this. Spanish Prime Minister Pedro Sanchez said on Tuesday (2026-05-19) that Spain cannot wait another decade for decisions on new power links with France, urging Brussels and Paris to speed up projects to help cut European bills.¹ The Iberian peninsula remains weakly connected to the rest of the continent, which limits how much cheap Spanish solar can flow north when France is short and how much French supply can flow south when Spain is squeezed by heat. Capacity is being added at pace. More than 70 GW of renewable capacity was added across Europe in 2025, led by Germany, Spain and France, according to a study by Montel's EnAppSys, EQ and Energy Brainpool.² But the same study found that rising renewable output has not consistently translated into lower emissions, a reminder that buildout and decarbonisation are not the same thing, and that thermal plant remains the swing supplier on days like this.² The grid carries its own risk. In April 2025 a sweeping outage left millions in Spain, Portugal and parts of France without electricity, a failure that fed into a connection between France and Spain.^7,5 A heatwave stresses both demand and the network at once, and the memory of that blackout is a reason traders pay attention when Iberian load spikes. For the week of 2026-06-22, the trade is in the shape of the day. Solar will cap midday prices and may push them toward zero again at the sunniest hours, while the evening peak does the opposite as cooling demand outlasts the sunlight. The wider the intraday spread, the more value sits in flexible gas, hydro and battery capacity.^6,3 The signal to watch is duration. A single 42C weekend is a spike; a fortnight of it is a fundamentals story that drags front-month contracts and pulls gas burn up with them. Whether the heat breaks or settles in over the coming days will decide which it is, and how hard the evening peak bites when Spanish solar clocks off.