Europe’s blistering heatwave is heaping further strain on the continent’s energy system, putting upward pressure on power prices and heightening the risk of serious gas supply shortfalls this winter.

Record-breaking temperatures this summer have pushed up energy demand for cooling and hit electricity generation from nuclear, hydro and coal sources at a time when Europe is seeking to cut its reliance on Russian gas.

“The hope was that summer would provide some release for the European energy market,” said Fabian Ronningen, analyst at Rystad, a consultancy. “But this heatwave will add to the crisis further down the line and it looks bad for winter. It’s close to our worst-case scenario.”