The October gas price at the Dutch TTF hub, a g benchmark, was seen to climb to a record high of 79 euros ($93.31) a megawatt-hour on Wednesday. The contract has risen more than 250% since January, according to Reuters, while benchmark power contracts in France and Germany have both doubled.

In the U.K., where electricity bills are now the most expensive in Europe, power prices have soared amid the country’s high dependence on gas and renewables to generate electricity.

British day-ahead electricity prices rose nearly 19% to reach 475 pounds ($656.5) on Wednesday, Reuters reported. The contract was already trading near record highs shortly after a fire at a U.K.-France power link cut electricity imports to Britain.

“By far the biggest factor is gas prices,” Glenn Rickson, head of European power analysis at S&P Global Platts Analytics, told CNBC via email.

Higher gas prices have also been a “big driver” in lifting carbon and coal prices to record highs too, Rickson said, although he noted there are other supporting factors at play, such as low wind generation and nuclear plant unavailability across the continent.

Carbon prices in Europe have nearly trebled this year as the European Union reduces the supply of emissions credits. The EU’s benchmark carbon price climbed above 60 euros per metric ton for the first time ever in recent weeks, trading slightly below this threshold on Thursday.

The EU’s Emissions Trading System is the world’s largest carbon trading program, covering around 40% of the bloc’s greenhouse gas emissions and charging emitters for every metric ton of carbon dioxide they emit. Record carbon prices have made highly polluting sources of energy generation even less attractive because coal, for example, emits more carbon dioxide when burnt.

Rickson said the outlook for European power prices this winter will be “highly dependent” on gas prices, adding that he expects gas prices to rise even further in the coming months. “Aside from the ‘average’ picture, we expect prices to be highly volatile, with swings from low or even negative hourly prices when wind generation is high, to very high prices as already seen when wind is low, and demand is high.”

How did we get here?
European gas prices have accelerated since the start of April, when unseasonably cold weather conditions meant Europe’s gas in storage dipped below the pre-pandemic five-year average, indicating a potential supply crunch.

Europe has since struggled to bring gas supplies that are necessary for the winter period back to where they should be. An economic rebound as countries eased Covid-19 restrictions also coincided with higher-than-expected demand that led to a shortage of gas.