The growing emphasis on ESG is a key component in the upstream oil and gas industry.

Germany, which has the European Union’s biggest economy, and other countries intend restarting mothballed coal-fired power plants and extending the life of their nuclear power plants to reduce their reliance on Russian gas and coal following its invasion of Ukraine.

The EU’s energy agency, Acer, has warned against tearing up the market structure. In a report in April, it said that the EU’s wholesale electricity markets work well under normal conditions, ensuring secure electricity supply.

Asked if there are guarantees that Gazprom will restart gas flows via Nord Stream 1, the Kremlin's Peskov said: "There are guarantees that, apart from technological problems caused by sanctions, nothing hinders the supplies."

A three-day halt of the Nord Stream pipeline -- a key source of natural gas for the European Union -- starts on Wednesday, and concerns are widespread that Moscow will find another excuse to clamp down on supplies, putting the region at the mercy of the weather.

European natural gas prices on Monday plunged the most since March after Germany said its gas stores are filling up faster than planned.

Europe’s benchmark electricity price has risen to 10 times its decade-long average, in line with a 14-fold increase in the cost of gas, amid fears of shortages this winter.

With Russia squeezing gas deliveries and power-plant outages further sapping supply, pressure is growing on EU leaders to act quickly or risk social unrest and political upheaval.

Bern has been working to build up Switzerland's energy production and storage systems, but even the grand opening next month of a new, powerful pumped-storage hydroelectric plant is unlikely to help avoid problems this winter.

Benchmark Dutch front-month futures fell as much as 16%, partly reversing last week’s jump of almost 40%.