The heads of the three major French energy companies are calling on private individuals and companies to save electricity immediately.

"We must work together to reduce our consumption in order to regain room for manoeuvre," wrote the bosses of Engie, EDF and Total in an open letter published by the weekly "Journal du Dimanche" on Sunday.

In their letter, Catherine MacGregor (Engie), Jean-Bernard Levy (EDF) and Patrick Pouyanne (TotalEnergies) cite the sharp drop in Russian gas supplies and limited power generation due to maintenance problems as the reasons for this.

"If we take action this summer, we can be better prepared by the start of next winter, particularly to preserve our gas reserves,"

according to the top managers of the energy companies in their letter.

They added that efforts to limit consumption should be "immediate, collective and massive."

France wants to fill its gas storage facilities by early autumn, as Prime Minister Elisabeth Borne said recently.

The country's gas storage facilities are currently around 59 percent full.

The situation in Germany and other countries is similar.

Executives cited their own efforts to develop new gas wells and build a floating liquefied natural gas (LNG) terminal in the Port of Le Havre.

According to media reports, the government has held talks with TotalEnergies about increasing LNG capacity after the US announced its willingness to increase shipments to Europe.

France recently extended its gas price regulation mechanism until the end of the year.

The scheme, originally due to run until the end of June, aims to limit the impact of rising energy prices on consumers' purchasing power.

Meanwhile, France is preparing for the restart of the coal-fired power plant in Saint-Avold near Saarbr├╝cken.

The power plant, which only went offline at the end of March, should be put back into operation next winter as a precautionary measure in view of the tensions on the energy market and the situation in Ukraine, the Ministry of Energy in Paris announced on Sunday, as reported by the broadcaster BFMTV.

That doesn't change anything about the fundamental decision to phase out coal.

Except for a reserve power plant, the plant in Lorraine near Saint-Avold was the last in France.

The basis for restarting the power plant is a law to cushion the crisis, which is to be passed in July, the broadcaster RTL reported.

The 71 employees who were laid off at the end of March could therefore be reinstated at short notice and for a limited period until the end of 2023.

In the weeks before its closure, the power plant had been burning coal at full speed to meet its electricity needs.

Russian natural gas does not play a major role for France.

Around half of the nuclear power plants are currently off the grid due to defects or maintenance, so that the reactors deliver less electricity than usual.