At Nyrstar, the only zinc manufacturer in France, in Auby (Nord), production is now managed on a weekly basis, depending on variations in the cost of electricity, the soaring threat of which is to put the machines on the line. ‘stop.
For the time being, under the large hall, in pools 60 meters long filled with liquid zinc sulphate and crossed by electric current, the ballet of cathodes continues day and night. In 40 hours, these large plates will emerge from the electrolysis covered with the zinc thus obtained.
Plant manager Xavier Constant knows production will continue until January 16. But “for the following week, we have no visibility. We reason from one week to the next”.
If the price of electricity soars again, the large hall will be shut down. Because with its 82 megawatts, the Auby plant represents 10% of the power of a nuclear power plant, and consumes as much as a city like Lyon or the Metropolis of Lille.
Behind the plant, amid the hum of transformers, two very high voltage lines directly supply the site with 225,000 volts.
– “Never known levels” –
“For a zinc atom, you need two electrons. It’s chemistry, it’s immutable”, sums up Xavier Constant. To produce 170,000 tonnes of zinc annually, the plant consumes 730 GWh.
“In recent times, prices have soared to levels that I have never known in my career”, testifies Eric Brassart, CEO of Nyrstar France.
From 40 euros a few years ago, the average price of MWh over a day exceeded 400 euros before Christmas, with hourly peaks of more than 600 euros.
Nyrstar then decides to stop production for two months, from the beginning of January. “The more expensive electricity will be, the more it will impact your costs, until you lose the break-even point,” explains Eric Brassart.
But “between Christmas and the New Year, the weather was mild, with wind and a lot of wind production in France and Germany,” adds Xavier Constant. Prices have calmed down. They are currently flirting with the 230 euros.
“We did not hesitate for a second, we bought blocks to run the plant for a week. This week, we renewed the operation for next week,” explains the director of the plant.
– “400 factories impacted” –
“This is the first time that we have had to make this decision since the creation of our electrolysis in 1975. It is an exceptional situation”, he underlines. For the moment, “we lose less money by continuing to produce than by stopping. But we lose some all the same”.
“If we lose money in the long term, the activity will not be able to continue”, worries Eric Brassart. “But this is not a problem specific to Nyrstar. It is the 400 electro-intensive factories which are impacted in France”.
Which fear a lasting disadvantage, in the face of international competition. “Finland, Norway, Canada, Brazil: all these people pay between 30 and 50 euros per MWh for electric current” to produce their zinc, notes Xavier Constant.
He deplores the overheating of an energy market that has become European, noting “the surge in gas prices, on which the price of electricity is indexed”, “the historic low availability of French nuclear reactors” this winter forcing the countries to be imported, or an Arenh mechanism (for “regulated access to historic nuclear electricity”) which supplies MWh to manufacturers at a fixed price of 42 euros, but whose availability has been reduced “to heartache”.
If production had to stop, the employment of the 300 site employees would be maintained on maintenance activities, training or reassignments to other site facilities. But according to Nyrstar, France would then have to import Indian or Chinese zinc, “with a much larger carbon footprint”.