Apparently because of a software problem, the municipal utility in Strasbourg, France, accidentally sold too much electricity, causing a loss of 60 million euros.
It cannot be ruled out that human error was the cause of the unplanned sale of electricity, said a spokesman for Electricité de Strasbourg, a subsidiary of the energy company EDF, on Monday.
The company had twice sold larger amounts of electricity in the past week, first two gigawatts, then 5.75 gigawatts.
However, since it did not have these quantities, Electricité de Strasbourg had to buy back the electricity at a higher price.
The estimated damage of 60 million euros is just under the company's annual profit from last year.
Grid operator RTE said it had informed neighboring countries to import electricity in an emergency.
However, this did not become necessary.
According to the company, the incident had no impact on the approximately 560,000 customers of Electricité de Strasbourg.