80% of their power is generated by nuclear. Of their nuclear plants, way over half the fleet has been offline for months because of inspections and sometimes substantial damages from age-related corrosion issues [1], and the other half is severely limited or cut off as well because the rivers that they depend on for cooling can't keep up [2]. And since the entire continent is a single synced grid, someone has to cover the gap, and that's German gas peakers [3].
Unfortunately, European energy markets operate at the "merit order" principle [4] which means that the highest bidder on the spot market sets the price for everyone else - which means while gas peaker plants generate extremely expensive energy for France, the operators of any other type of plant get the exact same high price leading to billions of euros in excess profit for them [5].
France also has another problem, and that's the EPR design that has led to severe budget and time overruns. Not just generic issues, but massive design defects [6]. They bet on Flamanville replacing a bunch of the aged plants, the bet failed, and no one knows when that reactor will finally come online. Flamanville was projected to cost 3.3 billion euros and be ready in 2012 - current estimates are at 12.7 billion euros at the least and a start in Q2/23 [7], and other EPR projects are just as bad.
[1] https://www.france24.com/en/france/20220825-france-prolongs-...
[2] https://www.theguardian.com/business/2022/aug/03/edf-to-redu...
[3] https://www.swr.de/swraktuell/baden-wuerttemberg/suedbaden/w...
[4] https://www.focus.de/finanzen/boerse/merit-order-wie-ein-gut...
[5] https://www.derstandard.de/story/2000137852348/gas-und-oelpr...
[6] https://www.express.co.uk/news/science/1645421/energy-crisis...
[7] https://www.reuters.com/business/energy/edf-hopeful-end-sigh...