What I'm saying is that since production costs are stable, as long as they set a price that covers actual costs then this price control does not actually cost them money, only potential profits, so it is sustainable.

It leads to shortages instead as people find ways to arbitrage the price - buy French nuclear power cheap then export it for profit.

Fundamentally you can have high prices, shortages or you can disconnect France from the rest of the European grid but you cannot just have cheaper prices in France.

This is absurd in several levels - you can't move electricity in a box, there are only a few interconnects, all of them regulatable and controllable, they can only move like 15% of tital supply and prices are different for business and for home use.

And nothing you've said seems to have relevance to shortages

Yes exactly, your chosen option is to disconnect France from the shared grid (calling it "regulation" doesn't change anything).

There are already electricity price controls in France, which still also exports at market prices.

As ClumsyPiloy said electricity is not something you can easily trade under the radar of the regulator. Technical limitations and regulation do change everything.

At least with nationalisation it's not only the losses that are socialized, right?