[Majromax]

If you're buying and selling the power, then you don't care much about the absolute price, but rather the delta between the purchase and sale prices.

Below -100€/MWh, you don't need to sell the power to profit; you'd make at least some money just using it to heat up a big resistor.

[thyristan]

You didn't read what I wrote. The news is about trading prices. End users never pay those, because there are fixed network fees to be paid on top. So the actual bill will practically never have a negative price on it anywhere.

And even if there were negative end prices happening: There are metal smelting works and other operators of big resistors who will happily heat up even more. So prices will probably never get so negative that a normal consumer can ever profit from them.