alt Hacker NewsThat's right, Germany sells electricity to other countries during the day and buys electricity in the evening because there is no sun then.
The problem is that other countries also have solar and wind power during the day and don't need this electricity at all. That's why Germany has to “sell” this surplus electricity, even though no one needs it. To ensure that the electricity is still "purchased", Germany has to pay money for it. In the evening, Germany has to pay money to buy back the missing electricity.
Paying money to have something purchased is generally referred to as garbage fees.
That does not seem to be a long term problem. Wind and solar can be down regulated with ease (and within fractions of a second), a negative prices only happen because producers got a flat-fee per kWh which is pretty much phase-out now. The problem is rather that Germany (plus Luxembourg) is still a single price zone, i.e when wind is blowing in Hamburg, the per-kWh price in Passau is also nill. While this is nice for Bavaria (the main culprit, as usual), there is an enormous cost for this in the form of re-dispatch fees as long as the grid is not strengthened a lot.