The European electricity market is working quite well, imports and exports are expected to happen. Countries prefer to import electricity when it is cheaper than producing it themselves. Germany has more than enough capacity installed to handle its energy needs (even if a lot of this is still fossil). Germany does not have an "often unstable electricity grid", not at all. That information is simply wrong.
In other words, shutting down nuclear plants means a) replacing the energy generation with coal (mostly lignite), or b) importing energy from other countries, which generate it from coal (mostly lignite) like Poland.
Importing will likely be "cheap", because we all agree to collectively pretend that externalities like CO2 emissions or catastrophic pollution from coal plants are not a thing.
Oh no no. Germany loves importing nuclear electricity from France, Czech Republic and others too. Makes the government feel good about having quit nuclear, because somehow when it comes from across the border it's not so bad anymore.
Many of your comments are misleading and are often renewable energy propaganda.
"In 2023, Germany lacks 15 to 20 gigawatt of secured power output”. This comment was from Harald Schwarz, Professor for energy distribution and high voltage technology at the Brandenburg University of Technology. EU Fact check rates this as mostly true.
The claim that germany has sufficient capacity for its energy needs is just wrong.
That is true, but it is also not the goal to achieve 100% secured power output, nor is it necessary. The calculations that determine the necessary electricity production to cover Germany's needs at all times are more complicated than just looking at the installed secured power output and involve factors, such as the likelihood of unavailable renewable energy production. And even if the worst case happens, there are solid strategies in place to avoid a blackout, including backup power plants and coordination with high energy consumers to reduce or shut down their consumption.
And all of this still ignores the fact, that there is a highly connected international electricity market, that large scale storage solutions are being prepared, and that the grid is becoming more decentralized.
this is all well and good but seems to ignore the central problem - energy security is a national priority. Hand waving away the problem by pointing to energy markets or a decentralised grid does not address the fundamental issue.
You are right, the goal is not 100% secured energy supply but we have multiple problems at the same time - energy security and climate change to name just two.