Last year the EU produced 42% of its electricity with renewables. 18.9% of it with wind and 8.0% with solar. There is also a 24.5% share of nuclear, which is probably going to stay stable. That leaves 31.9% fossil fuels. So we have to a bit more then double wind and solar installations in the EU. That is entirly possible to do. Especially with offshore becoming as cheap as it is and we still have a lot of rooftops without solar.
About storage there is a wonderfull thing called electricity grids. The worst days for wind last year wind made up a bit less then 10% of electricity production. That is of an average of 18.9% over the entire year. For solar it is worse in wind, but luckily wind makes up a lot of the rest. Combined that means that the worst days still have 13% wind + solar EU wide. So about half of average. As soon as you extend it to a week the worst ones are at something like 17% of wind + solar. So with a strong enough grid we get pretty close. As soon as you add a bit of storage to the grid and overbuilt wind and solar a bit, renewables work just fine.
Honestly we are pretty close to solving it. Most EU countries are at over 50% clean electricity today. Even better Putin caused massive built ups of clean power generation. We are going to be fine, if we continue in that field.
They are restoring rule of law in Poland. So it depends, if you like PiS or not.