Storage capacity has to be built along with solar and wind parks. Its already happening. But more investments are required ("more effective" than nuclear). And the electric grid must be decentralized further to accommodate decentralized storage (from your wall-box at home to industrial storage facilities). And it must not stop at borders.

Regenerative energy already surpassed all other means of energy production in 2024: https://www.bdew.de/media/documents/2024_12_18_Die_Energieve...

Battery prices are declining for some time now: https://www.bloomberg.com/news/articles/2024-12-10/electric-...

And even larger storage capabilities are built: https://standort-sachsen.de/de/aktuelles/news/detail/n1474-g...

(I am actually working for a grid operator)