Investing enough into renewables combined with grid scale storage to cover a prolonged Dunkelflaute is very expensive, therefor German government is investing in new gas-fired power plants with capacity of 11 GW, with state subsidies.
And this is exactly why Germany is not serious about its obligations to fight Global Warming. Always choosing the easy or demagogic way out, whether it was running on cheap Russian gas, or mothballing nuclear and restarting lignite coal power plants.