One example: my energy provider builds biogas plants. Guess what, they turn agricultural waste into electricity. Even at night.
Your argumentation is similar to suggesting Tesla should stop developing electrical cars because there is no charger infrastructure. So 2010.
I thought biomass was marginal but you actually produce almost as much electricity with biomass as with natural gas. I stand corrected. https://en.wikipedia.org/wiki/Electricity_sector_in_Germany
How can you receive energy purely from renewable energy sources when the wind doesn't blow and the sun doesn't shine? Germany doesn't have any significant capacity for electricity storage. It's such a bold statement but it seems physically impossible.