LONDON — When Jakob Bitner was 7, he left Russia for Germany with his parents and sister. Twenty-eight years later, he is set on solving a vexing green-energy problem that could help Germany end its dependency on imported energy from Russia, or anywhere.The problem: how to make wind and solar energy available 24 hours a day, seven days a week, even if the sun is not shining or the wind not blowing.The company he co-founded in Munich in 2016, VoltStorage, found some success selling storage battery packs for solar power to homeowners in Europe. Now the company is developing much larger batteries — each about the size of a shipping container — based on a chemical process that can store and discharge electricity over days, not just hours like today’s most popular battery technology.These ambitions to overcome the u …
