Steel tanks for biogas plants compete with concrete tanks and are subject to enormous cost pressure. We know that steel tanks remain an attractive alternative but we cannot waste a gram of material in the design. In the design, stability is the governing factor. Shell buckling is one of our favorite topics, as we also encounter it in our other fields of business. It is our strong academic background regarding this topic and a lot of experience coming from different problems to solve that allow us to tackle the challenges in the steel tank design with state-of-the-art analysis methods.