Extensive research is conducted on the improvement of renewable energies. One field is the use of wind energy, where the tower construction is one of the main issues. This paper deals with new ideas and ongoing research in this area. To raise the height of steel tubular towers, fatigue as the design limit and constraints due to transportation issues have to be overcome. Changes in the cross-section are considered as one of possible solutions. This work presents an extensive finite element study dealing with different ways to improve shell stability, which become the limiting criteria if a friction connection substitutes the common flange connection between two tower segments. The use of circular and polygonal cross-sections is briefly described and will be investigated in an experimental program.