Germany puts a special focus on the development of renewable energies. Wind power has the highest potential of generated electricity expansion of all renewable firms of energy. A special attention is given to land based turbines, in order to ensure the efficient economical operation of massive hubs raising 100 m over the ground. By increasing hub height, the complexity of transporting and assembling of the tower simultaneously expands. The optimization of the support structure and the new assembling concept is the aim of the new Hybrid²-Towers for onshore wind energy plants. The dead-weight of the concrete tower is decreased by 40 % compared to a traditional full concrete tower with this new design proposal. As a positive consequence, the cost for assembling will be reduced. The Hybrid²-Tower is currently developed at the Technische Hochschule Mittelhessen (University of Applied Sciences, Gießen Germany). It combines the possibilities of precast concrete elements and steel members and improves the performance of the whole tower structure. The Hybrid²-Towers are made of precast concrete corner elements. A steel framework connects the elements with each other. In this way, the dead-load of the tower elements is reduced significant and the assembling-time is shortened.