The Windbrücke and multigenerator system for alpine sites

Abstract

Wind turbines with multirotor systems are a technical response to a rapid expansion of wind power in the Swiss Alps. Several structural and economic advantages of such turbines have been identified in the literature. Previous studies have shown a cost reduction of more than 25% for a multi-megawatt multirotor turbine compared to a single-rotor turbine with the same rated power. It is equally known from published scientifically supported measurements that an additional 2% extra yield can be achieved than a comparable single-rotor turbine with the same harvest area.

The idea shall be tested on a 1:10 full scale small tower (1:10 scale model of a 15MW full turbine size), with three nacelles and a maximum height of 35m (MR30).

This demonstration wind turbine will demonstrate the technical and commercial feasibility of this new multirotor wind turbine. With three individual machines rated each 30kW, the loads in the support structure are measured, the information is implemented in the control system and optimized in a load-saving way. This relieves the critical parts of the large structure and allows smaller and thus more economical dimension for the alps.

The entire wind turbine for the alps and the test can be erected on site without a large crane footprint. This possibility is achieved by limited component weight and new lifting techniques for both, structure, and nacelle. In addition, the total height of the test turbine of 35m can fill a possible product gap for small wind turbines in Switzerland. The appearance of the MR30 turbine has been very consciously optimized to a conspicuous appearance similar to a power pole patina, suggesting the feeling that this wind turbine has been part of the landscape for a long time.