Das Projekt "Monopteros 50 for electricity production" wird vom Umweltbundesamt gefördert und von Jade Windenergie Wilhelmshaven GmbH durchgeführt. Objective: A 640 KW Monopteros, horizontal axis, one-bladed wind turbine will be constructed by MBB using the experience gained from the M400 wind turbine, aiming to bring this design to series-production in the future. It will be grid connected and will be installed at Einswarden. The estimated annual yield is 1960 MWh. General Information: The Monopteros 50 will be designed and constructed by MBB and will be installed at Einswarden and will be connected to the local grid. The main characteristics of this machine are: - the horizontal axis, one blade, downwind rotor with a teetering hub, - the soft tower concept, - the variable speed drive train generator concept, - active controlled yaw angle during operation, passive in parking position, - dimensions and weight of the components enable easy installation. The 640 KW machine is based on a 60m height free standing steel tower. The rotor blade is built in an all-composite shell construction with a supporting foam core without any secondary structures. Glass reinforced plastic is used. The generator system is an AC-DC-AC system consisting of a synchronous generator. The cut in speed is 6 m/s, the rated speed 11 m/s and the cut-out speed 16 m/s. The cost of KWh produced is estimated at 0,21 DM while the conventional KWh is 0,23 DM. With an annual yield of 1750 MWh (90 per cent availability) the pay back time has been estimated to 12 years. Achievements: Three of these 640 kW Monopteros 50 wind turbines have been installed at Wilhemshaven in October 1989 and since then there are in operation. In the first 22 months of operation, one of the WTs was in operation for 5096 hours and produced 2535 MW. Very impressive information center near the installation site visited by 12000 visitors each year. The concluding remarks about the assessment of this project must be coloured by the fact that MBB is not longer involved in Wind Energy. It has decided that there is no commercial future for its technology. The only remaining activity within the European Community, which is linked to the activities of MBB in the past is that of Riva Calzoni in Italy. The most important positive outcome of this project is the fact that it has been visited by 50 many people, who have had a useful and informative introduction to the technology.