Need for a traceable efficiency determination method of nacelles performed on test benches

For an energy transition towards renewable energy sources, the importance of traceable efficiency determination increases. There are standards for a traceable efficiency determination of rotating electrical machines as well as standards for a power curve determination of wind turbines in the field. To speed up and ameliorate the design process of a wind turbine, however, a standardised efficiency determination method for nacelle drive trains on test benches is required. In this paper, the need and recommendations for such an efficiency determination method are given.