BS EN 61400-12-1. Wind turbines. Part 12-1. Power performance measurements of electricity producing wind turbines Wind turbines, Turbines, Electric generators, Wind-electric power stations, Wind power, Winds, Power measurement (electric), Performance testing, Power output, Velocity measurement, Testing conditions, Test equipment, Mathematical calculations, Accuracy, Calibration, Sensitivity, Environment (working), Site investigations, Error correction, Classification systems, Formulae (mathematics), Reports, Statistical methods of analysis, Data processing, Measurement characteristics