MeteoGroup has developed a technique to accurately estimate the confidence intervals of the wind speed, the wind direction and the power. These intervals are dynamically based, i.e., they depend on the observed synoptic situation. The estimation consists of the following parts: The optimal forecast is derived by combining multiple (global and regional) models. All 51 EPS members of the ECMWF are used to capture the uncertainty in the forecast of the wind speed and -direction Systematic biases between the ECMWF model and the observations are removed The optimal forecast of the power, as well as its uncertainty range, are derived by nearest-neighbor resampling from the observed power curve.
This advanced method enables MeteoGroup to supply accurate forecasts as well as realistic uncertainty ranges, both for wind speed, wind direction and power output. The method can be applied to individual turbines as well as to wind parks.