Post Construction Assessment

After making sure that the windiness of the period of operation is not the cause of the under performance, comparing the modelled and measured power curve of a wind farm (performance matrix) allows to check if the performance of the investment is as expected.
SCADA production data are binned by wind speed and direction derived from the measurement masts available at the site. Wake disturbed sectors are assessed following the Annex A of IEC61400-12-1. The measured performance matrix is obtained and the same procedure is used to derive a modelled performance matrix out from estimated production data.
The estimated production time series are obtained by modeling the orographic speedups between the wind measurement point and the hub of the turbines, applying such speedups to the wind time series, and calculating power time series using the declared power curve and subtracting possible wake losses.