Assessment of the uncertainty of methods for the extrapolation of wind data to the long term
Assessment of the uncertainty of methods for the extrapolation of wind data to the long term
Sites: Several sites in different European regions with relatively long measured wind data sets
Method:
Calculation of the average wind speed of the entire measurement period based on the data of individual 12-months periods
Results:
The standard error of the long term mean wind speed determined with the MCP method and the MDP method developed by aj based on time series of 12 months is about 0.1 m/s.
With linear regressions over monthly means, the uncertainty is higher. Strongly deviating results occurred in some years with this method.
Based on hourly means, the long term mean wind speeds determined with the MCP method and the MDP method are usually very similar.
The MCP method allows for calculating a long term time series, whilst the MDP method yields a more accurate long termn frequency distribution and wind rose.
Gaps in the reference data set can have an important impact on the result.
In 2019, a wind measurement with a Sodar was completed successfully in the high mountains of Bosnia under winterly conditions. In 2019, a wind measurement with a Sodar was completed successfully in the high mountains of Bosnia under winterly conditions. In 2019, a wind measurement with a Sodar was completed successfully in the high mountains
aj completes successfully a wind measurement with Sodar to assess the wind shear on a site in Marocco. aj completes successfully a wind measurement with Sodar to assess the wind shear on a site in Marocco.
Oldershausen, 15 May 2018: A new study of aj shows that the wind resource of the years around 1990 cannot be considered as very exceptional any more. Consequently, these years must be included in the long term reference period, if the result should be balanced. Download of the report Wind D NAO-Index E 15.05.2018 aj