Comparisons of the wind trends from MERRA2 data and a multisource wind index (23 regions in Europe): Why does the choice of the reference sources matter so much?

摘要

The long term prediction of the wind resource is one of the key issues of energy yield assessments, and often explains the main deviations between several studies for a given project. In order to assess to what extent the choice of the long term reference sources can lead to deviations in terms of estimated long term production, a comparative analysis was carried out between wind speed trends obtained via MERRA2 data and a multisource index for 23 regions in 6 European countries, This multisource index is considered as the reference as it results from the combination of measured wind data by ground stations, rigorously selected to be coherent between each other and consistent over the long term period considered (cross-checking of convergent and independent information). The comparison was carried out for the period 2000-2017 (18 years) over 23 areas in Europe: 8 in France, 5 in Germany, 5 in the UK, 3 in Denmark, 1 in the Netherlands and 1 in Belgium. These analyses have shown different conclusions from one area to another. In most regions the long term trends proposed by MERRA2 data are very similar to the reference one. Some punctual differences can lead to significant deviations in terms of long term prediction, but they are limited to several specific years. However, in some particular regions, a significant deviation in the long term trend proposed by MERRA2 data can be observed. The areas considered for the analysis are displayed on the map above, as well as the location of the ground stations (blue icons) and the MERRA2 simulations (pink icons).