Improvement of AEP Predictions with Time for Swedish Wind Farms

Based on data from 2083 wind turbines installed in Sweden 1988 onwards, the accuracy of predictions annual energy production (AEP) project planning phases has been compared to actual wind-index-corrected production. Both electricity and predicted AEP come Vindstat, a database that collects information directly turbine owners. The mean error for all analyzed was 13.0%, which means that, overall, overestimated. There an improvement with time overestimation 8.2% 2010s, however, continuous seems have stagnated around 2005 despite better availability refinement methods. Dividing results by terrain, is larger open flat terrain than forest areas, indicating reason behind not higher complexity terrain. Also, there no apparent increase farm size could expected if blockage effect main overestimations. Besides inaccurate predictions, higher-than-expected performance decline due inadequate maintenance may be sources are insecurity regarding source omission mid-life alterations rated power.