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As a consequence of the rapid growth of the globally installed offshore wind energy capacity, the size of individual wind farms is increasing. This poses a challenge to models that predict energy production. For instance, the current generation of wake models has mostly been calibrated on existing wind farms of much smaller size. This work analyzes annual energy production and wake losses for future, multi-gigawatt wind farms with atmospheric large-eddy simulation. To that end, 1 year of actual weather has been simulated for a suite of hypothetical 4GW offshore wind farm scenarios. The scenarios differ in terms of applied turbine type, installed capacity density, and layout. The results suggest that production numbers increase significantly when the rated power of the individual turbines is larger while keeping the total installed capacity the same. Even for turbine types with similar rated power but slightly different power curves, significant differences in production were found. Although wind speed was identified as the most dominant factor determining the aerodynamic losses, a clear impact of atmospheric stability and boundary layer height has been identified. By analyzing losses of the first-row turbines, the yearly average global-blockage effect is estimated to between 2 and 3 %, but it can reach levels over 10% for stably stratified conditions and wind speeds around 8 ms-1. Using a high-fidelity modeling technique, the present work provides insights into the performance of future, multi-gigawatt wind farms for a full year of realistic weather conditions. [ABSTRACT FROM AUTHOR]

In this article the aeroelastic loads on a 10MW turbine in response to extreme events (low-level jet, shear, veer and turbulence intensity) selected from a year-long large-eddy simulation (LES) on a site at the North Sea are evaluated. These events are generated with a high-fidelity LES wind model and fed into an aeroelastic tool using two different aerodynamic models: a model based on blade element momentum (BEM) and a free vortex wake model. Then the aeroelastic loads are calculated and compared with the loads from the IEC standards. It was found that the loads from all these events remain within those of the IEC design loads. Moreover, the accuracy of BEM-based methods for modelling such wind conditions showed a considerable overprediction compared to the free vortex wake model for the events with extreme shear and/or veer. [ABSTRACT FROM AUTHOR]