Re-Analysis Data for Fine Temporal Resolution Wind Power Estimation: A Comparison of Boundary Layer Parameterizations

Under high wind energy penetration, short-term (intraday) and localized fluctuations are increasingly important for power systems planning and operation relative to typical measures of average annual availability. Global wind resource assessments have benefitted in recent years from re-analysis datasets, but these datasets typically have difficulty resolving boundary layer atmospheric stability dynamics, important drivers of wind power fluctuations. Leading methods to improve their accuracy such as downscaling are computationally expensive and geographically constrained. In this study, wind power densities constructed from Modern Era Retrospective-analysis for Research and Applications (MERRA) boundary layer flux data were compared to over 30 unassimilated wind measurement series, and systematic diurnal errors, in some cases larger in magnitude than aggregate annual errors, were identified. Comparing across geographies, these are attributed to diurnal changes in boundary layer height and stability. A heuristic method to incorporate these additional parameters is proposed and validated against a test dataset.