Validation of a Spanish regional high-resolution database for wind energy applications

The feasibility low carbon power systems (LCPSs) is challenged under high penetration rates of renewables because the inherent variability of renewable sources increases the system’s operation and transmission costs. Optimizing the operation of the systems to make them efficient and profitable requires adapting their design to the regional solar and wind patterns. The MET4LOWCAR Spanish project aims at demonstrating the benefits of the design of the LCPSs that accounts for the regional climatic patterns of both solar and wind renewable resources, using the Spanish territory as a testbed. To that aim, a 30-yr weather integration is being performed with the Weather Research and Forecasting (WRF) model over the Iberian Peninsula and the Balearic Islands throughout a 5-km spatial grid and a 10-min temporal grid (Regional reanalysis). The ultimate goal is to compound a climatic data base of solar- and wind-related variables to simulate the performance of a high-penetration LCPS in multiple scenarios, from long runs to extreme weather events.

 

In this work, the results of the assessment of the wind speed and wind power estimates derived from this regional reanalysis are presented and discussed. Different validation studies were conducted. Firstly, the wind estimates at 10 and 40 m a.g.l. were evaluated based on wind measurement collected at 44 surface meteorological stations and two masts located at wind farms. This study was conducted for years 2019 and 2020. In a second study, regional wind power models for 42 continental Spanish provinces were built and evaluated. Models were obtained using reference power curve and the regional installed capacities, elaborated based on information from wind farms at 506 locations collected from public databases. This study was carried out for the year 2020 at hourly resolution and the model estimates were evaluated based on actual power generation values provided by the Spanish TSO. Finally, wind and wind power estimates derived from the ERA5 reanalysis were also obtained and used for benchmarking purposes.

Results of the wind speed validation show a superior performance of the regional reanalysis for complex topography locations (where most of the Spanish wind farms are located). For instance, differences in the wind speed RMSE values greater than 2 m/s (4.27 vs 2.14 m/s) were found for one mast. Nevertheless, the overall performance of both reanalysis are similar (1.6 m/s mean RMSE value for surface stations). Results of the wind power modeling show a similar overall performance of both reanalysis. Nevertheless, wind power estimates derived from the regional reanalysis were able to better reproduce the wind power intra-day variability.