Large-eddy simulation of a utility-scale wind farm in complex terrain

Site-specific wind farm design must take into account the effects of site-specific terrain topography. Large-eddy simulation (LES) is a promising approach for simulating the site-specific characteristics of the wind fields and turbine wakes in complex terrain. However, to the best of our knowledge, the capability of LES in simulating utility-scale wind farms in complex terrain has not been systematically evaluated. In this work, we apply the state-of-art LES code Virtual Flow Simulator (VFS-Wind) to simulate the Invenergy Vantage wind farm (located in the Washington state, USA) in complex terrain. The computed power outputs are compared with field measurements and good agreement with the measured data is obtained both in terms of mean power and statistics of power generated by the wind farm. A simple analytical wind farm model without considering the complex terrain effects is also applied to predict the performance of the Vantage wind farm layout. The results show that such a model overestimates the performance of the actual Vantage wind farm and underscore the need for developing analytical models that account for terrain effects to enable wind farm design and optimization in complex terrain. LES can provide the data sets required to calibrate and validate such terrain-specific analytical models.