Coupling the actuator line method to the high order meteorological les model Meso-NH to study wind farm wakes impacts on local meteorology

Abstract

Offshore wind energy is now reaching the technological maturity, its capacity is increasing all over the world and this trend is projected to continue for several more years. Given this expectation, a better understanding of the relationship between the presence of wind farms and the atmospheric boundary layer is needed. Turbulent wakes produced by wind turbines can significantly impact the flow dynamics within wind farms and downstream of them. Operating offshore parks have already shown losses on energy production and effects on the local climate. In order to analyse the interactions occurring during these impacts, a new tool has been developed. This numerical tool is a coupling between the Actuator Line Method (ALM) and the open-source, non-hydrostatic mesoscale atmospheric model Meso-NH, based on the Large Eddy Simulation (LES) framework. The coupled Meso-NH + ALM system is first validated by using the experimental data obtained during the New MEXICO experiments. In particular, simulated and experimental loadings along the blades are compared. Then, a simulation of an idealized Horns Rev wind farm is performed using met mast measurements and reanalysis data for the “Horns Rev 1 photo case” as initial conditions. This new coupled system allows the exploration of the impact of wind farms on the lower levels of the atmosphere.