Computer simulation of atmospheric flows over real forests for wind energy resource evaluation

The increased number of wind parks and the shortage of ideal sites have forced us to consider the possibility of installing wind farms in the vicinity of or within forests. Measured wind data at two potential wind farm sites, in Scotland and in France, were used for appraisal of a computer model of the wind flow over forested regions, where the trees are mimicked by momentum sinks. The results of the Scottish case were an improvement over previous computer simulations without the canopy model, and showed the difficulties of comparing detailed three-dimensional computer simulations with field data point measurements. In case of the French site, agreement was excellent between mean velocity field measurements at seven heights above the ground, between 40 and 100 m, and computer results. It was found that the presence of the canopy could increase the turbulence levels by almost two orders of magnitude, when compared to the results obtained without the canopy model.