Complex mountain winds provide a wind energy potential, which is still largely unknown. Mountainousterrain forces air flow to react by e.g., wind flow sheltering, strong ridge acceleration, channelling, deflections,blocking and even recirculation. Thermally driven circulations add to that complexity and arealmost always connected with topography-modified wind flows (Whiteman, 2000). Diurnal changes inwinds, due to horizontal temperature differences, lead to characteristic mountain wind systems suchas the "slope wind" system or the "mountain -valley wind" system. The impact of these complex topographyeffects on annual energy production (AEP) has not been thoroughly quantified yet and may beconsiderable. For instance, compared to the lowlands, wind speeds were found to generally increasewith terrain elevation in mountainous terrain, and this is even more prominent in the winter, when moreenergy production is required (Kruyt et al., 2017).
