As wind parks enter the commercialization phase, more detailed data is requiredthan that provided by the methodologies in use today. In particular, new windparks are likely to be installed in non-flat or complex terrain since most of thesuitable flat terrain sites have already been utilized.More reliable estimates of commercial viability are needed for these new sites tosatisfy business investment criteria. This requires more accurate confidence limitsand risk assessment, given the inherent variability of the resource, and long-termperformance analysis. This project aimed to address these concerns throughmethodologies for improved estimates of wind energy production, includingcomputation of uncertainty limits and expected variations, with particular emphasison sites within complex terrain.