Impact of the Wind Geographical Correlation Level for Reliability Studies

Following several governmental policies trying to reduce CO emissions, renewable energies have been largely promoted during the last decade. Among the green energies that have been developed, wind can actually be seen as one of the most promising solution if we refer to its past and predicted evolutions. However and, even though wind can be considered as an interesting alternative to fossil fuels, it is imperious to emphasize on problematic situations that could be due to the intermittent behavior of wind generation. Indeed, actually, most of the electric utilities do not consider wind power in the classical units management; consequently involving, in the case of increased wind power penetration, untimely stopping of big thermal (or nuclear) units. It is, therefore, necessary to calculate wind equivalent capacities in order to introduce a coherent evaluation of wind production in the management of the centralized production park. In this paper, wind equivalent capacities are calculated using a nonsequential Monte Carlo Simulation. Moreover, in order to evaluate the importance of the wind correlation level between parks located in the same geographical region, two cases are investigated, respectively considering entirely correlated wind parks and, on the opposite, totally independent wind sites. Finally, simulation results show that durations of simultaneous zero wind power production for each considered wind parks stay, in both cases, very low involving quasi-identical calculated equivalent capacities; what tends to demonstrate the minor importance of the wind parks correlation level for wind power estimation in reliability studies. Note that, here, the proposed conclusions are obtained using the Belgian production park data and that the objective is not to dynamically estimate wind production on the short-term (by the use of an autocorrelation function) but rather to give a simplified way to introduce an hourly evaluation of wind production in the day by day management of the classical thermal (nuclear) units.