Optimal design of energy storage systems for stand-alone hybrid wind/PV generators

A major shortcoming in the exploitation of renewable energy sources relies in the effective power availability, that depends from the variability of the primary energy resource over the time. Because of the variability and unpredictability of primary power both photovoltaic arrays and wind turbines cannot ensure the minimum level of power continuity required to supply in island mode a generic set of residential loads. Therefore, they must be complemented with suitable energy storage devices to form a hybrid power generation system. The design of a hybrid generation system including energy storage devices is a quite complex task. A probabilistic design approach is then proposed in this paper based on the LPSP index. Such an approach is also used to detect the most advantageous combination of wind turbines, PV plant and energy storage system, for a stand-alone generator aimed to supply a small set of domestic loads.