Quantifying Variability for Grid-connected Photovoltaics in the Tropics for Microgrid Application

This paper quantifies the variability of solar resource for PV systems located in the tropical climate. Global horizontal irradiance data is obtained from a site in Melaka, Malaysia with one-minute-average values for a full year. Clearness index and variability index are used together with a clear sky model for tropical location to classify the days according to its fluctuation profile. The results show that significant amount of variability occur throughout the year for this site while days with clear skies are almost negligible. PV can potentially supply part of the loads during the day but precise planning on storage and backup generators is crucial for independent microgrid operation.