Statistical estimates of short duration power generated by a photovoltaic unit in environment of scattered cloud cover

• Statistical models for short duration generation at a PV station, with the relative optical air mass as a parameter.
• Closed form expression for statistical estimate of short duration mean output power and output power variability.
• Closed form expressions for statistical estimate of short duration power change distribution.
• Statistical estimates justified against empirical ensemble estimates reported in available literature.

The statistics of low level scattered cloud cover (cumulus or strato-cumulus types), is evolved to formulate analytical expressions for short duration mean output power and its variability, as well as power change distribution, at the output of photovoltaic generating stations. The proposed expressions are used to obtain statistical estimates of the three, which are substantiated by comparison to empirical ensemble estimates reported in available literature.The strength of concepts and formulations presented in the paper is their dependence on a single aggregated meteorological parameter, namely the optical air mass. Their applicability therefore spans over a range of PV generation plants regardless of geographical and weather conditions.