A cost-effective PV-sizing approach based on the solar radiation statistical fluctuations

This paper presents a new PV sizing methodology, based not only on the mean expected values of the daily solar radiation on the PV array but, also, on the statistical fluctuations of the solar radiation on an hourly and daily basis of the site concerned. The fluctuations of the global hourly solar radiation are processed, and the results are used in this PV sizing methodology. In this methodology, the concept of the energy independence for d days of a stand alone PV plant, in contrast to the conventional PV sizing, does not influence directly the estimation of the peak power and the battery storage system, but indirectly through the concept of the 95% probable energy deficit. The estimated peak power and battery storage capacity are much lower compared to sizing results obtained by methodologies existing in the literature. The methodology presented in this paper has two characteristics: (1) a correction term in the conventionally estimated peak power, related to the ration of the standard deviation of the daily solar radiation over the mean solar radiation at the site. (2) the concept of the effective Load that the stand alone PV plant has to meet. The effective load is related to the standard deviation of the solar radiation fluctuations. A comparison of PV sizing results obtained by the methodologies as in literature and the one presented in this paper, is shown, for various values of meteorological parameters for the case of W. Greece.