Modelling the technical influence of randomly distributed solar PV uptake on electrical distribution networks

Abstract

This paper investigates network integration of distributed rooftop PV systems on three distribution networks (one residential, one commercial and one industrial) in Cape Town, South Africa. A methodology is developed that can be used to model the technical influence (focusing solely on voltage rise and equipment overload) of randomly distributed solar PV uptake on electrical distribution networks. For the residential- and industrial area, the amount of PV-eligible roof space provides potential PV generation capacity that far exceeds the load requirements of the area. It is shown that allowable PV installations on the residential LV networks vary between 187 kW – 373 kW, and allowable PV penetration levels vary between 82% - 150%. The industrial network has the lowest allowable PV penetration level (31%), whilst the commercial area experiences no limit to the uptake of PV, since there is not enough PV-eligible roof space, and subsequent potential PV generation capacity, to cause network problems. This paper concludes guidelines as to the PV hosting capacity of the sample networks. The results of this paper provide a better understanding to utilities in terms of the technical limits that dictate PV uptake for different types of networks, as well as the corresponding PV penetration levels.