Effects of high solar photovoltaic penetration on distribution feeders and the economic impact

Abstract

Significant growth in PV penetration worldwide has introduced intriguing challenges for power utilities and consumers alike. This include financial losses resulting from overvoltage-induced PV curtailment during times of high PV generation. This paper examines these issues by first developing a methodical approach to quantify the impacts of PV penetration in terms of reverse power flow, overvoltage and undervoltage events. A real distribution feeder in South Australia is analysed against various PV penetration levels. The simulation model developed utilises residential load profile of South Australia and voltage regulation limits of the feeder and the inverter as set by the Australian standard. Results show that increase in PV penetration reduces the instances of undervoltage, however the instances of overvoltage increase substantially. The latter leads to inverter shutdowns when the voltage exceeds the nominal maximum voltage of the inverters. Maximum possible PV generation loss due to inverter shutdown is evaluated and some recommended solutions are presented. The financial loss due to PV curtailment has been estimated from different perspectives, namely, using feed-in-tariff, retail price and the pool price (market price). In the context of rapidly evolving regulatory frameworks and financial models for renewable energy, power utilities will need to take these financial losses into account when conducting cost-benefit analysis for possible network upgrades for increasing the PV hosting capacity of the network.