Effects of distributed PV generation on California’s distribution system, Part 1: Engineering simulations

•We model 8 feeders in 3 climate regions with data from real distributed PV systems.•Location more strongly influences reverse flow, peak loading and voltage excursions.•Feeder characteristics more strongly influence losses, voltage regulator operations.•In general impacts are small, even up to 100% PV penetration.

Deployment of high-penetration photovoltaic (PV) power is expected to have a range of effects – both positive and negative – on the distribution grid. The magnitude of these effects may vary greatly depending upon feeder topology, climate, PV penetration level, and other factors. In this paper we present a simulation study of eight representative distribution feeders in three California climates at PV penetration levels up to 100%, supported by a unique database of distributed PV generation data that enables us to capture the impact of PV variability on feeder voltage and voltage regulating equipment. We find that feeder location (i.e. climate) has a stronger impact than feeder type on the incidence of reverse power flow, reductions in peak loading and the presence of voltage excursions. On the other hand, we find that feeder characteristics have a stronger impact than location on the magnitude of loss reduction and changes in voltage regulator operations. We find that secondary distribution transformer aging is negligibly affected in almost all scenarios.