The impact of utility-interactive residential photovoltaic (PV) power systems on the electric utility was studied. Power flow analyses were performed before and after the introduction of PV, on a subtransmission and distribution network model of an actual residential utility feeder serving a suburban area of Helwan in Cairo, Egypt. The changes in bus voltages and utility power factor were used to assess the impacts caused by the PV introduction. PV systems were examined at different penetration levels and were introduced in the low- and high-voltage buses of the distribution circuit. PV power factors as low as 0Â·7 were used to account for various power conditioner designs. PV-utility interconnection at the high-voltage distribution level is recommended since it results in acceptable voltage regulation throughout the network as well as a good utility power factor.