The number of installations of photovoltaic solar panels and associated inverter systems within residential premises is increasing. As these systems incorporate a power electronics front end, they will have an influence on the quality of supply in regards to voltage harmonics. This paper investigates the harmonic impact on an LV distribution feeder due to the installation of residential type grid connected photovoltaic inverter systems. To undertake the study an aggregated current source model is proposed for the photovoltaic inverter systems based on measurement data from available literature and the relevant international standards. A typical LV distribution feeder including load arrangements is selected for the study. Conventional harmonic modelling methods are applied to determine harmonic emissions and resulting harmonic voltage levels for various penetration levels of photovoltaic inverter systems. Based on this study, a recommendation is made for acceptable penetration levels to limit the harmonic impact of grid connected photovoltaic inverter systems.