Impact of High Penetration Level of Grid-Connected Photovoltaic Systems on the UK Low Voltage Distribution Network

The connection and use of Renewable Energy Sources (RES) such as Grid-Connected Photovoltaic (GCPV) systems in distribution networks have been increasing over the last few decades. The grid-connected PV system is one of the most promising renewable energy solutions which could offer many benefits to both the end user and the utility network. Such systems may cover the consumer’s own power demand and reduce electricity bills, while feeding any surplus power into the grid or use the grid as a backup system in times of insufficient PV generation. However, integrating a high penetration level of small-scale grid-connected PV systems into the low voltage distribution network (LVDN) could cause operational problems. One of the technical issues is a possible voltage rise along distribution feeders as a result of reverse power flow, especially at low demand and high generation conditions. This paper assesses the effect of high penetration levels of small-scale gridconnected PV systems on the voltage quality of a residential electricity distribution network in the UK. Different scenarios for both penetration and solar irradiation level are considered under various loading conditions. The MATLAB/Simulink software package was used to carry out this assessment.