Framework for policy prescription to sustainably steer stochastic penetration of electric vehicles and solar PV in distribution network of a developing country

Abstract

Cash-strapped distribution companies of developing countries face stochastic penetrations of solar photovoltaic units (PVs) and electric vehicles (EVs) while planning to manage their uncertain growth trajectories. Since Pakistan’s power distribution sector is not technically and financially sound, this research presents a framework for policy prescription to avoid dangerously burdening distribution companies or deteriorating the grid conditions. The EV load model considers EVs' arrival and departure times based on a survey of daily commuters. The Burr distribution function is used for selecting sizes of the PVs for grid integration because it best fits sampled data of installed PVs in the country. After stochastically selecting network nodes for integrating EVs and PVs to mimic their locational growth, technical and financial parameters are evaluated with and without the net metering effect. At peak PV hour and higher PV penetration of 50%, voltage limit conformance improves from 88% to 94% if net metering is not allowed. Results show that annual net revenue increases with rising EV penetration and always remains positive in the absence of PV. However, irrespective of EV penetration level, even 25% PV penetration and consequent loss of cash inflows lead to negative net revenues. The study concludes that excessive PV penetration with net metering causes voltage instability and negative net revenues, whereas EV integration can reduce both effects. A network-wide extension of our research methodology, to representative feeders selected by clustering, is proposed as a framework for policy prescription to steer the growth of EVs and PVs integration sustainably.