Distributed renewable PV generation in urban distribution networks

Distributed renewable PV generation, whose cost is slowly decreasing towards grid parity, may provide operational benefits in urban feeders: it could level the load curve, improve the voltage profile and reliability and reduce losses across the feeder, improve the transmission capacity margin, as well as provide environmental benefits. The small distributed renewable PV systems are normally not owned, nor operated by the utility; their output and the locations of individual systems, as well as their sizes and operational status, are not precisely known at the planning stage. The high level of uncertainty makes the planning more complex than in conventional distribution networks. Distributed generation and storage units may reduce the impact of faults on customers within their protection zones by creating islands of supply, thus increasing the reliability of service. However, such generation may be power and/or energy limited, and may not be able to exclusively serve their local loads at all times. The paper discusses the issues related to designing the feeders with distributed renewable generation and methodology for analysis of their operation.