Performance Evaluation of Solar Roof-Top PV on Eskom's LV Electric Power Distribution Networks

Abstract

The South African government policy to electrify all customers has placed immense demands on the electricity infrastructure. Several new connected customers in line with these government targets and plans are in networks that are already constrained, with the consequence of violating statutory performance requirements and electrical parameters, such as thermal loading, voltage limits and technical losses. Utilities' solutions to remedy these problems sometimes requires huge investments to upgrade infrastructure and this may take years for implementation. In many instances, short-term solutions are available and feasible. This study investigates Solar Roof-Top PV (RTPV) as a renewable energy resource for reticulation (11/22KV) networks. Currently RTPV is not well documented and guided when considering available Grid codes, Guidelines and Standards. This paper demonstrates that RTPV penetration is more worthwhile to consider than capital strengthening/refurbishment projects. The study demonstrates the supportive role of RTPV to meet electrification demands. With increased penetration of RTPV's on distribution networks, there is a benefit to the feeder tail-end voltages with reduced thermal loading and technical losses in distribution networks. This provides Utilities with the opportunity to electrify more customers and defer capital expenditure, while reducing the carbon footprint. The balance of the paper presents an accurate view of RTPV analysis, attributed to the accuracy of data, by using a practical network topology coupled with its related statistical loading. It further takes into account the associated customer connected at the LV transformers. With the imminent influx of RTPV, the results of this study will assist in equipping the South African Electricity Supply Industry (ESI) for the readiness of RTPV and the influence of RTPV on reticulation networks by quantifying the impacts and expectations for the Electric Power Utility and the customer.