Assessing the impact of distributing large grid-tied PV systems on network losses

Abstract

Various large solar plants have been connected to the grid in the recent years for example the Busitema Solar Plant (4MW), Tororo North solar Plant (10MW) among others with a co-joint role of minimizing losses on transmission lines through distributed generation, hence a reduction in the transmission distance. However, the losses remain significant due to some of the areas distributed to being at a considerable distance from the plant hence a longer transmission distance resulting into higher resistances. This study aims at how distributing the large grid-tied PV systems will help to minimize the losses further using a case-study of Busitema Solar Plant (4MW) and the Tororo-Busia 33KV feeder. The study consists of five chapters. Chapter One introduces us to the study, stating and providing a viable explanation for the existing problem, the main objective, specific objectives, research questions, the scope of the study, background, and justification of the study. Chapter two consists of the literature review with detailed explanations for the literature on network losses, how distributing large grid-tied PV systems helps to reduce losses on transmission and distribution lines by minimizing the I2R losses on the lines. This chapter also describes several factors behind the study which were majorly the increasing technical energy losses (around 16.4% p.a) despite several loss reduction methods available, which would not correlate with the increasing energy demand of Uganda’s population and the strategies of GOU to increase electricity access to about 60% by 2040. With the distribution of large grid-tied PV systems, the technical losses would be greatly reduced and the electrical power utilized would have increased. This chapter also presents the conceptual framework, which shows the inputs into the project to obtain a given set of results. An extract of the ERA net metering regulations which guide us on the eligibility requirements for the license of net metering in Uganda are also presented, limitations, and the maximum amount of power a prosumer can generate. Chapter three is the methodology which contains detailed explanations of the research design, research approaches, geographical area of study, measurements, data collection methods, and data analysis among others. This included the use of various data collection techniques such as literature review, surveying, and interviews among others. The research was majorly of a quantitative approach using quasi experimental/simulation as well as experimental designs to come up with the data. Surveys were conducted on the Tororo-Busia 33kv line to determine the number and size of the components on the line including the transformers, buses/nodes, switches and circuit breakers, generators, loads, xi capacitors, and reactors among others, and then a solar net-metering scheme was carried out using DIGISILENT software to assess the network losses and hence its benefits in a distribution network. Chapter four consists of the results and discussions of the study. And conclusions which shown that the losses decreased further on distributing large grid-tied Busitema Solar Plant (4MW) along the feeder are presented in chapter five together with the recommendations which were advocating for net metering on a large scale, improved monitoring systems due to changing production levels and leveraging the private sector dealing in Renewable energy. That way more power will be available for utilization by the ever-increasing population in Uganda.