Techno-economic feasibility of hybrid solar photovoltaic and battery energy storage power system for a mobile cellular base station in Soshanguve, South Africa

Abstract

Over the years, sustainability and impact on the environment, as well as operation expenditure, have been major concerns in the deployment of mobile cellular base stations (BSs) worldwide. This is because mobile cellular BSs are known to consume a high percentage of power within the mobile cellular network. Such energy consumption contributes to the emission of greenhouse gases (GHGs) through the use of conventional diesel generating set (gen-set). As a result, mobile cellular operators are faced with the dilemma of minimizing the power consumption, GHG emissions, and operation cost, while improving the quality of service (QoS) of the networks. In attempting to find a solution, this study presents the feasibility and simulation of a solar photovoltaic (PV)/battery hybrid power system (HPS), as a predominant source of power for a specific mobile cellular BS site situated in the Soshanguve area of the city of Pretoria, South Africa. It also presents the technical development and shows the environmental advantage and cost benefits of using a solar PV/battery HPS to power a BS site with a 24 h daily load of 241.10 kWh/d and peak load of 20.31 kW as compared to using the HPS with a solar PV/diesel gen-set/battery. The solar resource pattern for the city of Pretoria was collected from the National Aeronautics and Space Administration and was modeled statistically. The statistical modeling done using solar radiation resource exposure characteristic patterns of Pretoria, South Africa revealed an average annual daily solar radiation of 5.4645 Wh/m2/d and a 0.605 clearness index. The simulation and the design were done using Hybrid Optimization Model for Electric Renewables (HOMER) and Matlab/Simulink software. The simulation finding showed that the HPS of the solar PV/battery combination has about a 59.62% saving in the net present cost (NPC) and levelized cost of energy (LCOE) and an 80.87% saving in operating cost as against conventional BSs powered with a gen-set/battery.