Abstract
With rising energy costs and the need for sustainable power solutions in urban South
African settings, grid-tied renewable energy systems have become viable alternatives
for reducing dependence on traditional grid supply. This study investigates the technoeconomic
feasibility of a grid-connected hybrid photovoltaic (PV) and battery storage
system designed for a commercial facility located in Johannesburg, South Africa—an area
characterized by a subtropical highland climate. We conducted the analysis using the
HOMER Grid software and evaluated the performance of the proposed PV/battery system
against the baseline grid-only configuration. Simulation results indicate that the optimal
systems, comprising 337 kW of flat-plate PV and 901 kWh of lithium-ion battery storage,
offers a significant reduction in electricity expenditure, lowering the annual utility cost from
$39,229 to $897. The system demonstrates a simple payback period of less than two years
and achieves a net present value (NPV) of approximately $449,491 over a 25-year project
lifespan. In addition to delivering substantial cost savings, the proposed configuration
also enhances energy resilience. Sensitivity analyses were conducted to assess the impact
of variables such as inflation rate, discount rate, and load profile fluctuations on system
performance and economic returns. The results affirm the suitability of hybrid grid-tied
PV/battery systems for cost-effective, sustainable urban energy solutions in climates with
high solar potential.