Optimisation of GRID stability in Uganda through vehicle-to-GRID technology

Abstract

The growing adoption of Electric Vehicles (EVs) presents both opportunities and challenges for power systems, particularly in developing countries like Uganda, where grid infrastructure is relatively weak. This study investigated the potential of Vehicle-to-Grid (V2G) technology to optimize grid stability in Uganda by addressing voltage deviation and peak demand issues. A quantitative approach was employed, combining empirical data collection with simulation-based modeling and statistical analysis. Charging data from Kayoola electric buses with real-world load profiles from the 55 MVA Kisugu substation in Kampala were analyzed to assess baseline grid stress. Simulations were performed using MATLAB/Simulink (R2024a), complemented by statistical correlation analysis, probabilistic modeling with the Weibull distribution, and optimization through a rule-based control algorithm. The results demonstrate a statistically significant correlation between EV charging and peak demand (r = 0.68, p < 0.05), confirming that EV charging can contribute to grid stress. Voltage drop simulations revealed that under peak demand conditions, deviations exceeded Uganda’s 5% regulatory threshold, reaching as high as 10.4% in the assessed daily load profile. With V2G integration, voltage drops were significantly reduced, falling within acceptable limits across the intervals. The optimal V2G strategy was based on predefined voltage deviation thresholds and real-time control of EV discharge, factoring in fleet size and State of Charge (SOC). For the daily load profile considered, a coordinated fleet of 54 EVs, each maintaining a minimum SOC of 73.33%, collectively was required to supply up to 14.72 MW of power to stabilize the grid during peak demand. The study concludes that V2G technology offers a technically viable and contextually relevant solution for improving grid resilience in Uganda. Recommendations are provided for improving access to high-resolution grid data, piloting V2G operations, and exploring policy frameworks that align with Uganda’s operational realities. The findings contribute a localized and data-driven reference model for V2G deployment in Sub-Saharan Africa, helping to fill a critical gap in the global literature on EV-grid integration.