Quantifying Seasonal Impacts on Distribution Network Reliability: A Statistical Analysis of Outage Frequency in the Auchi 11 kV Feeders, Nigeria

Abstract

This study provides an empirical analysis of the impact of seasonal climate variability on power supply outage frequency within the Auchi distribution network, Edo State, Nigeria. Employing a quantitative research design, we analyzed historical outage data (2021-2023) for three key feeders—Auchi Town, Jattu, and Auchi GRA—sourced from the Benin Electricity Distribution Company (BEDC). Outages were classified by fault type and season (wet: April-October; dry: November-March). Descriptive statistics and a Chi-square test for independence were applied to the outage counts. The analysis reveals a statistically significant dominance of wet-season outages, with 63.8% of all outages occurring in this period, compared to 36.2% in the dry season (χ² = 81.0, p < .001). Weather-sensitive faults exhibited dramatic seasonal variation; for instance, Earth Faults were 4.2 times more frequent network-wide during the wet season. Notably, Load Shedding, the most common fault type, also peaked in the wet season, suggesting indirect climate impacts on generation and transmission. The findings underscore the acute vulnerability of the network to wet-season conditions and highlight the imperative for pre-emptive, climate-resilient infrastructure upgrades and seasonally-targeted maintenance strategies to enhance reliability.