Power quality performance assessment of stand-alone minigrids in Kenya

Publication Type

Journal Article

Name of Author

• Duncan Nkolokosa, Department of Physics, University of Nairobi, Box 30197-00100, Nairobi, Kenya Basic Sciences Department, Lilongwe University of Agriculture and Natural Resources, Box 219, Lilongwe, MalawiFollow
• Sebastian Waita, Department of Physics, University of Nairobi, Box 30197-00100, Nairobi, Kenya
• Mutugi Kiruki, Department of Electrical and Information Engineering, University of Nairobi, Box 30197-00100, Nairobi, Kenya

Publication Date (Issue Year)

2026

Journal Name

Renewable Energy Focus

Abstract

Global rural electrification initiatives have accelerated the deployment of renewable energy-based minigrids. However, their performance is highly susceptible to weather dynamics, which adversely affect power quality and service delivery. This study presents a comprehensive analysis of power quality in autonomous minigrids. The assessment was conducted on eleven autonomous minigrids in remote regions of Kenya. Structured questionnaires were administered across all sites, while detailed power quality logging was performed at six selected sites using a Fluke 1777 power quality analyzer for one week per site. Novel integrated fuzzy framework was developed using Weighted Sum Method (WSM), Fuzzy AHP, and AHP + CRITIC to compare overall minigrid performance. Robustness of the final ranking was tested via one-at-a-time sensitivity analysis (±20% weight perturbation) and Monte Carlo simulation (10,000 iterations, 95% CI). Results revealed significant variations, the highest average power factor was recorded at Ndeda Island (0.89), while Illaut (0.61) and Remba Island (0.51) exhibited very poor power factors. Frequency variations at Locheromoit (0.52), Ndeda (0.59), and Remba (1.2) exceeded EN 50160:2010 and IEEE 519-2022 thresholds. Substantial prolonged interruptions were observed at Hadado (1.2 hrs/week) and Illaut (2.59 hrs/week). Unlike Wasini that achieved the highest FTPQI (0.93), Illaut registered the lowest FTPQI (0.29). Wasini and Illaut demonstrated 100% rank stability under ±20% perturbation. Spearman correlations between WSM vs. AHP+CRITIC and FAHP vs. AHP+CRITIC were 0.89 and 0.94, respectively. The findings demonstrate that fuzzy power quality indices are critical for diagnosing specific failures, particularly poor power factor, frequency instability, and prolonged interruptions in autonomous minigrids.

Keywords

Fuzzy logic, Minigrid, Power factor, Power quality index, Stability, Energy access

Rsif Scholar Name

Duncan Nkolokosa

Rsif Scholar Nationality

Mali

Cohort

Cohort 4

Thematic Area

Energy including Renewables

Africa Host University (AHU)

University of Nairobi (UoN), Kenya

Recommended Citation

Nkolokosa, D., Waita, S., & Kiruki, M. (2026). Power quality performance assessment of stand-alone minigrids in Kenya. Renewable Energy Focus, 60 https://doi.org/10.1016/j.ref.2026.100924