Mini-grid performance in Sub-Saharan Africa: case studies from Tsumkwe and Gam, Namibia

Introduction

This page summarises the open-access empirical study by Mehta et al. (2025) evaluating the operational performance of two community mini-grids in Namibia (Tsumkwe and Gam). The study provides detailed operational data, root-cause analysis of failures and practical recommendations for improving reliability and economics of rural mini-grids in similar environments.

Project Context

Locations: Tsumkwe and Gam, remote communities in Namibia. Systems: Hybrid mini-grids combining solar PV arrays, battery storage and diesel backup; systems supply residential, community and limited commercial loads.

Data & Methods

Field monitoring data (generation, storage state, load profiles) and site inspections were used. Interviews with operators, community representatives and maintenance logs informed operational diagnosis.

Key Operational Findings

Battery degradation: Elevated ambient temperatures and inconsistent maintenance reduced battery life, increasing replacement costs. Demand dynamics: Early years saw lower-than-expected demand; subsequent household uptake and productive use caused demand growth, occasionally exceeding design capacity. Diesel reliance spikes: During periods of low renewable yield or battery failure, diesel backup use rose sharply, increasing operating costs and emissions. Maintenance gaps: Reactive maintenance dominated; preventive maintenance schedules and remote monitoring were found to improve uptime.

Lessons Learned & Best Practices

Thermal & battery management: Protect batteries from extreme heat, implement cooling solutions, and adopt conservative depth-of-discharge strategies to extend life. Scalable design: Use modular add-on capacity so systems can grow with community demand without large upfront oversizing. Monitoring & O&M contracts: Remote monitoring with clear O&M responsibilities reduces downtime; performance-based service contracts improved reliability. Community engagement: Strong community governance and transparent tariff policies improved payment rates and local caretaking of equipment.

Implications for Planners & Funders

Capital planning should factor realistic battery replacement cycles—higher ambient temperatures necessitate more frequent replacements or upgraded battery chemistries. Financing instruments must cover replacement cycles and incentivize preventive maintenance. Project procurement should include clauses for capacity expansion and clearly define grid-arrival compensation mechanisms.

References

Mehta K, Lwakatare B, Zörner W, et al. (2025). Mini-grid performance in Sub-Saharan Africa: case studies from Tsumkwe and Gam, Namibia. Sustainable Energy Research / SpringerOpen. (Open access, CC BY 4.0).

Attribution & Licence

This page summarises Mehta et al. (2025). The original article is licensed under Creative Commons Attribution 4.0 International (CC BY 4.0).