Urban–Rural Comparative Assessment of Hybrid Energy Systems in Southern Africa: A Systematic Review and Bibliometric Analysis

Abstract

Urban electricity systems in Southern Africa are characterized by persistent grid unreliability, ageing infrastructure, and continued dependence on fossil fuels, despite substantial renewable energy potential. Hybrid energy systems (HES) have emerged as a pathway to enhance urban energy resilience, reduce costs, and support decarbonization. However, despite high urban electricity access, they remain underexplored relative to rural systems, limiting their role in addressing urban reliability challenges. This study presents a systematic review and cross-country synthesis of urban-rural HES deployments in Southern Africa between 2010 and 2025, focusing on dominant system configurations, modes of integration, sectoral applications, and techno-economic and environmental performance. Findings show that PV–battery(–grid) systems dominate urban deployments, particularly in South Africa. More complex systems incorporating biomass, hydrogen, pumped hydro, or concentrated solar power remain scarce in urban contexts. Reported levelized cost of electricity ranges from $0.009 to $1.13/kWh, with a mean of $0.18/kWh. Net present cost spans $662 to $111.8 million, while financial savings range from $30,207 to $953,564 (14.4%–69.3%). Environmental performance is more consistent, with CO₂ emission reductions of 56.8%–90.3% and renewable fractions of 42–100%. Overall, the urban HES demonstrates strong decarbonization potential alongside improved economic viability, while highlighting the need for standardized reporting and supportive policy frameworks.