Advancing solar energy financing in Sub-Saharan Africa: A systematic review of trends, progress, and pathways to sustainable development

Access to affordable and sustainable energy remains a significant development challenge in Sub-Saharan Africa (SSA), where over 600 million people lack electricity despite the region's abundant solar resources. Financing constraints, weak institutional frameworks, and high capital costs continue to hinder the deployment of solar energy technologies. This study assessed the evolution, trends, and key drivers of solar energy financing in SSA. Using the Scopus database, research publications from 1995 to 2025 were systematically screened in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses framework. Bibliometric analyses were conducted using the Bibliometrix package in R-Studio to map publication trends, country contributions, collaboration networks, and thematic evolution. The findings revealed growth in research output since 2019, demonstrating global interest in clean energy access. The United Kingdom and South Africa lead contributions, while Ghana and Nigeria are emerging hubs. Key research themes include energy access, renewable energy policy, financing models, and climate change mitigation. Persistent barriers, including high upfront costs, inadequate financial mechanisms, and institutional weaknesses, hinder investment flows. The study identified potential areas for future research on solar energy financing in SSA. The study's findings highlight the importance of innovative financing instruments, local capacity-building, and policy consistency in attracting private investment. These insights are crucial for policymakers, investors, and researchers aiming to develop inclusive, sustainable, and scalable solar energy financing frameworks in SSA.