Least-cost electrification pathways for Senegal by 2030: A nationwide analysis using open-source spatial electrification tool (OnSSET)

Achieving universal electricity access in Senegal by 2030 remains a major policy challenge due to persistent spatial disparities in infrastructure, population density, and resource availability. This study conducts a nationwide, spatially explicit assessment of least-cost electrification pathways using OnSSET. The analysis develops context-specific scenarios to plan optimal technology mixes across rural and peri‑urban areas, based on differentiated tiers of electricity access. By integrating high-resolution geospatial, demographic, and techno-economic data, the model identifies the most economically viable solutions for achieving universal access. Results indicate that grid extension is the least-cost option for approximately 93.7 % of the population, largely concentrated in peri‑urban areas with high population density and proximity to existing grid infrastructure. In contrast, solar PV mini-grids (MG PV) and stand-alone PV (SA PV) systems are optimal for 0.7 % and 5.6 % of the population, respectively, mainly in remote, sparsely populated rural settlements. The total investment required to achieve universal electricity access by 2030 is estimated at USD 269.8 million, corresponding to 116.1 MW of additional installed capacity.Beyond quantifying cost-optimal solutions, the study demonstrates the potential of open-source geospatial models like OnSSET to support transparent, data-driven planning in developing country contexts. It also highlights key policy implications, emphasizing the need for integrated national electrification strategies that combine centralized and decentralized systems to address regional disparities. Limitations of the study include uncertainties in input data quality, static demand assumptions, and the exclusion of non-technical barriers such as institutional capacity and financing constraints. Nonetheless, the findings provide a valuable decision-support basis for Senegal’s ongoing energy transition and broader Sustainable Development Goal 7 (SDG7) objectives.