Burkina Faso's electricity sector faces rising demand and frequent outages, with targets to expand solar photovoltaic (PV) capacity as part of its renewable energy strategy. Nevertheless, the fragile electrical grid infrastructure and constrained backup generation capacity create uncertainty regarding large-scale solar PV deployment without significant financial investment. Operational constraints and transmission-line expansion are often neglected in long-term planning through network simplification, leading to underestimated investment needs. This paper develops a capacity-expansion model that integrates operational constraints and incorporates a nodal transmission representation starting from existing infrastructure to identify required incremental capacities. Using clustered unit commitment and representative days, we evaluate coordinated PV–storage–import expansion pathways and quantify their cost and infrastructure implications. The results reveal that meeting PV targets raises capital expenditure by 21% and total system cost by 7%, requires upgrades to six transmission corridors, and sustains reliance on fossil oil plants and imports. Including storage reverses this trajectory: initial storage deployment reduces oil-based generation, increases PV investment, and limits transmission upgrades to two corridors. Storage-inclusive scenarios decrease overall system expenses by 47%, lower levelized cost of energy (LCOE) by ~56% relative to no-storage cases, driven by an ~56% reduction in operational expenditure. BESS should be treated as core infrastructure, not ancillary technology. Relying on traditional expansion risks locking the system into higher operational costs, and stressed transmission assets (notably undersized 33 kV lines that need reinforcement). Policymakers and development partners should prioritize storage in planning, create targeted financing instruments, and enable public–private procurement frameworks to accelerate cost-effective solar integration.