Coordination capacity and renewable energy policy implementation: Solar power adoption across Nigerian states

Motivation Why do subnational governments operating under the same federal framework achieve different renewable energy implementation outcomes? In developed economies, explanations point to fiscal resources and bureaucratic quality. In frontier economies, these are either impossible to measure credibly or too fragmented for reliable comparison, leaving standard frameworks with limited purchase where decentralization is expanding. Purpose The article puts forward coordination capacity, specifies how it operates and how it is built or fails within weak‐capacity subnational energy governance to explain the variation. Approach and Methods The study uses process tracing and within‐case comparison across Nigeria's 36 states following the 2023 Electricity Act, drawing on interviews with state and federal officials, developers, and donors, alongside cross‐sectional analysis of off‐grid solar deployment and a mapping of subnational climate governance. Because coordination capacity is observable through institutional practices rather than quantitative indicators, the qualitative design isolates its mechanisms where standard measures fail. Findings States with comparable revenues diverge depending on whether they have the enabling arrangements for coordination, sustain the practices that activate them, and generate the outcomes that follow. The article distinguishes three layers: a focal agency with delegated authority and institutional memory; procedural follow‐through and horizontal coordination; and predictability, reduced transaction costs, and project continuity. Niger State's high deployment despite low revenue, as compared to Akwa Ibom's near‐zero deployment despite fiscal advantage, anchors the argument. Policy Implications Coordination capacity is necessary for converting formal decentralization, donor interest, or regulatory openings into delivered projects, although it does not displace fiscal resources, politics, or market structure as background determinants. Because it is unevenly distributed and self‐reinforcing, decentralization without institutional investment reproduces spatial inequality, concentrating finance in jurisdictions already legible to external partners.