Using OnSSET to develop least cost energy technology pathways for South-East Nigeria (2025 – 2060)

This study employs the Open Source Spatial Electrification Tool (OnSSET) to develop least-cost, spatially optimized energy technology pathways for Southeast Nigeria from 2025 to 2060. The research addresses the region's critical energy challenges, including a 74.6% electrification rate, heavy reliance on an unreliable national grid, and a 41.7% electricity supply-demand gap. The primary objective is to identify pathways that achieve universal energy access and net-zero carbon emissions by 2060, aligning with the 2023 Nigeria Electricity Act and the Nigeria Energy Transition Plan (ETP). Three core scenarios were modelled: Business-as-Usual (BAU), Least-Cost Technology (LCT), and a Green Transition. The analysis reveals that the BAU scenario requires an investment of approximately $8.43 billion and results in emissions of 2,198 tCO2 by 2060. In contrast, the Green Transition pathway emerges as the optimal strategy, slashing emissions by 80% to 436 tCO2 while maintaining a virtually identical investment cost (approx. $8.44 billion). A critical finding is that a hybrid approach which combines a modernized, decarbonized grid with strategically deployed decentralized solar system, proves more cost-effective than an over-reliance on mini-grids. The study concludes that deep decarbonization is achievable without significant additional system-wide cost. It recommends policy actions including the formalization of geospatial planning, prioritized grid modernization, targeted support for decentralized solar, and the development of a granular, phased implementation strategy to guide Southeast Nigeria towards a sustainable energy future.