Technical Due Diligence Assessment of Solar Mini-Grid Assets for Acquisition Financing in Northern Nigeria

This study develops and applies a technical due diligence framework for the assessment of solar mini-grid assets being considered for acquisition financing in Northern Nigeria, addressing a gap in structured evaluation methodology for mini-grid investment in the Nigerian off-grid energy sector. The growing pipeline of solar mini-grid projects developed by independent power producers under the Rural Electrification Agency's framework is attracting debt and equity investors who require rigorous technical assessment to underpin their investment decisions. The framework is developed through a synthesis of international best practices from the IFC Mini-Grid Investor Toolkit, ESMAP technical assessment guidelines, and interviews with 12 mini-grid investors and developers active in Nigeria. The framework encompasses nine assessment domains: site and resource data quality, system design adequacy, equipment specification and origin, installation quality, protection and safety standards, metering and revenue management systems, operations and maintenance capability, historical performance data, and contractual and regulatory compliance. The framework is applied to four operational mini-grids in Sokoto, Kano, Gombe, and Borno States, each with capacities between 50kW and 200kW. Assessment findings across the four sites reveal that metering accuracy, protection system documentation, and operations capability are the most frequently deficient domains. Common deficiencies include absent or incomplete commissioning records, undersized charge controllers relative to actual PV array capacity, and the absence of maintenance service agreements. The framework enables consistent, bankable technical risk scoring for mini-grid investment decisions. Keywords: technical due diligence, mini-grid, solar energy, investment assessment, Northern Nigeria.