From technical viability to bankability: An integrated assessment of gigawatt-scale solar PV under compound uncertainty, evidence from Nigeria

Utility-scale solar PV deployment in emerging electricity markets turns on whether policy and institutional arrangements make projects financeable, not on irradiation and hardware prices alone. This paper develops an integrated assessment framework linking four dimensions usually treated separately, namely technical performance, grid deliverability, financial viability, and environmental, social, and governance (ESG). The framework is applied to Abuja Solar One, a proposed 1 GW PV project in Nigeria, using feasibility-study data, comparative benchmarks, and a new compound scenario model. The case shows strong technical fundamentals, including a reported post-tax levelised cost of electricity of USD 0.0663/kWh from the feasibility study. Technical viability alone does not ensure bankability. A compound uncertainty analysis spanning 81 deterministic combinations of generation, curtailment, tariff, and CAPEX, to which no probabilities are assigned, shows that 6 combinations return an unlevered project IRR at or above an illustrative 15% cut-off, 54 fall between 12% and 15%, and 21 fall below 12%. Curtailment is the dominant single downside driver, while tariff compression and CAPEX escalation add to the downside additively, not through interaction, since the two-way curtailment and tariff interaction term is negligible. The threshold structure survives a complete change of the national fiscal incentive regime and the introduction of debt, although leverage relocates the binding constraint from the return test to debt service coverage. The findings suggest that in high-risk electricity markets the central assessment question is not whether gigawatt-scale solar can be built, but under what institutional conditions it can attract capital and remain investable.