Theoretical Foundations and Experimental Validation of a Multi-Objective Optimisation Framework for Hybrid Renewable Microgrid Design in Sub-Saharan African Contexts

This research develops a theoretically rigorous and experimentally validated multi-objective optimisation framework specifically designed for hybrid renewable energy microgrid design in Sub-Saharan African contexts, with application sites in North West and North East Nigeria, making original contributions to both the optimisation theory and the practical microgrid design science for low-income energy access environments. Existing microgrid design optimisation tools, including HOMER and iHOGA, employ cost minimisation as their primary objective and use probabilistic load and resource data that do not adequately reflect the non-stationary, behavioural, and institutional realities of rural Sub-Saharan African microgrids. The proposed framework introduces three theoretical advances: a novel multi-objective problem formulation incorporating levelised cost of energy, energy reliability index, social equity metrics, and environmental impact simultaneously; a context-adaptive uncertainty quantification method that propagates multi-dimensional uncertainty in load behaviour, solar resource, component reliability, and tariff affordability through the design optimisation; and a Pareto front navigation method that enables participatory decision-making among community stakeholders with diverse preferences. The framework is implemented using a hybrid of non-dominated sorting genetic algorithm II and local gradient search. Experimental validation is conducted on three microgrid systems in Zamfara, Yobe, and Gombe States, with actual system performance compared against design predictions over 18 months of operation. The framework achieves prediction accuracy within 6 percent for energy cost and 3 percent for reliability metrics, demonstrating superior predictive validity over HOMER under the studied conditions. Keywords: multi-objective optimisation, microgrid design, renewable energy, Sub-Saharan Africa, Nigeria.