Multiobjective optimization-based design and dispatch of islanded, hybrid microgrids for remote, off-grid communities in sub-Saharan Africa
This addresses the problem of affordable, sustainable, and reliable electricity access for off-grid communities in sub-Saharan Africa, with incremental improvements in microgrid optimization.
The paper tackled the design and dispatch of islanded hybrid microgrids for remote communities by developing a multiobjective optimization framework, showing that a solar PV-wind system with lithium-ion battery storage and diesel backup outperforms alternatives and reduces upfront capital needs.
A multiobjective, multiperiod global optimization framework is developed for the design, sizing, and dispatch of an islanded hybrid microgrid. System sizing is optimized over a one-year horizon and operational dispatch over a representative day, both at hourly resolution. The formulation minimizes lifecycle levelized cost of energy, emissions, lost load, and dumped energy, while maximizing renewable penetration. The approach identifies optimal capacities of renewable generation, storage, and backup generation that balance affordability, sustainability, reliability, and efficiency. Among the methods evaluated, particle swarm optimization is well suited for the nonconvex, multiobjective sizing problem. Results show that a solar PV-wind microgrid with lithium-ion battery storage and diesel backup consistently outperforms alternatives. Cost considerations dominate allocation among renewable sources, while sizing of renewables and storage is influenced by standby generation ratings due to reliability constraints. Pareto-optimal solutions reveal key tradeoffs among economic, environmental, and reliability objectives, showing that cost-only optimization can yield poorer emissions, reliability, and curtailment outcomes. Sensitivity analyses highlight the impact of fuel prices and storage costs on optimal design. Accurate sizing reduces unnecessary oversizing used to ensure reliability in off-grid systems, lowering upfront capital needs and improving affordability of clean electricity access. The dispatch model produces day-ahead schedules generally robust to short-term uncertainty, though disturbances increase reliance on fossil backup. Effective dispatch of batteries and backup generators is critical. The study also reviews microgrid design tools and methods, and addresses applications in sub-Saharan Africa.