doi:10.3390/batteries11020070engDufo-López, RodolfoLujano-Rojas, Juan M.Optimization of Size and Operation of Stand-Alone Renewable-Based Systems with Diesel and Hybrid Pumped Hydro Storage–Battery Storage Considering UncertaintiesART-2025-143235Currently, the electrical supply in stand-alone systems is usually composed of renewable sources with fossil-fuel generators and battery storage. This study shows a novel model for the metaheuristic–stochastic optimization (minimization of the net present cost, and NPC) of sizing and energy management for stand-alone photovoltaic (PV)–wind–diesel systems with hybrid pumped hydro storage (PHS)–battery storage systems. The model is implemented in C++ programming language. To optimize operations—thus reducing PHS losses and increasing battery lifetimes—optimal energy management can optimize the power limits of using the PHS or battery to supply or store energy. The probabilistic approach considers the variability of wind speed, irradiation, temperature, load, and diesel fuel price inflation. The variable efficiencies of the components and losses and advanced models for battery degradation are considered. This methodology was applied to Graciosa Island (Portugal), showing that, compared with the current system, the optimal system (with a much higher renewable power and a hybrid PHS–battery storage) can reduce the NPC by half, reduce life cycle emissions to 14%, expand renewable penetration to 96%, and reduce the reserve capacity shortage to zero.2025http://zaguan.unizar.es/record/15167510.3390/batteries11020070http://zaguan.unizar.es/record/151675oai:zaguan.unizar.es:151675info:eu-repo/grantAgreement/ES/AEI/PID2021-123172OB-I00info:eu-repo/grantAgreement/EUR/AEI/TED2021-129801B-I00info:eu-repo/grantAgreement/EUR/ISCII-ERDF/A way to make EuropeBatteries 11, 2 (2025), 70 [32 pp.]byhttps://creativecommons.org/licenses/by/4.0/deed.esinfo:eu-repo/semantics/openAccess