To demonstrate what is required to optimise the sizing of solar/BESS installations, this paper presents a numerical model that factors solar and power grid importation using BESS, to reduce grid power charges. . To address the inherent challenges of intermittent renewable energy generation, this paper proposes a comprehensive energy optimization strategy that integrates coordinated wind–solar power dispatch with strategic battery storage capacity allocation. Through the development of a linear programming. . Photovoltaic (PV) and wind power generation are very promising renewable energy sources, reasonable capacity allocation of PV–wind complementary energy storage (ES) power generation system can improve the economy and reliability of system operation. In this paper, the goal is to ensure the power. . Existing solar/battery energy storage systems (BESS) have established sizing practices that obtain data from; peak demand records provided by energy retail companies, software modelling that applies proven renewable asset generation profiles, and average base load power usage recorded from energy. .