<p>Optimizing the size and operation of islanded microgrids becomes essential due to the need for cost-effective and reliable energy solutions. This study focuses on the optimal sizing and energy management of an islanded AC/DC microgrid to minimize the levelized cost of energy. The hybrid islanded microgrid is planned to operate optimally throughout the project’s life cycle. The proposed framework integrates various distributed energy resources, including wind turbines, photovoltaic systems, electrical energy storage systems, and diesel generators to provide continuous and stable power required by local AC and DC loads. In the hybrid microgrid, local buildings loads operate on AC power while the electric vehicle charge station functions with DC power. Additionally, the annual growth rate of local energy demand is incorporated into the optimization framework to achieve an optimal architecture of the microgrid that can remain adaptive to evolving consumption patterns over time. The proposed method adopts a deterministic exhaustive-search optimization framework in which all feasible combinations of the decision variables are systematically evaluated over the project lifetime. Through numerical evaluations, the proposed sizing and energy management method demonstrates its effectiveness in enhancing economic feasibility and resilience in off-grid environments over the project life cycle.</p>