Design and Validation of a Multi-Tier Hybrid Renewable Energy System for Off-Grid Communities: A Simulation-Based Approach to Energy Resilience and Economic Viability

The deployment of renewable energy systems in isolated regions presents unique challenges related to resource intermittency, storage requirements, and economic feasibility. This study presents a comprehensive framework for designing and validating a hybrid renewable energy system tailored for off-grid communities, combining photovoltaic arrays, wind turbines, battery storage, and hydrogen-based long-term energy storage with diesel backup. Unlike conventional optimization-only approaches, the proposed methodology integrates analytical sizing with dynamic simulation and multi-scenario validation to ensure system resilience under varying climatic conditions. The framework is applied to a representative case study in Salah Bey, Algeria, where a 12,090 MWh/year load demand is to be met. Through MATLAB-based hourly simulations and independent validation using HOMER Pro, the system demonstrates reliable performance under normal, degraded, and stochastic climatic scenarios, achieving 100% renewable penetration under standard conditions and maintaining supply continuity even under extreme resource reduction (99.7% load coverage). Techno-economic analysis reveals a levelized cost of energy of 41.29 DA/kWh, an internal rate of return of 15.35%, and annual CO₂ emission reductions exceeding 8,000 tonnes compared to diesel-only alternatives. The close agreement between MATLAB and HOMER Pro results (deviations below 7% for key parameters) validates the proposed sizing methodology. This work provides a practical, replicable design and validation framework applicable to diverse off-grid electrification contexts, demonstrating that hybrid renewable systems can achieve both technical reliability and economic competitiveness while substantially reducing environmental impact.