Driven by global hydrocarbon depletion and escalating environmental concerns, this research addresses the critical need for sustainable energy transitions in Algeria to meet 2030 renewable energy targets. This study investigates the techno-economic feasibility and environmental sustainability of a grid-connected Hybrid Renewable Energy System (HRES) optimized via HOMER Pro to satisfy a 1 MWh daily load in the Saharan climate of Kabertane. The primary objective is to design a synergistic configuration of Photovoltaic (PV) arrays, Wind Turbines (WTs), and Fuel Cell (FC) that mitigates renewable intermittency while reducing fossil fuel dependency. Optimization results identify the PV/WT/FC grid-connected architecture as the optimal topology, achieving a 92.2% renewable energy fraction and a minimized Cost of Energy (COE) of 0.127 $/kWh. Financial indicators demonstrate robust viability, featuring a Net Present Cost (NPC) of $1.42 million, an Internal Rate of Return (IRR) of 42.4%, and a rapid payback period of 2.36 years. Environmentally, the system facilitates an 83% reduction in Carbon Dioxide (CO2) emissions compared to traditional grid reliance. Furthermore, sensitivity analysis confirms the configuration's resilience against resource variability and capital expenditure fluctuations, providing a scalable framework for enhancing energy sustainability in desert environments.