The increasing global demand for clean water and sustainable energy solutions has driven the exploration of hybrid renewable energy systems for desalination applications. This study investigates the optimal sizing of a stand-alone hybrid energy system comprising photovoltaic (PV) panels, fuel cells (FC), and battery storage (BS) to power a seawater desalination (SD) plant and meet the electrical load of a tourist resort in Ras Al-Hekma City, Egypt. The resort's total electrical demand of 3.5 MVA includes a reverse osmosis (RO) desalination plant, lighting, air conditioning, and a wastewater treatment facility. Three system configurations; PV/BS, PV/FC, and PV/FC/BS; were analyzed to determine the most cost-effective and reliable solution. The performance of each system was evaluated based on energy production, storage requirements, and economic metrics such as the cost of energy (COE) and net present cost (NPC). Results indicate that the PV/FC/BS hybrid system offers a balanced solution with a COE of 0.081 $/kWh, combining the reliability of fuel cells with the sustainability of solar energy and battery storage. This research highlights the potential of hybrid renewable energy systems to address water scarcity and energy challenges in remote coastal regions while contributing to Egypt's renewable energy goals.