Hybrid Renewable energy system water desalination systems is gaining popularity due to increased demand for water and energy, as well as a desire to reduce carbon emission. The main aime of this paper is to design a renewable energy system capable of meeting the electrical load requirement of a small-scale reverse osmosis desalination plant (65m3 /d), in NRC Noubarya Farm, Egypt as well as to determine the ideal sizing and assess the techno-economic and environmental feasibility of various off-grid power system configurations. Also designs a new hybrid renewable energy system (HRES) for this RO plant by conducting simulations using the HOMER (Hybrid Optimization of Multiple Energy Resources) software. three power systems configures investigated and analyzed based on economic and environmental bases: (PV/ Wind turbine (WT)/DG), (PV/ WT/DG/Battery). The comparisons result of hybrid configuration systems shows the optimal hybrid power system configuration is PV/WT/DG/Battery, which has the lowest COE of 0.274$/kWh, Renewable Fraction (RF) as 87.1%, Net present cost(NPC) is about 66,081.46 $ and CO2 emissions as 417,752 kg/year