The objective of this research is to evaluate the optimum combination of stand-alone hybrid renewable energy systems to match the load demand in a sustainable and cost-effective way. (HOMER) simulation program has been analyzed for three Egyptian key highways. The configuration of the systems has been compared and analyzed based on the performance of their technical parameters, costs, and the electrical power generation of each source. The results have estimated that the off-grid solar-wind-diesel-battery configuration is the most economical for all the sites among other system configurations, with the least and most reliable and resilient solution in terms of net present cost and cost of energy. The study investigates that the average cost of electricity for three sites is 0.322 $/kWh, and the average net present cost of electricity for those sites is 487539 $/Yr, which is not only economical compared to a stand-alone diesel system where the obtained average cost of electricity is 0.727 $ and the net present cost is 1.10 $, but also reasonable carbon dioxide emissions than any used renewable energy systems since they produce 10,663 kg/yr at their optimum, whereas the stand-alone diesel system produces 146978 kg/yr