Reliance on a single renewable energy source has its limitations, which are effectively addressed by the hybrid solar-biomass renewable energy system. Research and development of internal combustion engines driven by a syngas-biogas-hydrogen blend is necessary in this energy system. The process of converting solid waste into RDF (Refuse-Derived Fuel) and gasifying it to create syngas allows biomass to be stored for future use, improving the stability of the hybrid renewable energy system. The simulation’s findings indicate that the most effective conditions for gasifying biomass are an excess air ratio of between 0.2 and 0.4 and a reduction zone temperature between 900 and 1000 K. Because syngas has a low air-to-fuel ratio, twining injector systems are an appropriate way to provide a flexible fuel mixture of syngas, biogas, and hydrogen to spark ignition engines that are part of hybrid renewable energy systems. Adjusting the opening angle of the two injectors effectively enables the supply of fuel mixtures with significantly varied air-to-fuel ratios among its components.