The abundance of waste resources can be utilized to generate sustainable and clean energy. Microwave-assisted pyrolysis is an effective technique for converting various materials, including wood chips, plastic, food, and general hospital waste, into by-products with significant energy recovery potential. The yield and quality of these by-products were studied under optimized microwave pyrolysis conditions. Polyethylene plastic and general hospital waste produced high biochar heating values (31.6–37.9 MJ/kg), exhibiting high carbon content, low oxygen concentration, high aromatic compounds, and lower extractive content. The pyrolysis of food waste, based on the operating conditions and feedstock properties, resulted in high bio-oil (35 %) and biogas (57 %) generation. Energy balance analysis indicated that wood chips biomass (16.7 %) and hospital waste (14.8 %) achieved the highest energy efficiency.