This paper presents the voyage of an innovative design and development and performance study of the multi-condition acceptability and flexible operation of a tar-free municipal solid waste (MSW)–refuse derived fuel gasifier. The innovation of the technology and its development are highly emphasised for converting waste into energy through gasification. The designed and fabricated gasifier (100 kg/h capacity) is a downdraft gasifier that is square in shape and operates slightly above atmospheric pressure to generate tar-free producer gas. The design operates with pellets and fluffy MSW. The generated producer gas was tested for both thermal applications. This designed gasifier can be scaled up and implemented to suit the requirements of industrial energy demand, which has wide-ranging applications. For optimum performance, a 25 kg amount of char is needed to gasify MSW completely. The energy output from the mass and energy balance is 92.5% optimal for effective gas generation. Energy generation from the designed gasifier and process optimisation for thermal energy from gas with enhanced efficiency abets in drastically reducing the cost of factory’s energy consumption. This also helps achieve reduced environmental emissions with good returns on investments.