Tapioca production consumes large amount of energy to process cassava into tapioca. Most energy used is fossil energy in the form of electricity and diesel oil which availability has declined so that affect the tapioca production process in the very near future. In addition to producing main products, tapioca industry also generates certain amount of by-products such as cassava\'s peel, stockpile and wastewater that potentially be utilized as an energy source. This research aimed to develop a model of a closed system of energy independent production process of tapioca through reusing the by-product as the energy source. Development of a closed system model was based on the mass balance, assessing energy content of by-products, and build a closed system of tapioca production process. This study used secondary data of processing stages and primary data of material balance from a tapioca industry. The results showed that the achievable yield of tapioca was 32%. The tapioca industry with 1,000 ton of cassava per day has the potential energy of 1,407,714,408 kcal per day derived from cassava stockpiles and cassava peels. This potential energy is able to meet the energy requirements of 99,261 kWh per day for the production process. Therefore, the tapioca industry is potentially being an energy independent industry by optimizing the utilization of by-products.