Industrial ethanol production is a biochemical process that converts carbohydrate-rich or cellulosic biomass into alcohol through fermentation, followed by purification and dehydration. The choice of feedstock, process technology, scale of operation, and integration with agricultural systems determine the efficiency, cost-effectiveness, and sustainability of ethanol production. In the context of renewable energy management in agriculture, ethanol production provides value addition to crops, crop residues, and agro-industrial by-products while contributing to energy security and rural income generation. Ethanol can be produced from three broad categories of feedstocks: sugar-based, starch-based, and lignocellulosic materials. Sugar-based feedstocks such as sugarcane juice, sugarcane molasses, sugar beet, and sweet sorghum contain readily fermentable sugars like sucrose, glucose, and fructose. In India, molasses derived from sugar mills is the most common feedstock. The production process begins with clarification and dilution of the feedstock to achieve optimal sugar concentration. Yeast, commonly Saccharomyces cerevisiae, is added for fermentation. During fermentation, sugars are converted into ethanol and carbon dioxide under anaerobic conditions. The fermented mash, typically containing 7–12 percent ethanol, is then subjected to distillation to separate ethanol from water and other components. For fuel-grade ethanol, dehydration is carried out using molecular sieves or azeotropic distillation to achieve a purity of 99.5 percent or higher. When sugarcane juice or syrup is directly used, the process is similar but integrated within sugar mills, allowing flexibility between sugar and ethanol production depending on market and policy signals. This integrated approach improves resource efficiency, ensures better utilization of cane, and stabilizes farmer incomes by reducing dependence on sugar price fluctuations. In agricultural management terms, such integration supports diversification and risk mitigation for cane growers. Starch-based feedstocks include maize, broken rice, wheat, barley, and other cereals. These materials contain complex carbohydrates in the form of starch, which must first be converted into fermentable sugars. The industrial process involves milling to produce flour or slurry, followed by liquefaction and saccharification. During liquefaction, enzymes such as alpha-amylase break down starch into shorter chains called dextrins. In the saccharification stage, glucoamylase converts dextrins into glucose. The glucose-rich solution is then fermented using yeast, similar to sugar-based processes. After fermentation, distillation and dehydration steps yield fuel-grade