With the demand for Biofuels growing – in Brazil and abroad – and with worldwide efforts to reduce greenhouse gas (GHG) emissions, Brazil would have much to gain, from an environmental and economic point of view, from increasing the efficiency and offer of biofuels. The advent of biofuels produced in algae farms enabled a symbiotic relationship with ethanol plants. Such algae feeds off, among other things, Carbon Dioxide, and the abundant biomass burned in ethanol plants boilers, along with Brazil s privileged solar incidence, and this regime permits such farms to convert GHG to biofuel. The objective of this study was to investigate an ethanol plant as a productive system to understand how the addition of an algae farm could change the status quo of energy efficiency and emission of pollutant gases. The system analyzed includes the sugarcane sowing, the plantation handling, the harvesting, the industrial activities, and the Ethanol distribution. The goal, from this analysis and using primary data from a company that installs algae farms, is to estimate the increase of biofuel generated by algae and decrease GHG emissions in the production process. The results obtained in Plant Studied show that an algae farm in its industrial grounds would better its energy efficiency in almost threefold, while generating four times less atmospheric pollution in their production chain. If the plant chose to produce exclusively Biodiesel, production of B100 Biodiesel would be enough for the industry s diesel needs for 19 years, with a 78.4 percent cleaner fuel in terms of GHG emissions. Approximations show that if all the sugar cane fields implant algae farms in Brazil, the Biodiesel generated in this process would be equivalent to almost 70 percent of the Brazilian production of diesel from 2012.