Energy sources have become a focus of legal, ethical, social and economic pressures due to increasing environmental problems. Nonrenewable energy sources are being increasingly replaced by other sources that are renewable and less pollutive, with technologies aimed at sustainability. Companies that adopt alternative forms of energy will be able to increase their competitiveness and use wastes to generate energy, which is an ecological and economical efficiency approach. In the interior of the state of Sao Paulo, Brazil, a rural producer of pork crackling and coffee evaluated the entire production cycle of his products and wastes, seeking to achieve energy self sufficiency and identify new possibilities for gains through cost reductions. Biodiesel, soap and detergent are produced with the waste animal fat left from the production of pork crackling. Pig farm wastes become biomass for a biodigester, which produces sufficient biogas to keep the piglets warm, dry the coffee, fry the pork crackling, and generate electricity, among other uses. The biofertilizer produced by the biodigester helps fertilize coffee and corn plantations. The purpose of this article is to demonstrate the ecological and economic feasibility of the project. The research method used here is a case study involving qualitative analyses of environmental and social variables and quantitative analyses of economic variables. It is concluded that the investment made in this project yields excellent returns, with savings of 100% in fuels, 50% in electric energy and 40% in fertilizer, in addition to gains from the products developed with the wastes. (C) 2011 Elsevier Ltd. All rights reserved.