This paper presents a biophysical understanding of the MSW-to-energy facility located at the Sao Joao landfill in Sao Paulo using Emergy synthesis. Accounting for the material inputs and the biogas accumulation Emergy-based indices are calculated to evaluate the environmental load and sustainability level of the concerned biogas project. The study was conducted by combining the analysis of transformities, Emergy indicators and the net Emergy yield ratio to establish long-term sustainability and measure global environmental stress. The implementation of a project for environmental compensation in fulfilment of state’s requirements was also assessed. The findings reveal that the Emergy investment to the use of biogas is quite low and, therefore, advantageous. Transformities show that the global productivity of the MSW-to-energy plants can compete with traditional plants. The conclusions justify the effort invested in developing MSW-to-energy plants and are relevant for policy makers in a highly sensitive sector to accomplish sustainability goals.