Potential of electricity generation by organic wastes in Latin America: a techno-economic-environmental analysis

Waste-to-energy technologies from anaerobic digestion (WtE-DA) are successfully used in European countries for electricity generation. In Mexico, the application of these processes is limited due to their design and operation complexity, high required investment, high operations and maintenance costs, and low government support, which hinders their economic competitiveness. This work conducted a study to determine the best conditions of electricity generation through WtE-DA processes to be competitive compared with the conventional process. An industrial-scale process was designed regarding the co-digestion of fruit and vegetable waste from a food supply center with slaughterhouse waste from the Monterrey Metropolitan Area in Mexico. Analysis scenarios were strategically proposed considering different sizes of the WtE-DA plant, transport distance from the source of waste to the process, and the degree of government participation through economic subsidies granted to clean energy production. The environmental performance of the plant was evaluated via the climate change indicator (CCI) following a life cycle analysis approach, and the net present value (NPV) was used as an economic criterion. The results show that the CCI has a high sensitivity to the waste transport distance, having a maximum of 130 km to ensure environmental success. The sensitivity analysis performed on the management capacity and NPV indicates that plants smaller than 72,000 t year −1 are economically unviable and require governmental financial support like that granted in European countries. This work provides reliable operating, eco-efficiency criteria, and subsidy schemes to support decision-making for proper investment in bioenergy projects.