Integrated sustainability assessment framework for geothermal energy technologies: A literature review and a new proposal of sustainability indicators for Mexico

Mexico's energy agenda has the commitment to achieve a share of 35% of renewable energy in the energy portfolio by 2025. Geothermal energy is a source that may contribute to this goal due to the enormous potential, and because it constitutes a viable option for energy diversification and decarbonisation of the electricity sector. However, it is recognised that the geothermal power plants and the direct use technologies still produce some negative sustainability impacts that need to be reduced. With these purposes, an integrated sustainability assessment framework to evaluate such geothermal technologies was developed with the following goals: (i) to obtain an updated systematic literature review on sustainability assessment frameworks, and life-cycle assessment studies to quantify sustainability impacts; (ii) to generate a new set of geothermal sustainability indicators for their future application in projects of electricity generation and direct uses of Mexico; and (iii) to propose sustainable strategies to support the deployment of new geothermal projects for Mexico. As key findings of this investigation, a new integrated framework to assess the sustainability of geothermal technologies, and a new set of 36 sustainability indicators were obtained. These sustainability indicators were selected through a participatory stakeholder engagement conducted by 136 respondents from the society, government, industry and academia. These indicators were ranked and prioritised using multi-criteria decision analysis techniques by additionally considering the main physicochemical and geological features of Mexico geothermal systems, and the production technologies currently installed. With this methodology, key sustainability challenges for the geothermal industry of Mexico can be tackled.