Sustainability assessment of energy systems: integrating environmental, economic and social aspects

Sustainable development of energy systems requires consideration of all three sustainability dimensions: environmental, economic and social. Current work presents a new decision-support framework for facilitating this. Taking a life cycle approach, the framework integrates the three sustainability dimensions to enable assessments at both technology and systems levels. The framework comprises scenario analysis, life cycle assessment, life cycle costing, social sustainability assessment and multi-criteria decision analysis, which are used to assess and identify the most sustainable energy options. The application of the framework is illustrated on the example of future electricity supply in Mexico. Eleven scenarios up to 2050 have been developed considering different technologies, electricity mixes and climate change targets. The results show that, based on the 17 sustainability criteria used in this work, the business-as-usual scenario, mostly based on fossil fuels, is unsustainable regardless of the preferences for different sustainability criteria. This is mainly due to the high costs and environmental impacts associated with fossil fuels. Overall, the most sustainable scenarios are those with higher penetration of renewables (wind, solar, hydro, geothermal and biomass) and nuclear power. These electricity pathways would enable meeting the national greenhouse gas emission targets by 2050 in a more sustainable way than envisaged by the current policy. However, some trade-offs among the sustainability criteria are needed, particularly with respect to the social impacts. These trade-offs can be explored easily within the decision-support framework to reveal how different stakeholder preferences affect the outcomes of sustainability assessment, thus contributing to more informed decision and policy making.