Exploring options for energy recovery from wastewater: Evaluation of hydropower potential in a sustainability framework

Abstract

[EN] Current energy demand for wastewater treatment is very high and expected to increase in the next decade. As climate change poses a challenge too, renewable energy options for this industry are needed. Studies for hy-dropower assessment addressed to governance stakeholders have shown that some mechanical energy might be recovered from wastewater. However, none of them applied a sustainability approach. Neither the decision -making level was considered. The objective of this work is to present a methodology, developed and applied to a case study, with a novel approach, including all these considerations. After analyzing the context in the region of study, the proposed methodology includes all three dimensions of sustainability: economic, environ-mental, and social. Firstly, the methodology was applied to a group of 186 plants, selected according to their management model. Based on technical feasibility, 34 potential sites were identified. Secondly, to obtain the sustainability perspective, a survey of suitable criteria was conducted. Then, a multi-criteria method, aligned with existing governance guidelines, was proposed and applied. The results show that, in a sustainability framework, hydropower might be an interesting option to consider for the decarbonization of wastewater sys-tems. Based on this study, stakeholders could directly design decision-making methodologies adapted to their context.