Energy use and decarbonisation of the water sector: a comprehensive review of issues, approaches, and technological options
Andrea G. Capodaglio
Abstract
Water and wastewater infrastructure is a major energy consumer and an important source of global greenhouse gas emissions: on average, 10.6 kg CO2/m3 of water is consumed. The European Environment Agency in 2019 estimated these emissions from wastewater treatment operations in Europe alone at over 25 MtCO2eq. Increased demand (in terms of volumes and quality) in the water sector raises expectations of future increases if appropriate measures will not be undertaken. Many water companies and utilities associations have been or are developing plans to achieve net zero on an industry-wide basis by 2050, and some have cut emissions by 50% in the last ten years. About half of energy-related emissions from water sector facilities could be significantly abated by applying existing technologies, and close to 95% of this objective could be achieved at zero or negative cost with proper innovation strategies. This paper examines and discusses issues, possibilities, and technologies that could be considered in planning the reduction of water and WW-related GHG emissions with a holistic view of the entire water sector, based on a recent literature review.HighlightsThe water sector’s GHG emissions amount to 2–4% of global emissions, bound to increase in the coming yearsDecarbonisation can be strategically addressed according to key system components: demand, technology, and removal/reductionAchievement of net zero in the water sector will need a holistic approach encompassing substantial paradigmatic changes