Desalination and sustainability: a triple bottom line study of Australia

Abstract

For many arid countries, desalination is considered as the final possible option to ensure water availability. Although seawater desalination offers the utilisation of almost infinite water resources, the technology is associated with high costs, high energy consumption and thus high carbon emissions when using electricity from fossil sources. In our study, we compare different electricity mixes for seawater desalination in terms of some economic, social and environmental attributes. For this purpose, we developed a comprehensive multi-regional input-output model that we apply in a hybrid life-cycle assessment spanning a period of 29 yr. In our case study, we model desalination plants destined to close the water gap in the Murray-Darling basin, Australia’s major agricultural area. We find that under a 100%-renewable electricity system, desalination consumes 20% less water, emits 90% less greenhouse gases, and generates 14% more employment. However, the positive impacts go hand in hand with 17% higher land use, and a 10% decrease in gross value added, excluding external effects.

Keywords

• LCA
• desalination
• renewable energy
• sustainability
• input-output analysis