Freshwater footprint of fossil fuel production and thermal electricity generation and water stresses across the National Electricity Market (NEM) region of Australia

Abstract

Fossil fuel powered energy generation is highly water intensive and competes with other end users for water. An assessment of the water footprint of energy systems is thus an important consideration for planning decisions that balance demand with reliable supply of both energy and water, cost-effective technologies, and the imperatives of climate change. A comprehensive study is lacking in the Australian context where fossil fuels currently dominate energy supply and freshwater can be a scarce resource, though water-energy footprint studies are available elsewhere. Therefore, for the first time, this study has attempted to track the freshwater footprint of fossil fuel production and subsequent electricity generation in the National Electricity Market (NEM) region of Australia. Water withdrawal and consumption intensity factors, mostly Australian values, were used to calculate the water withdrawal and consumption volumes at spatial scales of thermoelectric power plants, catchments and states within the NEM. The vulnerability of energy production in the region to water stress on a catchment level was also analysed, though limited by available data. The results showed that coal accounted for more than 85% of the total freshwater withdrawal and consumption associated with fossil fuel energy production. Thermoelectric power generation dominated water withdrawal volumes, while water consumption was dominated by primary fuel production. A considerable amount of consumed water (256 GL/year) was found to be exported as virtual water, mainly associated with coal. It was also revealed that at least six of the twenty seven catchments in the NEM region were experiencing medium to high water stress, with competition between multiple water users for available freshwater, particularly during dry periods. This study provides insights on commonly overlooked aspects of ‘water for energy’ in Australia that provides a basis for ongoing assessments and planning.