The changing virtual water trade network of the European electric grid

In the generation of electricity, water is consumed through cooling of thermoelectric power plants and evaporation behind hydroelectric dams before flowing throughout the physical electric grid as an embedded resource. In the European electric grid, there are significant amounts of electricity resources traded between countries to balance power demands, creating a virtual water trade network. To understand the scale and burden shift of this virtual water trade, we create a resource accounting model that couples embedded water resources with international electricity trade throughout Europe at a sub-annual time-scale. Using data from the European Network of Transmission System Operators for Electricity, we identify an increase of virtual water trade from 43 million m3 to 49 million m3 between 2010 and 2017, with significant seasonal variation. We further contextualize these temporal variations of virtual water trade through an analysis of changing electricity policies in three countries (Italy, Great Britain, and Germany) and their subsequent effects on virtual water trade. In developing this virtual water network, we identify significant data gaps that lead to uncertainty and create challenges for decision-making, suggesting the need for a comprehensive data collection plan on the impact of energy on water resources across Europe.