Impacts of recent drought and warm years on water resources and electricity supply worldwide

Recent droughts and heatwaves showed the vulnerability of the electricity sector to surface water constraints with reduced potentials for thermoelectric power and hydropower generation in different regions. Here we use a global hydrological-electricity modelling framework to quantify the impacts of recent drought and warm years on hydropower and thermoelectric power usable capacity worldwide. Our coupled modelling framework consists of a hydrological model, stream temperature model, hydropower and thermoelectric power models, and was applied with data of a large selection of hydropower and thermoelectric power plants worldwide. Our results show that hydropower utilisation rates were on average reduced by 5.2% and thermoelectric power by 3.8% during the drought years compared to the long-term average for 1981-2010. Statistically significant (p < 0.01) impacts on both hydropower and thermoelectric power usable capacity were found during major drought years, e.g. 2003 in Europe (-6.6% in hydropower and -4.7% in thermoelectric power) and 2007 in Eastern North America (-6.1% in hydropower and -9.0% in thermoelectric power). Our hydrological-electricity modelling framework has potential for studying the linkages between water and electricity supply under climate variability and change, contributing to the quantification of the 'water-energy nexus'.