In highly developed countries electricity generation is one of the largest water users. Water is mainly used in the cooling processes of thermal power plants. In as yet less developed countries, electricity requirements are also increasing in step with increasing production and standard of living. Renewable electricity generation is gaining more attention in both highly and less developed economies. However, many types of renewable electricity generation, e.g. wind or solar, are still unreliable due to their dependence on weather conditions. This is why electricity generation by thermal power plants will remain a substantial component of the overall energy system for the next decades. An approach is applied here for analysing links between water availability and water temperature, air temperature and electricity generation by power plants. A highly disaggregated level is used combining a power plant model and hydrological models. It is applied to analyse effects of climate change on 17 nuclear power plants in Germany. Although even under baseline conditions reduced electricity generation can be observed, any further increase in air temperatures reduces electricity output of almost all nuclear power plants. The different technological and environmental conditions of each plant site mean that specific models are necessary for the simulations. (C) 2014 Elsevier Ltd. All rights reserved.