Analysis of performance losses of thermal power plants in Germany – A System Dynamics model approach using data from regional climate modelling

The majority of thermal power plants of more than 300 MW use river water for cooling purposes. Increasing water and air temperatures due to climate change can significantly impact the efficiency and the power production of these power plants. In this paper we analyse these impacts by modelling selected German thermal power plant units and their respective cooling systems through dynamic simulation taking into account legal thresholds for heat discharges to river water together with climate data projections (SRES scenarios A1B, A2, and B1). Possible output and efficiency reductions in the future (2011–2040 and 2041–2070) are quantified for thermal power plants with once-through (OTC) and closed-circuit (CCC) cooling systems under current legislative framework. The model validation showed that the chosen System Dynamics approach is appropriate to analyse impacts of climate change on thermal power units. The model results indicate lowest impacts for units with CCC systems: The mean trend for CCC for the A1B scenario (2011–2070) is expected to be −0.10 MW/a and −0.33 MW/a for an OTC system. On a daily basis, the power output of all considered OTC units is reduced down to 66.4% of the nominal capacity, for a single unit even down to 32%.