Abstract ID: 068
Weather regimes: A window of sub-seasonal forecast opportunity for periods of low renewable electricity generation in Germany?
Lead Author: Fabian Mockert
Institute of Meteorology and Climate Research (IMK-TRO), Department Troposphere Research, Karlsruhe Institute of Technology (KIT), Germany
Keywords: Dunkelflauten, weather regimes, renewable energies, energy demand, predictability
Abstract: Weather regimes are quasi-stationary, recurrent, and persistent states of the large-scale extratropical circulation which explain the bulk of multi-day weather variability in midlatitude regions. Due to their modulation of surface weather on continent-size regions, regime forecasts have become a useful tool for sub-seasonal forecasts in the energy sector. However, the link between weather regimes and periods of extremely low renewable power output, which particularly stress the energy system, remains unclear. Here, we explore the meteorological conditions during periods of low wind and solar power output in Germany, so-called ‘Dunkelflauten’.
We find that in Germany, Dunkelflauten mainly occur in winter when the solar power output is anyway low and when the wind power output drops for several consecutive days. A high-pressure system over Germany, associated with the European Blocking regime, is responsible for most of the Dunkelflauten. Dunkelflauten during the Greenland Blocking regime are associated with colder temperatures than usual, causing higher electricity demand and presenting a particular challenge as space heating demand electrifies in future. Furthermore, we show that Dunkelflauten occur predominantly when a weather regime is well-established and persists longer than usual.
Our study provides novel insight into the occurrence and meteorological characteristics of Dunkelflauten, which is essential for planning resilient energy systems. With the connection of cold Dunkelflauten to Greenland Blocking weather regimes, weather regime forecasts on the subseasonal to seasonal time scale become an integral part of providing information to grid operators to prepare for potential shortages in supply.
Christian M. Grams (Institute of Meteorology and Climate Research (IMK-TRO), Department Troposphere Research, Karlsruhe Institute of Technology (KIT))
Tom Brown (Institute of Energy Technology, Department of Digital Transformation in Energy Systems, Technische Universität Berlin)
Fabian Neumann (Institute of Energy Technology, Department of Digital Transformation in Energy Systems, Technische Universität Berlin)