Mid-Term Congestions Forecast in the German Transmission Grid

Abstract

A vast expansion of renewables has led to severe overloading situations in the German transmission grid. Available studies on grid expansion usually pursue a long term view although the currently observable delayed grid expansion leads to uncertainties in mid-term operations. Hence, it is necessary to assess the potential severity as well as location of these effects. This paper presents the spatial distribution of line congestions in the mid-term in the German 380/220 kV extra high voltage grid. To avoid an overestimation of congestions, the underlying high voltage grid structures are also considered. The results show severe overloads especially in Lower Saxony (DE) and the cross-border area Vierraden (DE-PL). Simulations underline, upcoming grid expansion measures contribute significantly to reducing these congestions. A partial removal of lignite generation capacity in Rhineland in contrast exacerbates grid congestions.