Impact of the integration of renewable energies on the reactive power demand in the German transmission grid

The energy transition, which leads to shutdowns of conventional power plants with simultaneous expansion of renewable energy power plants, causes a strong change in the utilization of the transmission grid. It has to handle larger transport tasks, whereby the reactive power demand increases. At the same time fewer conventional power plants are available to balance the reactive power demand of the grid. In this paper, a model is presented to determine the reactive power demand in power transmission systems. In the simulation part the model is applied to Germany for the years 2011 and 2033 and the future development in the amount of locally needed reactive power supply is determined. Opportunities are identified to cover remaining reactive power demands, which cannot be provided by existing power plants. In an economic analysis these different reactive power sources are compared to supply the needed reactive power at minimal costs.