Investigating Systemic Extrapolation of Distribution Grid Investment Costs

The impact of the additional integration of distributed energy sources or electrification of the heat and mobility sector on the distribution grids is analysed by numerous distribution grid studies. Some of the studies examine individual influences on the distribution grids and then extrapolate the results for a large area. To determine distribution grid investment costs for entire states or countries, individual representative regions are investigated, on which the results are then extrapolated to an entire area. However, which extrapolation method is chosen influences the overall results. In this paper, the impact of the extrapolation methods on the extrapolated results of distribution grid investment costs is investigated, considering different clustering parameterizations. To achieve this, we present a method for the systemic extrapolation of distribution grid investment costs by identifying representative regions, assigning individual grid models, analysing the expansion needs and finally using different extrapolation methods to analyse the range of extrapolated investment costs to the area of interest. In our results, we apply the method to a study scenario and compare the extrapolated results to show the relevance of the choice of extrapolation method.