Simulation of Distribution Grid Expansion Costs and the Impact of Load Shifting

The increasing electricity generated by the renewable energy generation units connected to the distribution grid can lead to the allowed level of voltage range and current rating in the lines being exceeded. One option to prevent this from happening is line extension. This article describes a method of quantifying the line extension, its costs and the impact of load shifting which can be used in electricity system models. The region considered is the state of Baden-Württemberg in Germany. The operation of the distribution grid is simulated based on region-specific electricity demand and electricity generation. In order to use the voltage range of 10% (based on DIN EN 50160) completely, the countrywide installation of regulated distribution transformers is assumed. The allowed level of voltage and current rating is mainly exceeded in regions with a high supply of photovoltaic electricity at the low voltage level. With the modelled assumptions and the extension of renewable energy under consideration, an expense of about 760–880 million Euros in Baden-Württemberg will be required by the year 2030 to ensure that the operation complies with the technical restrictions. By using load shifting, the expense can be reduced by 140–220 million Euros.