The energy transition is changing the German electricity supply system fundamentally. As a result of the expansion of electricity generation from renewable energy sources, the electricity grid infrastructure for transmission and distribution must be expanded. Electricity distribution grids in particular need expansion and conversion, not just the electricity transmission grid. Today, most of the regenerative generation capacity is connected to the electricity distribution grid, and that will remain the case in future. Without expansion and conversion of these grids, we will be unable to utilise fully the renewable generation capacity installed by 2030 for electricity supply in Germany.
The dena Distribution Grid Study is a detailed examination of the need for expansion and conversion in the German electricity distribution grids based on two alternative expansion scenarios for renewable energy sources. The results confirm a significant need for enlargement by 2030. It also analyses technical options for reducing the grid expansion requirements. In particular, the use of innovative grid operational resources, the adaptation of technical guidelines and down-regulation of generation peaks of decentralised power generation units could reduce the need for grid expansion. However, further research into the efficiency and technical design of these measures is required. The analyses in the dena Distribution Grid Study also reveal that the current regulatory framework conditions place distribution grid operators with major expansion requirements at a disadvantage. They do not receive sufficient returns for implementing the necessary expansion of the grids.