The Influence of Different Network Tariffs on Distribution Grid Reinforcement Costs

The transition towards a renewable power grid raises various challenges in distribution grids, potentially leading to significant future reinforcement needs. This project analyses how different network tariffs can mitigate grid reinforcement by steering the use of decentralised flexibility options, namely curtailment of photovoltaic generation, battery storage systems, smart charging, and usage of thermal energy storage to shift heat demand. Therefore, the reaction of prosumers with different combinations of these flexibility options is modelled by a cost-minimising consumer-based optimisation. With these, a case study for six different grids in Germany is conducted for various combinations of different energy- and capacity-based tariff components. The analysis shows that time-varying energy-based components such as a day/night energy tariff or time-varying suppliers' cost lead to a synchronisation of the flexibility options. This synchronisation can increase grid reinforcement costs, depending on the penetration of flexibility options and the user preference. On the other hand, capacity-based tariff components on peak load and feed-in generally reduce the costs. However, these components can also reduce synergies between closely located users in specific situations. Overall, the tariff with a constant energy component and capacity components on peak load and feed-in shows the highest potential to reduce the reinforcement costs, showing a reduction of 9.5 % in all the investigated grids.