On synergies between congestion management instruments: The Dutch case-study

To address grid congestion in distribution networks, Distribution System Operators (DSOs) are exploring new congestion management instruments. Since 2022, market parties in The Netherlands can provide congestion management through capacity- and energy-based bilateral contracts. Additionally, new grid tariffs are being explored that incentivize peak shaving for small end-users. However, the interactions between these instruments are not well understood. This paper presents an integrated modeling approach to analyze the interplay between three grid tariff candidates and the two bilateral contract types in a low-voltage setting. Prosumers and congestion service providers (CSPs) are modeled using economic moving-horizon control, and a novel mixed-integer second-order cone programming formulation is introduced for day-ahead bilateral contract activation by the DSO. Results show that a seasonal peak tariff is the most effective tariff, particularly in mitigating load synchronization issues due to low market prices. Combining grid tariffs with bilateral contracts effectively managed congestion in summer. In winter, when congestion was caused by electric vehicles, adding active congestion management to the grid tariffs through contracts proved only beneficial if CSP portfolios contained sufficient flexibility. These findings highlight the need to carefully consider asset types, available flexibility, and market conditions for effective congestion management.