Large-Scale Integration of Electrolyzers into the German Transmission System: A 2030 Scenario

Energy system planning relies on large-scale optimization models for cost-effective generation and storage expansion. However, their operational feasibility, particularly regarding power system dynamics, remains a critical gap. This paper presents a framework that bridges techno-economic energy modeling with dynamic power system simulations. By integrating PyPSA-Eur with DIgSILENT PowerFactory, the framework automates the transition from optimized planning to stability assessment. The framework is demonstrated through the integration of large-scale electrolyzers into the German transmission system for 2030, evaluating their impact on power flows, short-term voltage stability, and reactive power compensation. The study highlights that HVDC links and electrolyzers enhance power dispatch flexibility, reducing transmission overloading, while electrolyzers introduce significant reactive power demands due to their thyristor-based power supply, requiring dedicated compensation strategies. A power dispatch algorithm, used to simulate 17,520 hourly scenarios in PowerFactory, supported by machine learning techniques, enables a full-year, large-scale assessment of operational variability. The proposed framework aids grid operators in evaluating network expansion, system stability, and the reliable integration of new generation and storage technologies.