The energy transition in Europe and the transformation and conversion of renewable energy into sustainable solutions like Power-to-X (PtX), especially hydrogen or e-methanol (but also others) is getting more and more important and plays a key role in achieving the decarbonization targets of the energy system. The growing deployment of hydrogen electrolyzer PtX plants introduces new challenges for grid integration due to their scale, power‑electronics‑dominated behavior, and stringent grid code requirements.

This paper presents a structured approach for the verification of grid code compliance and the validation of electrical simulation models (mainly RMS based simulation models) for large‑scale hydrogen electrolyzer PtX plants. The methodology covers plant‑level studies and an simulation‑based assessments, complemented by on‑site commissioning tests to evaluate dynamic behavior under normal operation and various operation conditions. Particular attention is given to the load shedding functionality, where measurement results from field tests are used to verify model fidelity and control performance.

The validation process compares measured responses with RMS based electrical simulation models to identify deviations and ensure representative behavior during grid events. The study demonstrates how validated models can be reliably used for compliance assessment and system impact studies. Finally, the implications of the findings for future PtX projects are discussed, highlighting transferable lessons for developers, grid operators, and model validation processes for simulation models (RMS- and EMT based simulation models) of renewable energy co-located facilities. Furthermore, the authors will summarize present requirements for co-located facilities and provide some recommendations for further development of co-located requirements.