A case study for the stepwise conversion of a regional mid pressure natural gas network for hydrogen transmission

Hydrogen plays a central role in the Netherlands’ decarbonization strategy. Gasunie, the national transmission operator, is repurposing existing natural gas infrastructure to build a hydrogen network, with the high-pressure system expected by the 2030s. The next phase focuses on converting regional pipelines to support industry and residential areas. This research develops a methodology to assess regional pipeline suitability for hydrogen, using Groningen and Ameland as case studies. The framework evaluates material integrity, transmission velocity, pressure drop, and risks like diffusion, leakage, and fatigue. Nationally, 99.7 % of pipeline materials are suitable, though 4-inch pipelines post-1982 may contain unexaminable defects. Additionally, 23 pipelines (53.85 km) exceed velocity limits under extreme scenarios, and maximum hydrogen diffusion could reach 1.1⋅10 2 m 3 H 2 per year in the worst case (no present oxide layer). The methodology enables a stepwise, cost-aware network conversion and offers a practical tool for transmission and district operators across the Netherlands and Europe.