The European natural gas infrastructure offers an opportunity to feed in hydrogen (H₂), integrating low-carbon gases while leveraging the existing gas network and contributing to decarbonization. In subtask 4.2 of SHIMMER, SINTEF developed and implemented extensions of the energy system optimisation model EMX to analyse the timing and sizing of infrastructure investment to facilitate the phasing in and transport of hydrogen supply in natural gas networks. The model has been applied to case studies in the project to perform analyses of transmission networks in Norway and Spain. Our main findings include the following:
- Hydrogen admixing can be a cost-effective option for delivering significant volumes of hydrogen, but the potential is closely interrelated with the need for natural gas transport.
- The transported volumes of natural gas often limit how much hydrogen can be injected when considering hydrogen blending limits. Depending on policy and market incentives, gas flows may be routed differently to accommodate higher levels of hydrogen admixing.
- For transporting large hydrogen volumes, dedicated pipelines are preferred.
- High opportunity cost of natural gas exports is a barrier to repurposing pipelines for pure hydrogen transport. As the need for natural gas transport is reduced, repurposing becomes more attractive.
- Buffer storage for hydrogen can be used to shift injection of hydrogen from variable production in time and exploit the capacity of existing natural gas for admixing.
- With premium H₂ prices, deblending can be used to extract extra revenue and stay below terminal blending limits if the upstream network has higher capacity for admixing.
