arXiv:2610.40822v1 Announce Type: new Abstract: Future hydrogen systems depend on large-scale storage to balance supply and demand. Hydrogen networks can store energy in the pipelines themselves, but the potential of this linepack storage has not been quantified comparably to dedicated storage facilities. We transfer metrics established for conventional storage, such as volume capacity and full-cycle equivalents, to hydrogen networks. To evaluate them, we formulate an optimization problem maximizing linepack storage utilization, subject to non-convex PDE-based constraints describing transient gas flow. We solve the optimization problem over a full-year horizon to capture seasonal variations and to assess the interaction with cavern storage. For computational tractability, we propose a simulation-informed sequential convex programming approach with adaptive time stepping that reduces problem size by up to 98% at accuracy comparable to fixed-resolution methods. For the GasLib-40 topology with German scenario data, the network provides a volume capacity of 24 million normal cubic meters at 28 full-cycle equivalents per year.