ILF Consulting Engineers (hereinafter ILF) is currently involved in the design of several gas pipeline projects in Europe. The planned horizon and therefore the investments are considered for an operating life of >50 years. In this respect the questions arise how the current European developments in the use of hydrogen possibly affect those investments, and whether the generation of hydrogen from excess wind and solar energy and its admixture and transport in the existing pipeline grid require modifications of these pipeline networks.

In this respect ILF had been asked by one of its client to conduct an assessment to what degree such changes in the transported medium would be having influence for a specific pipeline system, which had been recently completed in respect to design aspects, which however has not been constructed yet. The study includes three scenarios with 2%, 5% and 10% hydrogen concentration. The study assessed a possible impact on the permit documentation, an impact related to the connected pipeline infrastructure and provided recommendations for modifications of the technical project documentation.

A second, separate, assessment assumed a 100% exchange of natural gas with hydrogen. For this approach a dedicated new “Basis of Design” for the project had been developed, now for pure hydrogen. This study covers design aspects of a hydrogen pipeline, such as flow scenarios, venting and first fill considerations, material aspects, aspects related to station design, hazardous areas and many more. A sub-sequent “Gap Analysis” between this new developed “Basis of Design” and the existing project documentation had been conducted and resulting conclusions drawn in respect to the main technical differences. It was further concluded, which technical modifications would be required, if the pipeline currently designed for natural gas, shall be at some point in the future be converted into a 100% H2 compatible pipeline.