Pioneering work for the energy transition
Gasunie’s Hyperlink project marks the start of work to build an efficient hydrogen infrastructure in north-western Germany. Converted existing natural gas pipelines will make up around 60% of the future hydrogen network. This approach conserves resources and allows parts of the Hyperlink backbone to be put into operation quickly. Project Manager Lara Hauck looks back on the conversion work that was completed in 2023 and details the tasks ahead.
‘When we started working on the engineering design for the Hyperlink 1 & 2 conversion projects at the beginning of 2023, the challenges seemed immense at times,’ Lara says. ‘The fact that we succeeded in fully preparing the first pipeline section in our existing network for future hydrogen transmission that same year is primarily due to the enormous commitment of everyone involved. This applies both to our colleagues at Gasunie and to the smooth and close collaboration with our service providers. I am particularly proud that we were able to lay down the last weld in time for Christmas.’
Molecule size and flow velocity
Lara heads up a ten-strong project team at Gasunie Deutschland, which is responsible for the conversion aspects of the Hyperlink 1 and 2 sub-projects. Due to the small molecular size and high flow rate of hydrogen compared to natural gas, the fittings in existing natural gas pipelines, particularly the older ones, do not meet the technical requirements for hydrogen transmission. From a technical perspective, repurposing the pipelines often is pioneering work as there are no blueprints for projects of this nature and the technical regulations are still being developed. As the work has to be carried out close to operational gas pipelines (brownfield sites), the core team is receiving support from a newly formed GOW-H hydrogen team in the Operations division.
Finally, in early September 2023, the first modifications for the Hyperlink conversion were made to ETL 0015, a natural gas pipeline that has been in operation for around 60 years. Over the course of 15 weeks, modification work was successfully carried out at a total of eight sites along the 55-kilometre pipeline run from Ottersberg to Heidenau. The work involves taking the pipeline section concerned out of service first and then excavating down to the pipeline at the relevant locations to replace the relevant fittings, remove system components and replace them with pipeline adapters and/or carry out other activities. The time needed at a particular site can range from a few weeks to several months, depending on the scope of the work. After completion of the work on the pipeline, the pipeline run was put back into operation for natural gas transmission at Christmas. Remaining work, such as foundation construction, backfilling the excavations and relandscaping the surface, was completed by May 2024.
Strict safety precautions
Specific requirements apply to work at a brownfield site. ‘As the pipelines in the vicinity of our work sites are still in operation, we have to observe strict safety precautions. You also don’t know what surprises lie in wait as you excavate down to the pipeline,’ explains Lara. ‘However, largely thanks to the impressive expertise of our colleagues in the team, we were able to overcome all these challenges and complete the work in a very short space of time.’
‘We have learned a lot during the past year. So we are confident about the future and are looking forward to the next projects. Around 24 modifications are planned on four pipelines in 2024, including work at both Weser culverts, the Achim compressor station and the Eckel station,’ says Lara. ‘We haven’t had much time to rest though, because the first works have already begun.’