How can hydrogen be transported over long distances ?
Hydrogen is a very light substance but it takes a lot of space and is difficult to compress (very high pressures needed) or to liquify (very low temperatures needed). This makes it difficult and costly to transport from the place where it is produced to the place where it is used. The cheapest option is by pipelines very similar to natural gas pipelines. Like for natural gas, these pipelines can go up to 120cm diameter and a pressure of 80 bar. The main difference to gas pipelines is the need for tightness, since hydrogen is very fugitive and will escapee’s through thinest cracks and leaks. The pipeline equipment is similar except for the compressors, which need a new technology to handle the specific characteristics of hydrogen.
Most Pipelines built in the recent 30 years will basically be fit for hydrogen, the only thing that needs to be replaced are the compressors. Such repurposing of spare natural gase pipelines provides a convenient way for transition from natural gas to hydrogen since it is very cost efficient and estimated to save 90% of the cost compared to new pipelines. Transporting green hydrogen in such repurposed pipelines is estimated to cost only 9-17 ct per kg per 1000 km. (see EU Hydrogen backbone study)