Hydrogen Pipelines
There are approximately 700 miles of hydrogen pipelines currently operating in the United States (compared to more than one million miles of natural gas pipelines nationwide). Owned by merchant hydrogen producers, these pipelines are located where large hydrogen refineries and chemical plants are concentrated (for example, in the Gulf Coast region).
Transporting gaseous hydrogen via existing pipelines is currently the lowest-cost option for delivering large volumes of hydrogen. The high initial capital costs of new pipeline construction, however, constitute a major barrier to expanding hydrogen pipeline delivery infrastructure.
Research is also focused on overcoming other technical concerns related to pipeline transmission, including the potential for hydrogen to embrittle the steel and welds used to fabricate the pipelines; the need to control hydrogen permeation and leaks; and the need for lower cost, more reliable, and more durable hydrogen compression technology.
One possibility for rapidly expanding the hydrogen delivery infrastructure is to adapt part of the natural gas delivery infrastructure to accommodate hydrogen. Converting natural gas pipelines to carry a blend of natural gas and hydrogen (up to about 20% hydrogen) may require only modest modifications to the pipeline; converting existing natural gas pipelines to deliver pure hydrogen may require more substantial modifications. Both approaches are being investigated.