In addition to the existing cost hurdles, widespread hydrogen usage will require a substantial investment in infrastructure to safely transport and store the volatile gas and provide convenient refueling options in addition to scaling up production. For example, there are 1,600 miles of hydrogen pipelines in the US, but over 3 million miles of natural gas pipelines, some of which could be retrofitted to transport hydrogen. Most of the major oil companies including Shell, Exxon, Chevron, and BP are aggressively engaged in research and deployment of commercial-scale green hydrogen production and transportation capabilities.