Hydrogen has over the last century enjoyed repeated bouts of interest as a fuel source. Though these have repeatedly fallen flat, hydrogen-based production has recently enjoyed a renaissance, due to a trifecta of improving political, economic, and technological conditions. Importantly, hydrogen presents an answer to a major problem in the energy transition debate: decarbonizing fuel sources while maintaining energy security and reliability. While electrification has a first-mover advantage in certain areas (e.g., light-duty vehicles), hydrogen is seen as particularly viable in “hard-to-decarbonize” sectors such as heavy-duty transportation, which requires fuel supply for substantial distance and payloads.
These trends are still nascent. There has long been a small hydrogen market, primarily for industrial applications;1 however, there is currently not large-scale distribution. For example, there are approximately 1,600 miles of hydrogen pipelines in use today, compared with approximately 3 million miles for natural gas pipelines.2 This mirrors the currently low volumes of production in the hydrogen market, only around 70 megatonnes (“Mt”) produced globally each year.3 But market dynamics are changing. Some estimates predict U.S. demand alone to require approximately 63 Mt per year by 2050.4 Additionally, there is increasing interest in low-carbon hydrogen to replace current fossil fuel-based production of hydrogen.5
However, acting upon the growth of a hydrogen economy requires addressing the currently underdeveloped infrastructure, both physical6 and regulatory. Multiple agencies have authority that touches at least tangentially on hydrogen, but there is currently no comprehensive hydrogen regulatory regime for the United States. Agencies are often aware of their ability to regulate hydrogen, and recent developments—such as the Department of Energy’s (“DOE”) newly revised Hydrogen Program Plan7—suggest that they are starting to act. Currently, the main agencies with the ability to influence the development of hydrogen industry and infrastructure include: the DOE, the Federal Energy Regulatory Commission (“FERC”), the Pipeline and Hazardous Materials Safety Administration (“PHMSA”), and the Environmental Protection Agency (“EPA”). In the remainder of this white paper, we explore this regulatory landscape and potential next steps by agencies.
Hydrogen is the most abundant element in the universe.8 It can be produced by utilizing a wide array of sources, including natural gas, electricity, solar heat, and biogas.9 Currently, hydrogen is used mainly for oil refining and the production of certain industrial products (such as ammonia, methanol, and steel).10 However, its allure as a fuel is that its only combustion byproduct is water vapor.11 The production of hydrogen, on the other hand, can involve significant emissions. Fossil fuels are used for most present-day hydrogen production, with the predominant method being steam reforming of methane from natural gas.12
Hydrogen is generally classified based on the resource used to produce it. The four most commonly used classifications (labeled as colors) are:
Due to the fact that both the input and the output of green hydrogen are carbon-neutral, many companies are eager to bring it forward as an energy source.13 Blue hydrogen provides a method for fossil fuel companies to have a pivotal role in the development of the industry as well. Moreover, hydrogen, especially blue and green hydrogen, could help solve the energy industry’s problem with transportation of energy generated from renewable sources, as it is a jack-of-all-trades option – a highly versatile substance that can be combusted, compressed, or liquefied, or used to store or produce energy for electricity. Hydrogen can be transported via pipeline (potentially repurposing existing natural gas pipelines) or via truck, rail, or vessel. It also does not share certain logistical concerns faced by other fossil fuel alternatives. For example, hydrogen does not have the same stigma and siting concerns as nuclear power generation.14 Hydrogen also has a quick fueling time and can be stored effectively for long-haul voyages, issues that have plagued certain electrification efforts.15 And as a final feather in hydrogen’s cap, it has relatively few known sustainability risks related to potential environmental or human rights consequences in the value chain.16
Thus, there are substantial incentives to develop large-scale hydrogen production, particularly for sectors that are difficult to decarbonize via electrification.
Despite the lack of a comprehensive regulatory scheme, the U.S. government has recognized hydrogen’s potential as a fuel source. Thus far, the federal government’s major initiative regarding hydrogen as a fuel source has been to incentivize research in the area, including by funds made available through programs in multiple agencies.17 One of the most important is DOE’s $100 million pledge, which reflects DOE’s intention to invest up to this amount in two new DOE National Laboratory-led consortia to advance hydrogen and fuel cells technology research, development, and demonstration (“RD&D”) over the next five years.18 One consortium will develop affordable, commercial-sale electrolyzers, which use electricity to divide water into hydrogen and oxygen, and the other consortium will assist in accelerating the development of fuel cells for vehicles, specifically for long-haul trucks.19 In November 2020, DOE released its updated Hydrogen Program Plan, which underscores DOE’s department-wide commitment to facilitating the growth of hydrogen as a source of energy and provides a “strategic framework for the Department’s hydrogen [RD&D] activities.”20
While this is undoubtedly an important aspect of developing the hydrogen economy, the federal government will need to incorporate hydrogen into its broader regulatory scheme for hydrogen to truly become part of the energy infrastructure in the U.S. Much of this may fall on agencies other than DOE. Several federal agencies already address hydrogen in their regulations; however, they only address it incidentally, as one of the many substances regulated under their regimes. For example, most environmental regulations on hydrogen deal with hydrogen’s properties, such as its flammability/explosivity (which often requires it to be regulated as a hazardous substance). These regulations are scattered throughout the Code of Federal Regulations (“C.F.R.”), and are not organized to address hydrogen in a cohesive manner. Instead, disparate regulations touch upon a portion of the hydrogen industry or issues related to the characteristics of hydrogen itself, but do not focus on regulation of the hydrogen industry as a whole.
Currently, the federal agencies with the most extensive regulation of hydrogen are the Occupational Safety and Health Administration (“OSHA”), EPA, and PHMSA. Hydrogen regulations are not a central part of these agencies’ missions, but the agencies will continue to play an important role as hydrogen becomes more prevalent and technologies advance and change.
OSHA is responsible for creating Occupational Health and Safety Standards, housed in Title 29 of the C.F.R. Subpart H of Title 29 covers the Occupational Health and Safety Standards for Hazardous Materials – including compressed gases and hydrogen. 29 C.F.R. § 1910.103 covers the installation of hydrogen systems, regulating several aspects: location; containers and piping characteristics; safety relief devices; equipment assembly; marking; and testing, among others.
While 29 C.F.R. § 1910.103 is the main OSHA regulation governing hydrogen, there are other sections of the Occupational Health and Safety Standards for Hazardous Materials that ostensibly could regulate hydrogen. For example, hydrogen will likely be compressed or liquefied in several situations, which may implicate OSHA safety standards for compressed gases and flammable liquids. While these regulations currently do not explicitly reference hydrogen, they could be applied to hydrogen as part of a larger integration of hydrogen into the regulatory scheme.
The EPA regulates substances that have an impact on human health and the environment.21 This mandate includes a broad array of substances, including hydrogen. The EPA’s regulations on hydrogen are a prime example of the haphazard way in which hydrogen has been regulated by the U.S. federal government to date. Primary regulation of hydrogen by EPA is found under the Mandatory Greenhouse Gas Reporting Program (“GHG Reporting”), Effluent Standards under the Clean Water Act, and Chemical Accident Prevention program. In each instance, hydrogen is listed not due to any systematic consideration by EPA of regulations that may be needed for hydrogen under the agency’s mandate, but instead because of hydrogen’s relationship to that program.
Both the GHG Reporting and Effluent Standards regulate production of hydrogen as an offshoot of regulations on fossil fuel processing. The broader program for GHG Reporting, found in 40 C.F.R. Part 98, requires reporting of greenhouse gas (“GHG”) data from large GHG emission sources, fuel and industrial gas suppliers, and CO2 injection sites in the U.S.22 40 C.F.R. § 98.160 specifically imposes these reporting requirements onto hydrogen production from process units that produce hydrogen by transforming feedstocks (e.g., the methane steam reformation process used to produce grey hydrogen).23 Any such hydrogen production source that emits 25,000 metric tons of CO2 must comply with GHG reporting, as specified in 40 CFR § 98.160 et seq.,24 which also includes monitoring requirements as well as quality assurance and quality control procedures.25 The Effluent Standards also derive from the regulation of hydrogen production from fossil fuel sources. Not only do the Effluent Standards apply to discharges of materials to water that result from the production of hydrogen as a refinery by-product,26 but the standards themselves ultimately refer back to those regulations in the petroleum refining part of the chapter.27
Similarly, the EPA’s Chemical Action Prevention scheme only regulates hydrogen tangentially. The regulations are found in 40 C.F.R. Part 68 and were created to implement part of the Clean Air Act. This scheme is not specifically focused on hydrogen, but establishes requirements for chemical risk management applicable to facilities storing certain listed substances in quantities above a certain threshold.28 These regulations require a risk management program complying with certain requirements (and including provisions for accident prevention and response) for facilities storing hydrogen in a quantity over a threshold amount of 10,000 pounds.29
While these regulations all address hydrogen, they suggest that hydrogen was not the focal point of the regulatory process establishing these regulations. If hydrogen (particularly green hydrogen) grows as a fuel source and becomes material to economic channels, then EPA will likely need to revisit its regulatory approach.
PHMSA’s mission is to protect human health and the environment by promoting the safe transportation of energy and other hazardous materials by creating national policy, setting and enforcing industry standards, and conducting research.30 PHMSA currently regulates approximately 700 miles of hydrogen pipelines via 49 C.F.R. Part 192.31 These regulations are primarily focused on natural gas, but the definition of gas under this provision includes “flammable gas”, which brings hydrogen into play.32 However, due to the fact that the primary focus of these regulations is natural gas, certain characteristics of hydrogen are not necessarily fully contemplated in some of the existing regulations’ design requirements. Nonetheless, in light of PHMSA’s goals and the intent of its regulations, PHMSA currently is conducting research regarding hydrogen’s effects on steel pipelines.33
PHMSA does administer some regulations that more specifically focus on hydrogen. For example, 40 C.F.R. §§ 173.230, 173.301, and 173.302 regulate hydrogen in transportation. In addition, 40 C.F.R. § 173.230 imposes certain requirements for the design, filling, and marking of hydrogen fuel cells, and 40 C.F.R. §§ 173.301 and 173.302 impose general requirements on the transportation of compressed gases, including compressed hydrogen. These regulations provide some guidance on the use of hydrogen, but fall short of creating a comprehensive regulatory regime that will guide the development of the entire industry.
As discussed above, hydrogen has yet to be comprehensively integrated into federal regulation. Several other federal agencies may have roles to play in the nascent hydrogen economy, but most (if not all) have yet to fully embrace that role. Quite a few federal agencies have regulatory mandates that could touch on hydrogen or its uses, and there are increasing calls to use these mandate [as the basis] to develop a regulatory infrastructure for hydrogen. If hydrogen comes to the fore, these agencies will likely have to assess whether to devote greater regulatory attention to hydrogen, either under current regimes or new ones developed for hydrogen specifically. Although the specific agencies that will act first and the resulting regulatory regimes that will arise cannot be predicted with any certainty, below are some of the regulatory developments related to hydrogen that may occur at the federal level.
DOE will likely continue to play a significant role in the development and testing of new hydrogen technologies. As briefly discussed above, the DOE recently issued its Hydrogen Program Plan.34 The Hydrogen Program Plan describes DOE’s high-level, cross-agency strategy for fostering the hydrogen economy by funding research and development. The Hydrogen Program Plan analyzes potential uses of funding for hydrogen development, primarily focusing on hydrogen’s role in power generation and transportation, sectors in which hydrogen could become more prevalent if technological advances made it financially accessible and environmentally sustainable.35 The Hydrogen Program Plan likewise discusses potential advances to be made in chemical and industrial processes, where hydrogen traditionally has been used. DOE also envisions itself playing a role in incentivizing the use of hydrogen in fuel cells, especially for long-haul trucks.
In addition, the DOE’s Hydrogen Program Plan examines the production, storage, and transportation of hydrogen, specifically methods to make carbon-neutral or carbon-negative hydrogen an affordable reality.36 This means evaluating all possible methods of producing hydrogen – fossil fuels, renewable energy, nuclear energy, and methanol.37 The DOE seeks to enable the hydrogen transition, primarily through research and development and funding, and appears to be preparing for a role as the thought leader on the integration of hydrogen into the broader energy scheme. While the DOE Hydrogen Program Plan does not specifically seek to regulate hydrogen itself, the Plan lays out a comprehensive strategy to foster the development of hydrogen as a substantial component of the energy and transportation sectors.
FERC could seek to establish regulatory provisions for the interstate transportation of hydrogen. Pursuant to the Natural Gas Act (“NGA”), the Federal Energy Regulatory Commission (“FERC”) regulates the siting, construction, and operation of interstate natural gas pipelines and storage, and the rates and terms of service offered by these pipelines.38 While FERC has not utilized this authority to regulate pipelines exclusively transporting hydrogen, and may not have jurisdiction to do so under the NGA or other existing statutes, it is possible that FERC could regulate the transportation of hydrogen if it is transported in a blended stream with natural gas. While gaseous hydrogen generally is currently transported through designated hydrogen-specific pipelines,39 it also can be found alongside natural gas in natural gas transmission pipelines. Several groups have posited that one way to transport hydrogen and make the end-use of hydrogen cheaper could be to integrate the transportation of gaseous hydrogen into existing natural gas pipelines in greater quantities, blending hydrogen with the natural gas stream.40 The transportation and construction of natural gas pipelines is squarely within FERC’s authority under the NGA, and accordingly, transportation of hydrogen blended in these pipelines could subject hydrogen transportation to regulation by FERC.
FERC’s regulations of natural gas pipelines extend beyond the regulation of construction of pipeline facilities and also apply to the terms and conditions of transportation services. FERC regulations require natural gas companies to file a tariff that sets forth the terms and conditions of service on the natural gas company’s pipeline, including terms and conditions related to the quality of the gas being transported. Including greater quantities of hydrogen in the natural gas stream on FERC-regulated natural gas pipelines could require modification of existing gas quality provisions in a pipeline’s tariff, and likely would require coordination with shippers and other pipelines in order to accommodate additional hydrogen content. This coordination and the balance of pipeline and shipper interests is familiar territory for FERC and its regulated natural gas companies, and the existing regulatory regime may have benefits if applied to the transportation of hydrogen.
FERC may encourage hydrogen production by classifying it as a “useful thermal energy output” that would entitle some cogeneration facilities to beneficial regulatory treatment.41 FERC is also responsible for implementing regulations under the Public Utility Regulatory Policies Act of 1978 (“PURPA”). PURPA provides a number of benefits to certain qualifying electricity generating facilities, including the right to sell energy or capacity to certain utilities, the right to purchase certain services from utilities, and relief from certain regulatory burdens.42 FERC has announced that it is considering whether to expand its PURPA regulations to allow a specific hydrogen-based technology, a solid oxide fuel cell system, “that then uses the thermal energy it produces to reform methane and produce hydrogen for electricity generation”, to qualify for this beneficial regulatory treatment. FERC issued the Notice of Proposed Rulemaking on this issue on October 15, 2020, and comments were due to FERC on November 25, 2020. If the proposed rule is issued after FERC’s review, the resulting Final Rule could open up another avenue of support for hydrogen production through better rate and regulatory treatment.
EPA may develop new regulatory standards for hydrogen production that are distinct from fossil fuel processing. EPA’s regulatory mandate is wide, and there are multiple potential touchpoints as a hydrogen economy is developed. Many of these will depend on trends in the industry that will require some trial-and-error to establish, such as preferred distribution channels. EPA has not yet provided significant guidance on how it sees its role in a hydrogen economy; however, our survey of EPA’s current regulations suggests that they may be ill-fitting to a future where hydrogen has moved from a peripheral to a core focus for energy companies. EPA may, therefore, decide it needs to expand its regulations of the field.
For example, effluent discharges from grey hydrogen production are currently only related to by-products of the petroleum refining process; however, if already processed fossil fuels are being directed specifically for hydrogen production, then it is less clear that EPA’s current regulations would capture those discharges. Similarly, the EPA’s GHG Reporting requirements for hydrogen production only apply to hydrogen produced from feedstocks, not electrolysis. If fossil fuels, or even renewables, are used for the electrolysis, then any environmental characteristics of that energy currently are not captured in the GHG Reporting requirements related to hydrogen production. While the EPA may not need to change its mechanism or standard of review under any of these statutory schemes in order to accommodate hydrogen, the EPA may need to expand its review of hydrogen with respect to impacts on human health and the environment, which may require the creation of more detailed and comprehensive hydrogen regulations. While many of these regulations would likely be created in dialogue with the development of the hydrogen industry, they provide several avenues for EPA to revise or expand upon current regulations for the new industry.
PHMSA may introduce hydrogen-specific storage and transportation requirements. PHMSA has stated that it has a “need to focus on supporting activities to ensure that hydrogen is transported safely”43 and identified that it needs a “clear technical focus regarding safety implications of infrastructure materials, designs and systems; preparations to address any regulatory barriers towards a hydrogen economy; research in support of additional industry consensus standards; [and] efforts to educate and prepare emergency responders.”44 As discussed above, PHMSA’s regulations that govern hydrogen transported in pipelines were created to handle natural gas. However, given the molecular differences between the two substances, regulations focused on natural gas may not be enough to fully encompass the needs of a hydrogen pipeline system. For example, hydrogen can embrittle and accelerate the growth of cracks in pipelines, and can more easily permeate elastomer seals and plastic pipe than natural gas, all of which increase the risk of pipeline failure.45 The existing safety regulations likely only contemplated small-scale usage of hydrogen,46 and will need to be expanded to handle hydrogen transportation on a larger, commercial scale. Based on these industry-identified concerns, PHMSA determined several key research items that will lead to the development of specific standards and engineering designs and systems for the transport of hydrogen by pipeline:
PHMSA may need to create new regulations or expand the existing regulations based on the results of the research tasks described above in order to combat the risks associated with hydrogen transportation by pipeline.
The confluence of several trends has the potential to ignite a burgeoning hydrogen industry, but the build-out will require significant development of not only physical but also regulatory infrastructure. Several agencies have regulations addressing hydrogen, but they do so only incidentally. A hydrogen economy will require more comprehensive and deliberate regulation of hydrogen value chains. Of the agencies whose mandates touch on hydrogen, the most significant regulatory actions are likely to come from DOE, FERC, EPA, and PHMSA. Vinson & Elkins remains ready to help our clients navigate these regulatory challenges and questions and to implement projects and strategies that capitalize on the growing global interest in hydrogen.
1 Int’l Energy Agency, The Future of Hydrogen 89 (2019) (“IEA Report”).
2 Compare Hydrogen Pipelines, Dep’t of Energy, https://www.energy.gov/eere/fuelcells/hydrogen-pipelines (last visited Dec. 3, 2020) with Natural Gas Pipelines, Energy Info. Admin. – Natural Gas Explained, (Dec. 15, 2019) https://www.eia.gov/energyexplained/natural-gas/natural-gas-pipelines.php#:~:text=The%20U.S.%20natural%20gas%20pipeline,and%20storage%20facilities%20with%20consumers.
3 IEA Report, supra note 1, at 37.
4 See McKinsey & Co. et al., Road Map to a U.S. Hydrogen Economy 24 (2020) available at https://static1.squarespace.com/static/53ab1feee4b0bef0179a1563/t/5e7ca9d6c8fb3629d399fe0c/1585228263363/
5 See IEA Report, supra note 1 at 38–44.
6 See id. at 67.
7 See Dep’t of Energy, Hydrogen Program Plan (2020), available at https://www.hydrogen.energy.gov/pdfs/hydrogen-program-plan-2020.pdf (“Hydrogen Program Plan”).
8 Piyali Roy, Hydrogen is the Most Common Element: Here’s the Reason Why, Sci. Times (Apr. 3, 2017), https://www.sciencetimes.com/articles/11524/20170403/hydrogen-is-the-most-common-element-heres-the-reason-why.htm.
9 Production of Hydrogen, Energy Info. Admin – Hydrogen Explained (Jan. 21, 2020), https://www.eia.gov/energyexplained/hydrogen/production-of-hydrogen.php.
10 IEA Report, supra note 1.
11 Jeff Carbeck, Green Hydrogen Could Fill Big Gaps in Renewable Energy, Sci. American (Nov. 10, 2020), https://www.scientificamerican.com/article/green-hydrogen-could-fill-big-gaps-in-renewable-energy/.
12 IEA Report, supra note 1, at 38–39.
13 Carbeck, supra note 11.
14 See Hayley Cox, Why It’s Time to be Frank About Nuclear, Univ. of Manchester (June 28, 2017), https://www.mub.eps.manchester.ac.uk/science-engineering/2017/06/28/time-frank-nuclear/.
15 Hydrogen Basics, Alt. Fuels Data Ctr., https://afdc.energy.gov/fuels/hydrogen_basics.html (last visited Dec. 7, 2020).
16 See Chris Tattersall & Will Rohr, Are Hydrogen Cars an Eco-Friendlier Alternative to Electric?, Deloitte – Perspectives, https://www2.deloitte.com/ch/en/pages/energy-and-resources/articles/hydrogen-vs-electric-cars-sustainability-lens.html (last visited Dec. 7, 2020).
17 See, e.g., Airport Zero Emission Vehicle and Infrastructure Incentives Pilot Program, Fed. Aviation Admin., https://www.faa.gov/airports/environmental/zero_emissions_vehicles/ (last visited Dec. 3, 2020); Alternative Fuel Tax Exemption, Alt. Fuels Data Ctr., https://afdc.energy.gov/fuels/laws/HY?state=US (last visited Dec. 3, 2020).
18 Michael Bates, DOE to Invest in Advancement of Hydrogen and Fuel Cell R&D, NGTNews (June 25, 2020), https://ngtnews.com/doe-to-invest-in-advancement-of-hydrogen-and-fuel-cell-rd.
20 Dep’t of Energy, Energy Department Releases Its Hydrogen Program Plan (2020), available at https://www.energy.gov/articles/energy-department-releases-its-hydrogen-program-plan.
21 About EPA, Envtl. Prot. Agency, https://www.epa.gov/aboutepa (last visited Dec. 3, 2020).
22 Greenhouse Gas Reporting Program (GHGRP), Envtl. Prot. Agency, https://www.epa.gov/ghgreporting (last visited Dec. 3, 2020).
23 40 C.F.R. § 98.160 (2020).
24 40 C.F.R. § 98.2, Table A-4 (2020).
25 Envtl. Prot. Agency, Annex 8 QA/QC Procedures (2020), available at https://www.epa.gov/sites/production/files/2020-02/documents/us-ghg-inventory-2020-annex-8-qaqc-procedures.pdf.
26 40 C.F.R. § 415.410 (2020).
27 40 C.F.R. § 415.412 (2020).
28 40 C.F.R. § 68.12(a) (2020).
29 40 C.F.R. § 68.130, Table A (2020).
30 PHMSA’s Mission, Pipeline & Hazardous Materials Safety Admin., https://www.phmsa.dot.gov/about-phmsa/phmsas-mission (last visited Dec. 2020).
31 Hydrogen, Pipeline & Hazardous Materials Safety Admin. – Pipeline Safety Stakeholder Communications https://primis.phmsa.dot.gov/comm/hydrogen.htm (last visited Dec. 2020).
32 49 C.F.R. § 192.3 (2020).
33 Hydrogen, Pipeline & Hazardous Materials Safety Admin. – Pipeline Safety Stakeholder Communications https://primis.phmsa.dot.gov/comm/hydrogen.htm (last visited Dec. 2020).
34 Hydrogen Program Plan, supra note 7.
35 Id. at 7.
36 Id. at 3.
38 Lawrence R. Greenfield, An Overview of the Federal Energy Regulatory Commission, FERC.gov (June 2018), available at https://www.ferc.gov/sites/default/files/2020-07/ferc101.pdf.
39 Hydrogen, Pipeline & Hazardous Materials Safety Admin. – Pipeline Safety Stakeholder Communications https://primis.phmsa.dot.gov/comm/hydrogen.htm (last visited Dec. 2020).
40 See, e.g., Hydrogen Pipelines, Dep’t of Energy, https://www.energy.gov/eere/fuelcells/hydrogen-pipelines (last visited Dec. 3, 2020)
41 A cogeneration facility is a facility that produces a useful thermal energy output and electricity. Fuel Cell Thermal Energy Output, 173 FERC ¶ 61,050 at PP 8-9 (2020) (“Notice of Proposed Rulemaking”).
42 16 U.S.C. § 824a–3 (2018); PURPA Qualifying Facilities, Fed. Energy Reg. Comm’n, https://www.ferc.gov/qf (last accessed Dec. 8, 2020).
43 Hydrogen, Pipeline & Hazardous Materials Safety Admin. – Pipeline Safety Stakeholder Communications https://primis.phmsa.dot.gov/comm/hydrogen.htm (last visited Dec. 2020).
45 PG&E Gas R&D and Innovation, Pipeline Hydrogen 4 (2018) available at https://www.pge.com/pge_global/common/pdfs/for-our-business-partners/interconnection-renewables/interconnections-renewables/Whitepaper_PipelineHydrogenAnalysis.pdf.
46 Alastair O’Dell, PE Live: Regulation Needs to Catch Up With Hydrogen Development, Petroleum Econ. (June 24, 2020), https://www.petroleum-economist.com/articles/low-carbon-energy/energy-transition/2020/pe-live-regulation-needs-to-catch-up-with-hydrogen-development.
47 Hydrogen, Pipeline & Hazardous Materials Safety Admin. – Pipeline Safety Stakeholder Communications https://primis.phmsa.dot.gov/comm/hydrogen.htm (last visited Dec. 2020).