The development of hydrogen pipeline networks is a critical component of the global transition to a hydrogen economy. However, the regulatory frameworks governing their construction and operation vary significantly across regions, creating challenges for large-scale deployment. This article examines key regulatory approaches in the European Union and the United States, identifies gaps in current standards, and explores proposals for harmonizing global policies to facilitate hydrogen pipeline infrastructure.

In the European Union, the Renewable Energy Directive II (RED II) provides a foundational framework for hydrogen pipeline development. RED II classifies hydrogen based on its carbon intensity, setting strict sustainability criteria for renewable hydrogen. Pipelines transporting hydrogen must comply with safety standards outlined in the European Agreement concerning the International Carriage of Dangerous Goods by Road (ADR) and the Pressure Equipment Directive (PED). The EU also mandates environmental impact assessments under the Environmental Impact Assessment Directive, requiring developers to evaluate risks such as leakage and land use changes. The European Hydrogen Backbone Initiative further encourages cross-border pipeline projects by proposing standardized technical specifications for hydrogen-compatible materials and compression systems.

The United States takes a more decentralized approach, with regulations primarily guided by the Department of Energy (DOE) and the Pipeline and Hazardous Materials Safety Administration (PHMSA). The DOE’s Hydrogen Program Plan emphasizes the need for retrofitting existing natural gas pipelines for hydrogen transport, while PHMSA enforces safety protocols under Title 49 of the Code of Federal Regulations. Unlike the EU, the U.S. lacks a unified federal policy on hydrogen pipelines, leading to variability in state-level permitting processes. California, for instance, imposes stringent environmental reviews under the California Environmental Quality Act, while Texas prioritizes rapid deployment with fewer regulatory hurdles.

Safety standards in both regions focus on mitigating hydrogen’s unique risks, such as embrittlement and high flammability. The EU’s ATEX Directive mandates explosion-proof equipment for pipelines in hazardous areas, while U.S. regulations prescribe maximum operating pressures and leak detection systems. However, gaps remain in addressing hydrogen’s long-term material compatibility, particularly for pipelines transitioning from natural gas service.

Environmental regulations also differ notably. The EU requires lifecycle emissions assessments for hydrogen pipelines, aligning with its broader climate goals. In contrast, U.S. guidelines lack explicit emissions thresholds for pipeline projects, though the National Environmental Policy Act (NEPA) mandates general environmental reviews. Neither region has fully standardized protocols for monitoring hydrogen leakage, a significant oversight given hydrogen’s indirect global warming potential.

Permitting processes present another challenge. EU member states must follow the Trans-European Networks for Energy (TEN-E) regulation, which streamlines approvals for cross-border pipelines. The U.S. relies on a patchwork of federal and state permits, often resulting in prolonged timelines. For example, securing right-of-way approvals from multiple landowners and agencies can delay projects by several years.

Proposals for harmonizing global standards are gaining traction. The International Partnership for Hydrogen and Fuel Cells in the Economy (IPHE) advocates for unified safety and material compatibility guidelines. Recommendations include adopting the EU’s material certification requirements globally and expanding the U.S. PHMSA framework to cover pure hydrogen pipelines explicitly. The International Energy Agency (IEA) suggests creating an international database of hydrogen pipeline incidents to improve risk modeling and regulatory best practices.

Another key proposal involves aligning environmental assessments. The IEA’s Global Hydrogen Review highlights the need for standardized metrics to quantify hydrogen leakage rates and their climate impacts. Integrating these metrics into existing frameworks like RED II and NEPA could ensure consistent environmental oversight.

Efforts to streamline permitting are also underway. The EU’s REPowerEU plan proposes fast-tracking hydrogen pipeline approvals by designating them as Projects of Common Interest (PCI). Similar approaches could be adopted in the U.S. through federal preemption of state-level permitting for interstate hydrogen pipelines.

Despite these advancements, critical gaps persist. Regulations for blending hydrogen into existing natural gas pipelines remain underdeveloped, with varying limits on permissible hydrogen concentrations. The EU permits up to 20% blending in some countries, while the U.S. lacks a uniform threshold. Additionally, liability frameworks for hydrogen pipeline failures are inconsistent, complicating insurance and investment decisions.

In conclusion, while the EU and U.S. have established foundational regulations for hydrogen pipelines, disparities in safety, environmental, and permitting standards hinder global deployment. Harmonizing material certifications, leakage monitoring, and permitting processes through international collaboration could accelerate infrastructure development. Policymakers must prioritize closing regulatory gaps to unlock the full potential of hydrogen pipelines in the energy transition.