The Department for Energy Security and Net Zero (DESNZ) has launched a new consultation exploring the potential for blending low-carbon H₂ into Great Britain’s gas transmission network.

Following previous consultations on H₂ blending into local distribution networks, the government is now seeking views on whether introducing H₂ at the transmission level—the high-pressure National Transmission System (NTS)—could offer strategic and economic value.

H₂ is seen as a key player in the UK’s push to reach net zero emissions by 2050. Blending low-carbon H₂ with natural gas could offer a transitional path, supporting early-stage H₂ production while reducing the carbon intensity of the existing gas network.

DESNZ is currently evaluating whether to enable blending of up to 2% H₂ by volume into the NTS. This small percentage could act as an “offtaker of last resort” for H₂ producers—providing a backup market when dedicated customers are not available.

The consultation outlines both the potential benefits and challenges. While H₂ blending could support the growth of the H₂ economy and help manage electricity system constraints, it also raises concerns for industrial users connected to the transmission system. Many of these users rely on stable, high-quality gas supplies, and even a 2% H₂ blend could affect equipment performance, increase costs, or require infrastructure upgrades.

Studies cited in the consultation show that most transmission-connected users could technically handle a 2% blend with minimal changes, though feasibility studies and equipment modifications may still be necessary. At higher blends (5% or 20%), the risks and costs escalate significantly.

The UK’s ability to blend H₂ is also influenced by developments in the EU. Under the EU H₂ and Decarbonized Gas Market Package, Member States can blend up to 2% H₂ by volume but are not required to do so. This creates potential interoperability issues with the UK’s gas interconnectors to Ireland, Belgium, and the Netherlands—especially if H₂ blends exceed that threshold.

DESNZ invites responses from a wide range of stakeholders including H₂ producers and users, gas transporters and shippers, storage operators, investors, and academics. The consultation is open to all and aims to inform future government policy, including whether blending should be enabled—and if so, how it might be implemented and supported.