Variable Blends Operational

National Gas Transmission are working to decarbonise the gas grid by transporting hydrogen rather than natural gas. Blending hydrogen with natural gas provides a stepping stone towards this goal, fostering the hydrogen economy whilst also benefiting from up to 7% carbon savings from a respective 20% hydrogen blend.

The UK government supports blending up to 20% hydrogen by volume into the gas distribution networks and there are ongoing trials and assessments into proving the safety and technical feasibility of hydrogen blending across all networks and pressure tiers in the UK. It is anticipated that initially a low percentage hydrogen blend will be accepted onto the National Transmission System with this potentially increasing up to 20% hydrogen blends being accepted. This is largely due to few modifications being required to accommodate low hydrogen blend percentages on the NTS.

Additionally, NTS level hydrogen blending is likely to develop in phases of hydrogen blend percentage entering the network due to the hydrogen supply in the UK developing gradually over time. 2% hydrogen on the NTS equates to approximately 5TWh of hydrogen production, therefore increasing this percentage will require time.

Variability in the gas blends of the network is likely due to the production of hydrogen gradually increasing over time and injection of that hydrogen being geographically spread across the network. There is also potential that hydrogen supply can vary based on factors such as production methods, direct demand off takers, and availability. Therefore, it is important to understand the implications of blended hydrogen and natural gas at variable levels between 0-5% hydrogen and 0-20% hydrogen blend.

Hydrogen blend variability encompasses a range of factors that need to be carefully managed to ensure a successful transition to a hydrogen-integrated energy system. Understanding the impact to stakeholders such as current customers and interconnecting countries will be crucial to successfully transitioning to a blended network and identifying ways to mitigate any risks and make sure National Gas are aligned to support our stakeholders needs where possible. There is also a need to evidence the impacts and any associated changes to risks from a whole system management perspective, and to research the impact of blend variability on compressor train machinery assets.