Route to cleaner greener gas

Northern Gas Networks (NGN) has completed the project as part of H21, in collaboration with fellow gas distribution networks Cadent, Scottish Gas Networks and Wales & West Utilities. It builds on the earlier H21 Leeds City Gate project, which established a hydrogen conversion of the gas grid was technically possible and economically viable.

Networks in the urban areas of Bournemouth, Cardiff, Edinburgh, Hull and Beverley, Liverpool, Teesside and West Yorkshire were modelled to explore how well a 100% hydrogen network could meet customer gas needs.

The recommendations from the report highlight the work involved in building the conversion strategy for each town, as well as utilisation of the existing mains replacement programme to prepare the networks with pipes sized ready for hydrogen and installing valves that can be used later to aid conversion.

The £440k project was funded by a Network Innovation Allowance (NIA) Ofgem grant. senior project manager at NGN, Mark Danter explains: “Hydrogen has a lower energy value than natural gas so it’s vital we understand the pressure and velocity issues which could arise and how we mitigate them to ensure a hydrogen gas supply meets consumer needs and is as safe and reliable as today’s natural gas network.”

Lorna Millington, future networks manager at Cadent added: “The towns gas conversion of the 1960s and 70s provides a blueprint for a successful transition. We have looked at how the gas network could be sectorised to cause minimum disruption to customers. It’s proposed that a conversion would be completed in the warmer months when gas demand is lower. Whilst isolating larger areas means the conversion is quicker, it may also lead to a longer disruption to service for customers so there is a balance to strike.”

NGN’s H21 project director, Tim Harwood added: “The vital evidence delivered by this project takes us another step closer to realising our vision of a 100% hydrogen network for the future. It’s reassuring that the extensive modelling has demonstrated that we can repurpose our gas assets to operate with hydrogen in a zero carbon future and, with only minor adaptations, still enjoy the resilience of today’s gas network.”

A copy of the report can be accessed at