As the UK moves into a period of transformed energy production and use, several concerns need addressing to enable hydrogen to play a vital role in our energy future. At present, hydrogen plays a key part in the chemical industry as an important feedstock.
Following the release of the UK Hydrogen Strategy and the outcome of the climate summit, the hydrogen market will likely expand further. With stricter carbon reduction commitments, policymakers and pipeline operators need to significantly consider what is required to make hydrogen a bigger part of the clean energy mix in the UK.
From a practical perspective, the National Grid has developed its offline hydrogen research facility with several partners exploring the feasibility of producing, transporting and supplying customers with a fuel composition ranging from 2% to 100% hydrogen. Initial studies suggest that around 20% hydrogen mix would work with existing systems, but as hydrogen has a much higher volume than natural gas, a 20% mix would only correspond to an approximately 6% reduction in conventional fuel use.
In the long term, relying on the existing NTS volume will probably not enable hydrogen fuel to be scaled to the level required to meet emission reduction targets without introducing other non-pipeline power sources. If the long-term goal is to increase the piped gas mix to 100%, it hasn’t been defined how this will be achieved without considerable new infrastructure.
Repurposing the UK gas supply network to meet the needs of hydrogen will require tackling some challenges within the existing system. The majority of pipeline infrastructure making up the UK NTS consists of steel and was originally installed between 1940 and 1970. High hydrogen concentrations can accelerate the degradation by making pipes more brittle and vulnerable to cracking.
The added concerns of hydrogen’s low density, increased risk of leakage and high flammability make transportation and storage an additional challenge in terms of transmission and liability. This is a major factor that needs to be considered by pipeline operators.
Other factors need to be considered before altering or upgrading existing pipeline systems for hydrogen, such as checking the land rights to ensure the transmission of hydrogen is allowed. Producing and transporting hydrogen will likely require additional pipelines than the UK currently has. Determining the type of hydrogen, whether it is green, grey or blue will define what sort of infrastructure is required.
While ideally, the UK would move straight into green hydrogen, the majority of hydrogen production continues to be ‘grey hydrogen’, made with reforming steam methane from natural gas, which produces hydrogen and CO2 and requires additional pipelines. If grey hydrogen is combined with carbon-capturing technology, the CO2 can be transported away, which requires further infrastructure.
Aside from solving concerns with funding the construction of a new pipeline or finding the necessary talent, it’s fair to question why operators can’t construct new pipelines. The main reason is due to land and planning law requirements. Many factors need consideration with large scale infrastructure projects. Such projects must meet the public interest criterion and applications must be submitted to the Planning Inspectorate (PINS) for evaluation by the Secretary of State for Business, Energy and Industrial Strategy.
Given the dense population of the UK, any major upgrade to the energy distribution network will require considerable new infrastructure. Given that the process to acquire new rights has a lead time of around two years, it’s likely that the Government will shift its focus towards the idea of a faster approval of reusing existing assets.