Local transmission systems (LTSs) are the backbone of our energy network, delivering gas from offtakes to towns and cities across the country.
We manage around 3,100km of these high-pressure pipelines, which were originally designed to transport and store natural gas. But with Scotland and the UK aiming to meet legally-binding carbon reduction targets set by Holyrood and Westminster, a move away from fossil fuels towards greener alternatives, like hydrogen and biomethane, would allow for the most cost-effective, least disruptive transition to a low-carbon system.
Hydrogen offers the best opportunity to achieve the scale and volumes needed to deliver zero-carbon heat and transport, so our local transmission systems will have to adapt to carry pure hydrogen, hydrogen blends, and carbon dioxide (CO2). These gases have a different chemical makeup and behave differently from natural gas, so it’s important to assess how that impacts on the infrastructure.
We developed our LTS Futures project to investigate these issues from both a scientific and a regulatory perspective. The study found that 91% of our local transmission pipeline network is likely to be suitable for storing and transporting hydrogen. Its low-strength steel isn’t susceptible to hydrogen embrittlement: when a metal’s load-bearing capability is reduced due to hydrogen absorption, which could lead to cracking and ultimately failure of the pipeline. A more in-depth investigation of each pipeline and asset’s data records will help us understand its suitability and risk profile.
The project has already identified the high potential in repurposing the LTS network for carrying hydrogen and other green gases. Convening industry expertise is key, so in February 2020 we held a workshop, attended by the UK’s other gas distribution networks, National Grid Gas Transmission, the Health and Safety Executive, Department for BEIS, and other industry experts to foster close collaboration between stakeholders. The workshop shared the findings of the project’s first phase, identified gaps and developed a roadmap for future research. The workshop also resulted in the creation of a new cross-industry IGEM LTS Futures working group, which was established to identify and fill existing knowledge gaps and provide input into the new LTS standards for transporting hydrogen.
The biggest challenges on the decarbonisation journey are ahead of us, but our LTS Futures project’s first phase has shown that these vital components are up to the task of shaping our low-carbon energy system.