Mitigations to protect future security of gas supply identified

We've published our first annual Gas Security of Supply Assessment. Through our new responsibility as Great Britain’s Gas System Planner, we have a licence obligation to assess gas supply security at the five- and ten-year-ahead horizons.

In this Assessment, we've analysed the availability, reliability and deliverability of gas volumes needed to meet a range of future demand scenarios for Great Britain’s National Gas transmission network. The Assessment focuses on winters 2030/31 and 2035/36 and considers the intervening years, to provide a clearer view of gas supply security across this period.

The Assessment shows that Britain is expected to continue benefiting from a diverse range of gas supply sources in the 2030s. These sources include the United Kingdom Continental Shelf, Norwegian Continental Shelf, Liquefied Natural Gas, pipeline imports from Europe, gas storage and biomethane. The relative contribution of these sources will evolve over time, primarily driven by the long-term natural decline of UKCS production – a trend evident since the early 2000s.

The Assessment shows that gas supply is expected to be sufficient to meet demand under seasonal normal weather conditions. When testing against a range of 1-in-20-year peak demand scenarios for 2030/31 to 2035/36, the analysis identifies an emerging risk to GB gas supply security.

In scenarios where all gas supply and network infrastructure are operational (intact), this risk is evident only where decarbonisation is slowest – where peak gas demand is expected to remain close to, or even exceed, current expectations. However, in the unlikely event of the loss of the single largest piece of gas infrastructure (the N-1 test), gas supply falls short of demand expectations for all pathways in 2030/31. In 2035/36, this shortfall is apparent only in pathways where gas demand remains high due to slower progress towards decarbonisation.

Given the risks identified, this Assessment shows that a combination of measures will likely be required to mitigate emerging security of supply risks. The mitigations identified in this Assessment, together with the consultation announced by government – which will seek views on the need for policy action and potential interventions – provide a suite of options capable of addressing these risks.

Mitigation options identified include reducing peak day gas demand through decarbonisation, maximising peak day supply from existing infrastructure, and developing new gas supply infrastructure. Delivering any action will require coordinated effort across the four organisations responsible for gas supply security – NESO, government, Ofgem and National Gas – to ensure the timely delivery of the most effective options for GB consumers.

Dr Deborah Petterson, Director of Resilience and Emergency Management, National Energy System Operator said:

“Our analysis shows that Great Britain will continue to benefit from a diverse range of gas supply sources in the 2030s, and that gas supply is expected to be sufficient to meet demand under normal weather conditions.

“We have, however, identified an emerging risk to gas supply security where decarbonisation is slowest or in the unlikely event of the loss of the single largest piece of gas infrastructure on the system.

“By conducting this analysis, we are able to identify emerging risks early and, crucially, in time for mitigations to be put in place. Our assessment shows that a combination of measures will likely be required to mitigate those emerging risks and we will work with government, Ofgem and National Gas Transmission to ensure the timely delivery of the most effective options for consumers.”

Director of Energy Resilience and Systems, Glenn Bryn-Jacobsen, at National Gas said:

“National Gas welcomes the publication of NESO’s Gas Security of Supply Assessment and was pleased to support its development.”

“Our latest Winter Outlook shows the short-term outlook is robust, even in the unlikely event of major infrastructure disruption. Looking ahead, we recognise the potential longer-term challenges this Assessment highlights, which align with our own analysis. We have been working closely with government, NESO, and Ofgem for some time to understand these challenges more fully, and we welcome the Government’s consultation as an opportunity to collaboratively develop the right solutions and take the necessary action.”

“Gas remains a critical component of Britain’s energy security - keeping homes warm, powering industry, and supporting electricity generation during periods of peak demand and low renewable output. In considering potential solutions, it is essential to look at both the gas supply landscape and the investment required in network infrastructure.”

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