Our view of the National Transmission System’s capability to meet Great Britain’s gas needs

Great Britain’s energy system is undergoing a major transformation to achieve net zero which requires a change to the way we operate the system today. As the National Energy System Operator (NESO), we’re the independent, public corporation at the centre of the energy system, taking a whole system view to create a world where everyone has access to reliable, clean and affordable energy. 

Our role involves strategic network planning across electricity, gas, and new vectors such as hydrogen, adopting a holistic approach to decarbonising the whole energy system. We serve as GB’s gas network planner with specific obligations outlined in the gas planner licence. Our Gas Network Capability Needs Report (GNCNR) is our first publications under these new obligations and demonstrates how we’re taking a whole system approach to energy planning.

In the GNCNR, you can read our first independent view of the National Transmission System (NTS) and its capability to meet GB’s current and future network requirements. Our analysis indicates that the NTS has sufficient capability to continue operating safely.

How did we assess the National Transmission System?

The analysis of the physical capability of the NTS has been carried out using our Future Energy Scenarios (FES) 2024, with three net zero pathways and a Counterfactual.  

To determine the NTS capability needs, we looked at different supply and demand scenarios, taking into account factors like weather, day of the week, and historical data. We developed and consulted on our proposed methodology during the summer of 2024, and it reflects a similar methodology developed by National Gas to prepare its June 2024 Annual Network Capability Assessment Report (ANCAR). 

We’ve engaged with stakeholders during the development of this, and our Clean Power 2030 analysis, with feedback highlighting the need for the gas network to remain reliable and, vitally, gas network components – in particular its compressors – be available. The resilience of these gas network components has been considered in our analysis.  

Key findings 

• For everywhere except for South Wales, the probability of network constraints remains very low over the next ten years.
   
• Our analysis suggests that there will be an increased probability of constraints at the Milford Haven terminal in South Wales because of a potential increase in Liquefied Natural Gas (LNG) imports at low (summer) demand levels. We don’t anticipate that such constraints would impact National Gas’s ability to comply with its network safety or capacity obligations.
   
• Beyond 2035 the energy system is faced with increasing uncertainty because of the evolving dynamics of technology, policy, market forces and societal expectations. Due to the high degree of ambiguity and complexity, there is a further emphasis on the importance of strategic energy planning, and adopting a holistic approach to address net zero and security of supply in the most efficient, and economical way. 

What’s next?

• The findings within the report will be used by National Gas Transmission (NGT) to propose network reinforcement options in the Strategic Planning Options Proposal (SPOP). 
   
• We’ll then evaluate any proposed reinforcement options and create a Gas Options Advice Document (GOAD) by the end of 2025.
   
• This two-yearly cycle will allow for gas network capability needs to be identified and network reinforcement options to be developed and assessed. 

The GNCNR represents a stepping-stone towards building a Centralised Strategic Network Plan (CSNP), which will set out a coordinated, multi-vector approach to long-term network planning across GB. This will accelerate the development of the Government’s net zero ambitions. 

Following a commission from the Secretary of State for Energy Security and Net Zero, we’ve also published advice to explore how GB could achieve a Clean Power electricity system by 2030. This analysis has also assessed the ability for the gas system to provide the flexibility required to ensure adequate security of supply.

Conclusions 

We believe the NTS can safely operate over the next decade. However, an expected rise in LNG imports, especially at Milford Haven in South Wales, may increase the chance of network constraints. We ask National Gas to explore ways to manage these constraints in their upcoming SPOP.

Share your feedback

If you’d like to provide comments and feedback as we continue to analyse and provide strategic planning for the future of the gas transmission network, you can email us at: [email protected]. We’re committed to continue collaborating with stakeholders and customers to ensure that your views are reflected within our assessment.

View the full report