This year’s Gas Winter Outlook analysis indicates that Great Britain has sufficient supply capability to meet peak demand, maintaining a positive supply margin.

The assessment further indicates that Britain will continue to have a strong, diverse range of supplies from UK Continental Shelf (UKCS) and Norway, and flexible supply options from LNG, imports from continental Europe and domestic storage.

Key insights from the report include:

• For winter 2025/26, Great Britain has sufficient supply to meet peak demand, maintaining a positive supply margin, even accounting for unforeseen network outage scenarios.
• Gas demand for winter 2025/26 is forecast to be 3% lower than last year, mainly due to reduced demand for power.
• Overall gas demand for power is expected to fall by 18%. This follows an 18% increase last winter driven by colder weather, reduced wind generation, and the closure of Britain’s last remaining coal plant.
• While overall gas demand for power is forecast to fall, high peak demand days are still expected. The half-hourly peak last winter reached a record 28GW, with gas supplying up to 73% of electricity on 10 December 2024.
• National Gas is confident the market will perform as expected, although it is constantly monitoring for any potential disruption that may have an impact on Great Britain.
• Margins for this winter are tighter than in the previous 4 years, but similar to those observed in 2019/20 and 2020/21. This is largely due to the continued decline in UKCS supply (down 0.9 bcm compared to last winter) and some reductions to storage and interconnector capacities.

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

“As we head into winter, we remain confident in the resilience of our gas system and our ability to meet Britain’s energy needs during periods of peak demand.

“The energy landscape is evolving, with a growing reliance on imports and the continued decline of UK Continental Shelf supplies. Meeting these challenges requires a coordinated, forward-looking approach, and we’re working closely with government, industry, and regulators to develop the right solutions that safeguard security of supply for the future.

“National Gas is the backbone of Britain’s energy system, and we are constantly using every available tool to ensure we’re prepared for this Winter and beyond. Through real-time monitoring and strategic planning, we’re ensuring the gas system remains reliable, resilient and responsive to meet Britain’s energy needs.”

The report demonstrates that gas demand for power continues to show significant volatility, influenced by weather conditions and renewable generation. Although a decrease is projected compared to last winter, periods of high demand are still expected during peaks, especially when renewable output is low. This highlights the ongoing role of gas in maintaining system resilience and supporting power station operations during periods of low renewable availability.

Ian Radley, Chief Commercial Officer at National Gas, said:

“Ensuring the resilience and reliability of Britain’s gas system for the coming winter and beyond is always our top priority.

“This Winter, we expect continued volatility in gas demand for power, with significant swings driven by weather patterns and renewable generation. Such unpredictability highlights the vital role of gas as a strategic backup, stepping in to balance the system during periods of low renewable output.

“As we look to the future, investment will be pivotal in maintaining reliability and ensuring our gas infrastructure is ready for the demands of tomorrow. Our focus is not just on managing today’s challenges, but on building a gas system that is resilient, and able to support Britain’s energy needs whatever the weather brings.”

National Gas remains committed to securing Britain’s energy, keeping homes warm, businesses running, and industries fuelled. By working collaboratively with partners across the sector and investing in the strength of our network, we are ensuring that Great Britain is well-prepared for this winter and beyond.

During winter, the National Transmission System (NTS) transports up to three times the energy delivered by the electricity grid. Thirty-three power stations are currently connected to the NTS, providing a total capacity of 30GW. Three additional stations are expected to connect this year, adding a further 1GW of capacity.

You can read the full report here.
There is also a summary report available here and you can download the data workbook here.