Energy regulator Ofgem has warned that Britain's gas supply capacity may fall short of peak demand on an extremely cold winter day, triggering a consultation to prevent a planned reduction in a crucial pipeline connecting the country to mainland Europe. The regulator assessed that under very rare stress conditions combining extreme weather with major equipment failure, peak gas demand during a severe cold snap could reach 408 million cubic metres per day, while available supply would only be 403 million cubic metres per day, leaving a shortfall of 5 million cubic metres.
Ofgem's scenario assumes not only an unusually cold snap pushing consumption to very high levels but also two major liquid natural gas terminals in Wales going offline simultaneously, removing 77 million cubic metres per day from the system. The regulator calculated peak demand based on figures since 2017, with the highest historical demand recorded at 417 million cubic metres per day during the Beast from the East in early 2018. Under normal circumstances with all supply sources functioning, Britain can rely on up to 505 million cubic metres per day flowing into the gas grid from North Sea production, Norwegian supplies, LNG terminals, storage facilities and pipeline connections to Belgium and the Netherlands.
The immediate concern stems from a planned 25 million cubic metres per day reduction in capacity on one pipeline, known as INT, which was scheduled for October this year. Ofgem and National Gas, the grid operator, are working to prevent this reduction through a compensation arrangement outlined in a consultation paper released on 20 October. If the reduction proceeds and the Welsh LNG terminals fail simultaneously, available supply would drop to 403 million cubic metres per day. However, if the pipeline reduction is prevented as intended, supplies should reach 428 million cubic metres per day even with the LNG terminals offline, sufficient to meet extreme demand scenarios.
The pipeline capacity reductions reflect a broader decline in Britain's gas interconnection capacity over the 2020s. One pipeline, BBL, has seen capacity fall from 45 million cubic metres per day in 2020 to 22 million cubic metres per day today, while another, INT, has dropped from 73 million cubic metres per day to 61 million cubic metres per day. Ofgem attributed tightening supply limits to declining European pipeline capacity and reduced production from the UK North Sea due to geological and commercial factors. The regulator described the scenario requiring action as very rare, as it demands both extreme weather and major system failure to occur simultaneously.
If a gas shortage of the magnitude outlined in Ofgem's stress test were to occur, National Gas has outlined potential emergency measures. These could include declaring a Network Gas Supply Emergency, an event that has never happened in British history. Such a declaration could lead to factories being ordered to reduce consumption and households being asked to use less gas, with household supplies potentially being managed as a last resort. Ofgem's consultation represents a medium-term solution but does not remove the need for further government-led measures to address longer-term supply pressures.
For consumers, businesses and investors, Ofgem's assessment means there is a small but identified risk that Britain could face gas rationing during an extreme winter if multiple supply disruptions occur simultaneously, though preventive action is being taken to reduce this possibility.