Government looks to review UK gas quality requirement to bolster LNG supply

THE UK government is reviewing a legal gas quality requirement in order to improve the country’s “attractiveness” to liquified natural gas (LNG) exporters abroad, a report has confirmed. 

Following an assessment of the security of the UK’s gas supply, the Department of Energy Security and Net Zero (DESNZ) warned that global competition for LNG has increased as a result of wars in the Middle East and Ukraine. 

Imported LNG accounted for 17% of the UK’s gas demand in 2025 – more than three-quarters of which came from the US – while Norwegian pipeline gas and domestic production each met around 40%. DESNZ said the UK’s “diverse range” of sources made the likelihood of supply interruptions “very low”. However, the report cautioned that the “attractiveness” of the UK as a market to export LNG could impact supply and import cost – which industry has long maintained is hindered by relatively strict gas quality requirements. 

In particular, the gas industry has argued that the range of permitted “Wobbe index” values, a measure of gas’s energy density, tends to increase LNG import costs as it often has to be ballasted with nitrogen to be brought underneath the upper limit. 

The Wobbe Index range is set by the Health and Safety Executive (HSE). In 2023, HSE reduced the lower limit but said there was not yet enough evidence that increasing the upper limit wouldn’t compromise safety. HSE has said it is “open” to a review provided sufficient evidence is supplied. 

DESNZ said it is now “working with HSE, Ofgem and industry to consider whether the current Wobbe index range remains appropriate”. 

LNG vs Norwegian gas

While DESNZ wants to lower LNG import costs, any increase in supply would be met with environmental concern owing to its relatively high embodied greenhouse gas emissions: producing a barrel of oil equivalent of LNG releases an average of 85 kgCO2e, more than ten times the emissions associated with Norwegian gas. 

The government took into account LNG’s high carbon footprint before approving production at the Jackdaw gas field last week. Developer Adura framed the decision as between low-carbon domestic gas and high-carbon LNG. While the government said that without Jackdaw lower carbon Norwegian supply could increase, the UK has a far greater surplus LNG capacity than for pipeline gas.