As summer approaches, questions often resurface about gas storage levels and what they mean for Britain’s energy security. Storage is an important part of the gas system, but it is only one element of a much wider and more diverse supply mix. Focusing on storage in isolation can give a misleading picture of how Britain’s system operates.

Our 2026 Gas Summer Outlook provides a snapshot of how storage fits into Britain’s supply mix today, showing that it plays a flexible, supporting role alongside domestic production, imports from Norway and LNG from global markets. The Outlook is not, however, a definitive assessment of Britain’s longer‑term storage needs.  

Questions are often asked about the future role of storage but understanding that debate first requires a clear view of how gas storage actually works.

What is gas storage used for?

Great Britain’s gas storage facilities are designed primarily to provide flexibility, rather than to act as the main source of supply.

Storage helps the system respond to short‑term changes in demand and supply, for example:

• Daily or intra‑day swings in gas demand
• Variability in renewable electricity generation, where gas‑fired power stations step in to balance the system
• Short‑term supply disruptions or market tightness
• Shippers optimising their supply portfolio by utilising storage  

Stock levels change continuously and are driven by market behaviour. It is entirely normal for storage volumes to rise and fall at different points of the year.

Different types of gas storage – and why they matter

Britain’s gas system includes a mix of different storage site designs, each with different attributes. These include:

• Offshore depleted oil and gas fields typically operate seasonally, injecting during the summer and withdrawing over the winter.
• Onshore depleted oil and gas fields, these are seasonal in nature but shorter injection and withdrawal periods, at times will reinject during the winter to optimise operations.
• Onshore Salt Caverns many of these are very responsive, will switch between injection and withdrawal throughout the year to respond to market signals.

This combination allows Great Britain to respond to both gradual and rapid system changes, supporting operational resilience rather than simply maximising stored volumes.

How does this compare with Europe?

It is important to remember that Britain uses gas storage differently from many European countries.

Some European systems rely more heavily on large, long‑duration seasonal storage to meet winter demand. By contrast, Great Britain’s system has evolved to depend less on long‑term storage and more on a diverse, flexible supply mix, including:

• Strong UK Continental Shelf and Norwegian production
• Extensive interconnection with neighbouring markets
• Access to global LNG markets
• Storage technologies optimised for flexibility and rapid response

Because of these differences, simple comparisons between British and European storage levels do not tell the full story about how gas supply is secured or how the system operates.

A well supplied European system also benefits Great Britain. Strong storage positions across Europe reduce stress in the wider market and support resilience across interconnected gas networks.

Looking ahead: does Britain need more gas storage?

This is an important question, but it cannot be answered by looking at storage volumes alone.  

In our response to the government’s Gas System in Transition: Security of Supply consultation, National Gas was clear that storage will continue to play an important role as domestic gas production declines and reliance on imports increases.

But the question is not simply about how much gas is stored. What matters is how deliverable and flexible supply is during periods of system stress, and whether markets and infrastructure are set up to support that. Storage needs to be considered alongside LNG, interconnection and pipeline supply as part of a resilient, diverse system – supported by clear security‑of‑supply standards and market frameworks.

Explore our insights:

Gas Summer Outlook 2026: https://www.nationalgas.com/media/news/national-gas-publishes-2026-gas-summer-outlook 

Gas System in Transition: Security of Supply – our consultation response: https://www.nationalgas.com/media/news/national-gas-publishes-response-governments-gas-system-transition-security-supply