Statutory security of supply report: 2025

DESNZ and Ofgem’s joint annual Statutory Security of Supply Report provides an assessment of the availability of secure, affordable electricity, gas and oil for meeting the needs of consumers.

Executive summary

The Statutory Security of Supply Report 2025 concludes that GB is expected to have the ability to access and secure sufficient supplies of electricity and gas to meet consumers’ demands over the short and long-term (this assessment covers the next four calendar years, as required by legislation). GB has also continued to maintain good access to oil supplies. Government will continue to closely monitor security of supply.

Electricity security of supply

GB has demonstrated consistent success in ensuring secure electricity supplies and is expected to continue this trend in the future. NESO forecasts sufficient electricity capacity to meet this winter’s demand, with a derated margin of 6.1GW (10.0%) of the Average Cold Spell (ACS) peak demand for this winter. This is an increase from 5.2GW (8.8% of peak demand) last winter and is the highest predicted margin since 2019.

The UK benefits from a diverse electricity mix including gas generation, renewables, nuclear and interconnector imports. This reduces our dependence on one generation source and helps ensure security of supply in a range of conditions. The Capacity Market (CM) is GB’s key mechanism for ensuring there continues to be sufficient electricity capacity margin to meet peak demand. The required electricity capacity needed to ensure security of supply over the medium term has mostly been procured via four-year ahead auctions, with the most recent auction in 2025 having been for the T-4 delivery year of 2028/29, while any remainder is procured through future ‘top up’ auctions held in the year before delivery. While most of this capacity comes from existing units, new build projects which can enter multi-year CM agreements have also been successful. This includes a pipeline of electricity storage and interconnector projects.

Gas security of supply

Natural gas (‘gas’) remains a vital component of Great Britain’s energy mix, continuing to play a key role in heating, industry, and power generation. GB has access to a diverse range of gas supply sources, with domestic gas from the UK Continental Shelf, imported gas via the Norwegian Continental Shelf, the interconnectors, and LNG from various global supply routes.

Although gas reserves from the UK Continental Shelf are continuing to naturally deplete for geological reasons, government is accelerating the decarbonisation transition which will reduce our exposure to fossil fuels. Over the next four years specifically, we expect this changing supply mix to coincide with a robust, oversupplied global LNG market, as detailed in this report.

The role of gas is expected to continue to evolve in the longer-term from providing base load supply to playing a key part in ensuring system flexibility. As such, we are committed to protecting gas security of supply as long as it is required, with a clear plan:

First, government will accelerate efforts to decarbonise and electrify the economy, which will over time reduce our gas demand and therefore our exposure to fossil fuels.

Second, we will continue to work with the gas industry and market to maintain security of supply as supply and demand patterns change. DESNZ is addressing this through the Gas System in Transition: Security of Supply consultation published in November, the aim of which is to ensure sufficient and resilient gas infrastructure and to understand how we can best provide insurance for low-probability, high-stress scenarios. It is the first step in government’s programme of work to manage the challenges facing the gas sector and ensure security of supply in the long term.

Third, DESNZ and Ofgem will continue to work with the gas system operator, National Gas, who manage the system with a variety of balancing tools on a day-to-day basis, and with NESO, who will continue to provide advice through its annual gas security of supply assessments. Assessments from National Gas and NESO have informed this report.

Oil security of supply

In 2024, UK demand for oil products continued to recover following the lifting of COVID-19 travel restrictions. Total product demand increased by 2.0% compared to 2023, with jet fuel experiencing the most significant growth, rising by 7.9% as international air travel approached pre-pandemic levels.

Domestic supply in the UK’s production of crude oil and natural gas liquids fell to 30.4 million tonnes, aligning with the long-term natural decline of the mature North Sea basin. Refinery output also remained subdued, with total production of oil products at 50.8 million tonnes.

To meet rising demand and compensate for declining domestic production, the UK’s net primary oil imports increased by 11.7% in 2024. Following the implementation of sanctions on Russian oil imports in response to the 2022 invasion of Ukraine, the UK expanded its network of trading partners. The UK continued this in 2024, diversifying supply to further enhance energy security.

Despite the transition of the Grangemouth refinery to an import terminal and the cessation of refining operations at Prax Lindsey Oil Refinery, the UK remains relatively well-positioned in terms of oil supply security, maintaining strong self-sufficiency in petrol and meeting demand for other oils through trade with both established and new trading partners.

Read the full report below.