UK reactor extensions to cut gas demand, help swing to exports from 2028

Lifetime extensions for two nuclear power plants in the UK to 2030 will reduce gas-fired output and the need for power imports, with Great Britain potentially net exporting from winter 2028, an analysis by S&P Global Energy CERA showed.

EDF Energy and Centrica announced July 22 an extension on the lifespan of the 1.1-gigawatt Heysham-1 and 1.2-GW Hartlepool nuclear plants to March 2030, having already granted one-year extensions from a planned March 2026 closure date twice.

The reactors are set to generate about 28 terrawatt-hours in the extra two years if kept online. EDF estimates that this could avoid the import of about 25 LNG cargoes, or 20% of UK LNG imports in 2025.

"Our forecast had assumed that one unit would receive a further one-year lifetime extension to March 2029, while the other would cease generation in March 2028," analysts at CERA said in a report July 23.

An extended lifetime scenario, which assumes both units stay online, lifts GB nuclear generation by about 4.6 TWh for April-December 2028, driving a GBP2/megawatt-hours reduction in GB power prices relative to our base case, the analysts said in the report.

Platts, part of S&P Global Energy, assessed UK summer 2028 baseload power at GBP66.45/MWh on July 24, compared to GBP89/MWh for summer 2027, partly due to the removal of the CPS carbon tax at GBP18/mt.

Winter power prices are also expected to fall amid rising wind capacity and lower gas prices further out, with winter 2026 assessed at GBP127.65/MWh July 24, compared with winter 2028 at GBP73.60/MWh, Platts data showed.

Higher nuclear generation displaces UK gas generation and power imports by 400 MW and 300 MW, respectively, for the remainder of 2028, CERA said.

"Twinned with strong offshore wind additions, and the removal of the Carbon Price Support levy from April 2028, this sees GB exporting at an average of 0.6 GW in Q4-2028," CERA's UK power analyst Calum Andrews said, noting that wider implications beyond 2028 will be modeled this week.

Multiple extensions since 2024

Three major lifespan extensions since December 2024 boosted UK nuclear output by about 90 TWh between now and March 2030 at the four AGR sites, which were scheduled to close in March 2026 (Heysham-1, Hartlepool) and March 2028 (Heysham-2, Torness).

First, in December 2024, EDF and Centrica extended the lifespan of Heysham-1 and Hartlepool by one year to 2027, which was extended to 2028 last September.

Heysham 2 and Torness were extended two years until March 2030.

The lifespan extensions announced in December 2024 and September 2025 are expected to generate 60 TWh, EDF said, noting that the additional volumes would displace about 12 Bcm of natural gas.

EDF plans to invest 1.3 billion pounds by 2027 to safely extend operating lifetimes, it said back in 2024.

In addition, EDF and Centrica also reached a deal with the UK government to extend the life of the 1.2-GW Sizewell B by 20 years, underpinned by a 20-year contract for difference (CFD) at GBP70.50/MWh in 2025 prices.

UK nuclear reactor lifespan extensions:

*estimated by S&P Global Energy based on historic load factors, adj for EDF's combined estimates in Dec 2024 (45 TWh), Sept 2025 (15 TWh) and July 2026 (28 TWh)

Source: EDF Energy, S&P Global Energy