T-4 Capacity Auction Provisional Results for Delivery Year 2026-27

LCCC welcomes the results of the Capacity Market T-4 Auction for Delivery Year 2026-27. The T-4 ensures that security of supply is assured throughout 2026-27 with an additional 43GW capacity purchased at a clearing price of £63 /kW/year. 

This year’s T-4 has shown an increase in Battery Storage and Gas being supported by the Government’s Capacity Market scheme (administered by LCCC), as demonstrated in the chart below. Not only does additional investment in storage assure Great Britain’s security of supply, it also makes the electricity system more flexible and ready for the challenges of transitioning to Net Zero at the lowest possible cost to consumer.

Key outcomes:

  • Of the total 29GW of Gas, the auction resulted two big new build Combined Cycle Gas Turbine (CCGT), with a total capacity of 1.4GW 
  • The total derated capacity for Renewables reached 77MW
  • First time for Offshore Wind in T-4 auction
  • Existing capacity decreased by 1.7%.
  • New Build Generation decreased by 80%.
  • Proven DSR decreased by 34%.
  • Unproven DSR decreased by 7% 
  • Existing Interconnectors increased by 39%
  • New Build Interconnector decreased by 63%


Cm-T4 Auction


The graph below highlights the technology breakdown:

  • Increase in wind (Onshore and Offshore) is 59MW compared to last year.
  • The total derated wind capacity 68MW to non-derated which is 881MW.
  • 85MW decrease in Demand Side Response

CM T-4 Auction by technology

Find out more about the Capacity Market from LCCC’s data portal here