1.29GW of battery storage wins contracts in UK’s T-4 Capacity Market auction

By Molly Lempriere
February 23, 2023
LinkedIn
Twitter
Reddit
Facebook
Email

The UK’s T-4 Capacity Market auction has cleared in its third round at a record high of £63 (US$75.9)/kW/year, more than double the previous record high price.

Of the ~46MW of pre-qualified capacity eligible for the 2026/27 auction, 46,031.692MW won contracts, representing 93.42%.

Significantly, the number of battery storage assets continued to grow. Of the 1.9GW of de-rated capacity to pre-qualify, 1.29GW secured contracts.

The T-4 is the mechanism by which the government contracts four years in advance for energy capacity to advance the UK’s energy security aims.

This article requires Premium SubscriptionBasic (FREE) Subscription

Try Premium for just $1

  • Full premium access for the first month at only $1
  • Converts to an annual rate after 30 days unless cancelled
  • Cancel anytime during the trial period

Premium Benefits

  • Expert industry analysis and interviews
  • Digital access to PV Tech Power journal
  • Exclusive event discounts

Or get the full Premium subscription right away

Or continue reading this article for free

This follows last year’s significant growth, which saw a ~800MW jump in capacity that pushed the contracts above 1GW. This split between 107 units, with more than 60% of this storage over two hours in duration.

Of this year’s 143 winning battery storage units, over 90% have contracts with a 15 year duration.

Renewables also surged, with 76.85MW of onshore wind, offshore wind and solar winning contracts. This is eight times the volume that won contracts last year, even if it remains a small segment of the overall capacity procured.

The T-4 results follow last week’s T-1 2023-24 Capacity Market auction, which cleared at its second highest price ever, with 5,782.777MW procured at a clearing price of £60/kW/y. That included 627MW of battery storage, with T-1 auctions contracting one year ahead.

Gas remained the big winner in the auction, growing to over 29GW, leading to questions around its use given Britain’s goal of a net zero electricity system by 2035.

To read the full version of this story, including a breakdown of all awarded Capacity Market Units (CMU) by generation type and capacity awarded, visit Current±.

13 October 2026
London, UK
Now in its second edition, the Summit provides a dedicated platform for UK & Ireland’s BESS community to share practical insights on performance, degradation, safety, market design and optimisation strategies. As storage deployment accelerates towards 2030 targets, attendees gain the tools needed to enhance returns and operate resilient, efficient assets.

Read Next

Premium
April 8, 2026
A panel at the 2026 US Energy Storage Summit in Dallas, Texas, discussed the “creative, innovative structures” developers are having to embrace to secure long-term revenues for energy storage projects.
April 7, 2026
FlexGen has acquired CES, which has to date commissioned more than 15GWh of battery energy storage system (BESS) projects.  
April 2, 2026
SSE Renewables, Matrix Renewables, Drax and Voltaria have all progressed large-scale BESS projects in the UK, all-in-all totalling 1.8GWh of new capacity.
Premium
April 1, 2026
What is the future for the grid-scale energy storage market in Italy, now that the dust has settled from the country’s long-awaited MACSE auction for BESS?
April 1, 2026
Developer-investor Hexa Energy Services has inaugurated what is thought to be Japan’s first operational battery storage project with a capacity market contract.