Executive Summary

• The T-4 2028/29 Capacity Market auction has 48.7 GW of prequalified de-rated capacity, exceeding the target by just 4.7 GW—one of the lowest margins in recent years.
• Battery prequalification surged to 14 GW, making it the second-largest technology type in the auction, but 88% of de-rated battery capacity remains conditionally prequalified.
• Historic trends suggest the auction could clear between £63/kW and £65/kW, as tight margins and lower-than-expected final capacity could push prices higher.

Subscribers to Modo Energy’s Research will also find out:

• How new de-rating factor methodology has significantly increased battery capacity in the auction compared to previous years.
• Why the proportion of prequalified battery capacity that actually enters the auction may be much lower than other technologies.
• How upcoming February updates will confirm capacity targets and determine whether price expectations hold.

To get full access to Modo Energy’s Research, book a call with a member of the team today.

Introduction

On 11 December 2024, the Electricity Market Reform (EMR) Delivery Body published the first Capacity Market Register for the T-4 2028/29. The register includes the details of all the units that prequalified, opted out, or were rejected ahead of the latest auction.

The past two auctions cleared at record-high prices. So how far are the early conditions of this auction comparable?

48.7 GW of de-rated capacity has prequalified for the T-4 2028/29 Capacity Market auction