The T-4 Capacity Market auction has cleared in its third round at a record high of £63/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.
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.
In total, 542 Capacity Market Units won contracts, from 251 companies and 162 parent companies.
| T-4 25-26 | T-4 26/27 | |
| Generation type | Total Capacity (MW) Procured | |
| Diesel | 359.62 | 357.46 |
| Distillate | 321.091 | 319.81 |
| DSR | 988.108 | 948.64 |
| Gas | 27,632.389 | 29,008.78 |
| Hydro | 842.437 | 814.2 |
| Interconnector | 6,966.2 | 6,854.36 |
| Nuclear | 989.814 | 964.04 |
| Offshore wind | 0 | 47.56 |
| Onshore wind | 9.599 | 20.73 |
| Solar | 0 | 8.56 |
| Storage – Battery | 1,093.567 | 1,290.61 |
| Storage – Pumped | 2,527.607 | 1,789.92 |
| Waste | 633.882 | 576.29 |
| Coal | 0 | 0 |
| Oil | 0 | 0 |
| Total | 42,364.314 | 43,000.96 |
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.
The T-4 results follows 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.
