SSE provisionally secures 5.66GW of capacity agreements in GB T-4 2027/28 auction

The provisional results of the GB T-4 2027/28 auction were published on Tuesday 27 February with a total of 42,831MW in capacity agreements awarded to capacity market units at an auction clearing price of £65/kW.

Across its Thermal and Renewables fleet, including Joint Venture interests, SSE has provisionally secured around 5,660MW of de-rated* capacity agreements.

SSE Thermal has provisionally secured agreements for 3,377MW of de-rated electricity generation capacity for the 12 months from 1 October 2027 to 30 September 2028.

This includes its Peterhead (1,081MW), Keadby 1 (692MW) and Medway (673MW) gas-fired power stations, as well as its smaller embedded plants at Burghfield (44MW) and Chickerell (44MW). An agreement was also secured at Marchwood (843MW), in which SSE owns a 50% stake and receives 100% of the economic benefit from capacity agreements.

In addition, Seabank Power Station, in which SSE holds a 50% stake and receives half of the economic benefit from capacity agreements, also secured an agreement for 1,130MW of de-rated capacity. Triton Power, which is jointly owned by SSE Thermal and Equinor, received contracts for its Saltend Power Station (1,007MW) and Indian Queens Power Station (132MW).

SSE Renewables has also secured provisional agreements for around 1,148MW of de-rated* capacity for the same delivery year, 2027/28. This capacity includes agreements for 1,074MW of de-rated hydro-electricity generation as well as 15-year agreements for three under construction battery storage sites at Monk Fryston (32MW), Ferrybridge (15MW) and Fiddler’s Ferry (15MW). The latter two sites were formerly coal-fired power stations, highlighting the potential for historic energy locations to be repurposed for a net zero future.

Catherine Raw, Managing Director of SSE Thermal, said: “Flexible power plays a crucial role in our electricity system and these agreements will allow our fleet to support security of supply by providing vital backup to renewables. Today’s auction falling short of its target capacity** reinforces the need to push forward with the next generation of flexible power generation to ensure we meet the looming capacity challenge while rising to the low-carbon opportunity. And as these auctions begin to increasingly shape what the power system will look like towards the end of the decade, it’s essential that they begin to deliver capacity at scale that is either low-carbon or capable of rapid decarbonisation.”

Stephen Wheeler, Managing Director of SSE Renewables, said: “This is an excellent result for our company and demonstrates how SSE is optimising value across our technologies to deliver homegrown renewable energy for British energy customers. Through this auction process our hydro power assets are continuing to demonstrate their value to Great Britain’s energy market some 80 years after they first brought electricity to the Scottish Highlands. Additionally, contract wins for new battery storage projects which we’re currently building in Northern England are supporting our accelerated growth plans through the delivery of our secure 1.2GW pipeline of utility scale solar and battery projects. In securing over 1.1GW of capacity, our mix of renewable technologies will play important and complementary roles in delivering increasing amounts of renewable energy generation and flexibility to help meet the UK’s climate action goals.”

The provisional results are subject to confirmation by the Secretary of State for Energy Security and Net Zero (DESNZ)

*A de-rating factor is applied to all capacity according to rules set by the UK Government.

** The published target capacity for the auction was 44GW with a total of 42.831GW in capacity agreements provisionally awarded.