SSE Renewables has confirmed that hydroelectric and pumped storage units in Scotland have provisionally secured contracts for the delivery year, 2026/27, in the latest T-4 capacity auction in Great Britain.

Overall, SSE Renewables has secured provisional contracts for nearly 906MW of de-rated hydroelectricity generation and pumped storage capacity for the 12 months from 1 October 2026 to 30 September 2027.

This overall capacity will be delivered by a total of 26 units across 13 SSE Renewables-owned and operated hydro and pumped storage sites in the Scottish Highlands. This includes the company’s Sloy scheme (143MW), which is the largest conventional hydroelectric power station in the UK, as well as pumped storage capacity at Foyers (290MW).

"As the UK’s original source of renewable power, our Hydro portfolio has been a jewel in our crown since we first began generating power from water in the Scottish Highlands 80 years ago,” said Stephen Wheeler, SSE Renewables Managing Director. “Today, our hydro business continues to play an absolutely critical role in providing security of supply and in the transition to a Net Zero power system. That’s why I’m particularly pleased that our conventional hydro and pumped storage assets have secured provisional contracts for homegrown power supply in 2026/27.

“As we look to the next 80 years of Hydro generation, we are continuing to invest significantly in our Hydro business and we’ve set out a 10- year investment plan with £50m capex committed annually to enable a steady refurbishment programme of our existing fleet. We are also continuing to explore and progress new build opportunities in line with SSE’s Net Zero Acceleration Programme (NZAP) targets. The delivery of new flexible Hydro technology alongside investment in our existing Hydro performance will be vital to supporting a net zero future and ongoing energy security in the UK."

The provisional results of the latest T-4 capacity auction in Great Britain were published on Tuesday 21 February, with a total of 43GW in capacity contracts awarded to electricity generators at an auction clearing price of £63/kW.

The following hydroelectric and pumped storage units secured agreements for de-rated capacity:

Clachan ­– one unit for a total of 39.001MW

Clunie – three turbines registered as one unit for a total of 55.772MW

Deanie – two units for a total of 34.630MW

Errochty – three units for a total of 68.828MW

Fasnakyle – three units for a total of 63.752MW

Foyers – two units for a total of 290.005MW

Glenmoriston – two turbines registered as one unit for a total of 36.188MW

Inverawe – one unit for a total of 24.605MW

Lochay – two units for a total of 42.126MW

Luichart – two turbines registered as one unit for a total of 30.984MW

Rannoch – three units for a total of 43.743MW

Sloy – four units for a total of 143.330MW

Tummel – two units for a total of 33.997MW

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