Triads (the three half-hours of highest GB system demand between November and February separated by 10 days) set the Embedded Export Tariff (EET) that distribution-connected batteries earn for net export. Triads fell across 3 different settlement periods in the 2025/26 season, rather than the historic norm of clustering at 17:30, and the GB battery fleet captured 49% of the available credit.

Key takeaways

• The three 2025/26 Triads landed at settlement periods 34, 35 and 37 (half-hours ending 17:00, 17:30 and 18:30). They fell on Thursday 20 November 2025, Monday 5 January 2026 and Tuesday 3 February 2026.
• The GB battery energy storage (BESS) fleet captured 49% of available Embedded Export Tariff (EET) revenue across the three Triad half-hours in 2025/26, up from 36% in 2024/25 and below 2023/24's 57%.
• Longer-duration batteries (rated above 1.5 hours) captured 70% of available EET, against 32% for shorter-duration batteries.

Where the three 2025/26 Triads landed

NESO confirmed the three 2025/26 Triads on 26 March 2026:

• Thursday 20 November 2025, settlement period 34, net system demand 40,976 MW
• Monday 5 January 2026, settlement period 35, net system demand 45,004 MW
• Tuesday 3 February 2026, settlement period 37, net system demand 41,227 MW