The January 2026 GB forecast brings a 5% average reduction in long-term battery revenues, driven primarily by lower wind buildout reducing Balancing Mechanism opportunities.

Following the latest Contracts for Difference auction results (AR6 and AR7), the wind buildout has been revised downward. A slower build of wind, including the indefinite delay to Hornsea 4, means GB now has approximately 14 GW less offshore wind capacity in the 2040s compared to the previous forecast.

Key updates:

• : 17% lower by 2040 (101 GW vs 120 GW previously). Lower wind reduces Balancing Mechanism volumes.