Code amendments finalised for hybrid forecasting arrangement

We are introducing a new hybrid forecasting arrangement to improve the accuracy of intermittent generation forecasts and offers during winter 2025, benefiting market participants and consumers.

The new arrangement will provide a centralised forecast for each intermittent generating site – but intermittent generators can still use their own forecasts if they meet minimum performance standards.

The updated Code will operate alongside:

1. a contract with the centralised forecaster
2. guidance issued by the Authority for intermittent generators who wish to use their own forecasts.

Our decision on the final Code amendments follows consultation and includes some minor revisions reflecting feedback from submitters. The amendments will take effect on 1 July 2025.

Wind generation forecast analysis

Our analysis shows that forecasts for intermittent generation (like wind and solar) are often inaccurate. This affects reliability, security of supply and can increase costs for consumers.

We have published our analysis of forecast accuracy and bias from the five main wind generators over a three-year period. This will help set forecast performance standards under the new arrangement.

Next steps:

• Centralised forecaster procurement — We are selecting a provider for the centralised forecasting service.
• April 2025 workshops — We will hold workshops for intermittent generators, the forecaster and stakeholders to define information exchange requirements.
• Approval to use own forecasts — From mid-April 2025, intermittent generators can apply to use their own forecasts. We will publish final guidance on this process before then.
• Amendments in force from 1 July 2025 — Some intermittent generators have indicated they may struggle to make the necessary system changes by 1 July 2025. We will work with them to ensure they can achieve compliance as soon as possible. Those unable to meet the deadline will need to apply, and meet the requirements, for an exemption.