Updating the Offshore Transmission Cost Assessment Guidance

Consultation description

Our consultation seeks views on an updated draft of the Offshore Transmission Cost Assessment Guidance (CAG). The guidance sets out our updated approach to assessing the economic and efficient costs of offshore transmission assets, before these are transferred to an Offshore Transmission Owner (OFTO). 

This update reflects insights from stakeholder engagement and Ofgem’s experience to date, setting out a more defined evidence-based framework for Offshore Transmission Cost Assessment.

Following this consultation, Ofgem will review responses, refine the draft of the CAG where appropriate, and publish the final updated version later in 2026.

Who should respond

We welcome responses from anyone with an interest in offshore transmission. We particularly encourage feedback from offshore generation developers and OFTOs.

How to respond

Submit your response by 7 September 2026 by emailing offshoretransmission@ofgem.gov.uk.