Seagreen offshore O&M services for SSE Renewables

Ventus Energy delivered flexible high-voltage support and maintenance services for SSE Renewables to help maximise uptime and ensure the long-term reliability of Seagreen’s critical transmission infrastructure

Project overview

Client: SSE Renewables
Services: Interim OFTO primary and secondary inspection and maintenance services
Location: North Sea, Angus coastline, Scotland
Project lead
Client contact: Josh Graham, Technical Project Manager
Duration: 1 - 1.5 years
Completed: 2025

The brief

Following installation of Seagreen’s OFTO asset, SSE Renewables required an experienced high voltage partner to provide support with interim inspection and maintenance services during the asset’s early operational phase. Ventus Energy was engaged to assist, marking the third project delivered in partnership with SSE Renewables, having previously supported the operator’s Beatrice and Greater Gabbard wind farms since 2021.

Challenges

As a newly installed OFTO asset, Seagreen presented typical early-life and commissioning-related challenges, including:

Installation-related defects across both primary and secondary systems
Issues identified during initial inspection and maintenance activities
Extended programme timelines, requiring Ventus to maintain a continued on-site presence
The requirement to bring substations up to a high standard of operational readiness ahead of asset transfer

Solution

With several challenges broadening the original project scope, Ventus adapted its approach to support both immediate maintenance requirements and the project’s extended timeline, including:

Deploying a combination of in-house engineers and specialist subcontractors
Adopting a diagnostics-led approach using thermal imaging, partial discharge analysis and oil diagnostics
Carrying out a major planned outage to enable intrusive inspections and full maintenance of high voltage assets

Outcome

Ventus delivered a flexible and responsive service, adapting to programme changes while maintaining a consistent on-site presence and high-standard of delivery. As the project evolved, support extended beyond the original inspection and maintenance scope to include safety from the system, utilising SSE authorised personnel where required. Drawing on the wider RTS Wind Group capability, the team was also able to support with balance of plant activities, resulting in the project benefiting from a more joined-up approach across the full asset.

The outcome of this combined approach was improved asset reliability, reduced risk ahead of transfer and the delivery of a clear and comprehensive service history, ultimately supporting a smooth and de-risked OFTO handover.

“It was a pleasure to support Seagreen with the interim offshore OFTO services. This feedback reflects the strength of our operational team and our ability to draw on expertise across the RTS Group to deliver flexible, turnkey support while maintaining availability and minimising disruption to operations.”

Alastair Symington

Head of Operations at Ventus Energy

"Ventus provided high‑quality support throughout the Seagreen OFTO O&M works – supporting Seagreen Wind Energy Limited, a joint venture between SSE Renewables, TotalEnergies and PTTEP – successfully delivering a large and complex scope during a challenging period when the site was still under construction. They worked collaboratively with us to build a full maintenance regime from limited documentation and carried out all planned works to a high standard, bringing in specialist subcontractors where needed. Their ability to adapt and deliver reliably added real value to the project.”

Josh Graham

Technical Project Manager at SSE Renewables

Benefits

Alongside delivery support and access to RTS Wind Group capability, a key benefit of working with Ventus was the ongoing technical guidance throughout the project, helping SSE Renewables make informed decisions around asset condition, maintenance strategy and operational readiness.

Through diagnostics and inspection findings, the team identified emerging issues, recommended corrective actions and gave the client clear visibility of asset condition ahead of transfer, strengthening confidence in the asset’s longer-term performance.