Maintenance and upgrade work completes at world’s largest tidal stream array

December 19, 2025, by Nadja Skopljak

Offshore works, which included turbine recovery, have been completed at MeyGen, described as the world’s largest tidal stream energy development, located in Scotland’s Pentland Firth.

UK-based tidal energy company Proteus Marine Renewables reported on December 18 that it had, together with project owner Ampeak Energy, completed works at the MeyGen tidal stream project which involved a series of turbine collection and redeployments, subsea cable works and turbine maintenance and upgrades.

Two of the three turbines (TTG 2 and TTG 4) were serviced offshore and returned to operation, while the third (TTG 1) was returned to Nigg for servicing and will be redeployed at a future date. No intervention was required on TTG 3, which has now accumulated seven years of operation, maintenance-free, the company reported.

“The operation that we have just completed is another world record. Five turbine interventions in three days, without leaving site, servicing two of those on deck and returning them into operation subsea. Our continued works like this at MeyGen validate the commercial viability of subsea founded turbines,” said Drew Blaxland, Proteus CEO.

“Our offshore services team works hand in hand with our turbine designers to ensure fit for purpose machines that can be handled safely and efficiently in high flow marine conditions. I am proud, not just of what has been achieved, but also of the professional manner in which it has been completed. Our low risk, repeatable and scalable methods help underpin tidal stream energy’s bankable investment proposition.”

Solstad’s Normand Vision offshore construction vessel (OCV) was involved in the activities.

MeyGen secured an agreement for lease for the Inner Sound tidal development site in October 2010 from The Crown Estate for 398 MW of installed tidal stream energy capacity to be consented in a phased approach. Phase 1 is an operational 6 MW demonstration array, covering four 1.5 MW turbines, which entered into the 25-year operational phase in April 2018.

The final turbine of the four for Phase 1 was deployed in December 2024, making the site fully operational and delivering 6 MW of power.

Phase 2 has been awarded a total of 59 MW with a target commissioning date of 2027, 2028, and 2029, respectively.