Data-driven cable monitoring extended at world’s largest tidal array

UK-based climate tech start-up Indeximate has secured a three-year extension to provide cable condition monitoring for SAE Renewables’ MeyGen tidal array in Caithness, Scotland. 

The contract, active since March 2024, includes an annual subscription to the company’s Scattersphere system, used to monitor cable and environmental conditions across all four turbines. It also covers the storage of distributed acoustic sensing (DAS) data collected during the monitoring period.

According to Indeximate, MeyGen employs both DAS and distributed temperature sensing (DTS) to track the health of its subsea cables, which are deployed in challenging conditions: tidal races, surface deployed on a rocky seabed.

In early 2024, MeyGen partnered with Indeximate to extract key findings from the DAS data. The system identified high-risk locations along turbine connectors and reported on vibration, abrasion, fatigue, and cable pinning or skipping. 

According to the company, monitoring revealed how these risks evolve in line with lunar cycles and seasonal storms, enabling the operator to revise its inspection strategy and target critical sections of the export cable infrastructure.

“MeyGen generates predictable renewable electricity by harnessing the natural cycle of the tides. Operating in the Inner Sound of the Pentland Firth, however, means working in one of the world’s most extreme marine environments, where tidal currents can exceed 10 knots. This powerful tidal resource offers immense potential for clean energy generation, but also presents significant operational challenges,” said Fraser Johnson, Operations & Maintenance Manager at MeyGen PLC.

“Our subsea export cables are engineered to endure the harsh conditions, but we remain highly aware of their exposure to turbulent flows and the seabed’s scouring effects. To address this, we’ve deployed Distributed Acoustic Sensing (DAS) technology along the cable routes supported by Indeximate to provide 24/7/365 monitoring services. This innovative monitoring allows us to assess asset risk with such precision that we are able to self-insure the cables, thanks to our detailed understanding of their condition.”

MeyGen operates the world’s largest tidal-stream array, located in the Inner Sound of the Pentland Firth between mainland Scotland and the island of Stroma. It has generated more than 75 GWh of electricity from 1.5 MW turbines and has consistently achieved system availability above 95%.

“This monitoring initiative is a key element of our Tidal Asset Revenue Optimisation strategy. By implementing a data-driven, proactive asset management approach, we ensure continuous condition monitoring and enable timely, informed maintenance decisions—intervening before issues arise to enhance reliability and reduce downtime,” Johnson added.

The site’s export cables, laid directly onto bedrock in high-flow zones, are now continuously monitored using DAS supported by Indeximate.

“We are delighted that MeyGen has chosen to renew and extend their subscription. We’ve managed to illustrate in a short time the critical at-risk regions of MeyGen’s cables supporting our mission of preventing cable failure. The long-term subscription demonstrates that our work is providing much needed value in assessing cable health and maintenance efforts,” said Chris Minto, Director at Indeximate.

In April, UK-based tidal energy company Proteus Marine Renewables (PMR) confirmed that the AR1500 tidal turbine deployed at the MeyGen site in Scotland exported 372 MWh of electricity in March 2025, marking the turbine’s highest monthly output since it began operations in 2017.