AWARDS FINALIST: Contact Energy and Syos Aerospace – Underwater Robotic Coating Measurement and Inspection System
Syos Aerospace and Contact Energy have delivered a world-first underwater robotic inspection system that is changing how hydroelectric penstocks are assessed and maintained.
The project enables precision coating measurement and visual inspection inside fully flooded steel penstocks, removing the need to drain the assets or send personnel into confined, steeply sloped tunnels.
The system was developed to solve a long-standing inspection challenge in hydroelectric generation.
Conventional inspections require isolating and dewatering each asset for manual inspection, typically meaning three to four days of downtime per penstock.
The robotic approach completes this in about three hours while keeping the infrastructure in service condition and fully flooded.
At the heart of the project is a compact, remotely operated vehicle designed for deployment through narrow stop-log slots from the dam walkway.
Design
The ROV was engineered to access openings with a maximum width of 320mm and operate at depths of up to 100 metres.
It combines 4K cameras, sonar systems, fibre-optic communications, and underwater data-processing capability, with a multi-jointed manipulator arm carrying a cleaning tool and ultrasonic coating measurement probe.
During deployment, the ultrasonic probe achieved coating thickness measurement accuracy of approximately ±3 micrometres underwater.
Measurements taken around the circumference of each penstock at the 12, 3, 6 and 9 o'clock positions, with five readings collected and averaged at each inspection point.
This creates repeatable, high-quality data that can be used to monitor coating performance and asset condition over time.
Deployment
Three hydroelectric penstocks were inspected using the robotic system. Each was completed through two robotic dives - the first for coating measurement and surface preparation, and the second for visual inspection of welds, joints, corrosion areas and general asset condition.
Real-time video and measurement data were transmitted to operators throughout the work, supporting informed decision-making without exposing people to confined-space or rope-access hazards.
The operational impact was significant. For a three-penstock power station, the method reduced total outage duration from nine to 12 days to about nine hours.
Eliminating dewatering, reducing labour requirements, and cutting lost generation time delivered safety, efficiency and cost benefits while improving the consistency and coverage of inspection data.
The project was originally conceived, engineered and delivered in 2025 by Bay Dynamics NZ in response to an underwater inspection challenge presented by Manawa Energy.
Following subsequent acquisitions, Bay Dynamics became part of Syos Aerospace and Manawa Energy became part of Contact Energy.
The completed deployment demonstrates how locally developed robotics can address critical infrastructure challenges in the energy sector and create a scalable model for safer, faster and more reliable hydro asset management. T
The annual Energy Excellence Awards will be held in Wellington on 19 August. The Innovation in Energy Award is sponsored by Fujitsu.