Online remote condition monitoring of tidal stream generators
Due to the predictable nature of tides, tidal energy is an environmentally attractive renewable energy source. However, considerable investment costs and expected costs of lifetime maintenance in hostile marine environments have hindered large-scale implementation. Operational availability has been shown to be as low as 25 per cent. This availability needs to be increased substantially if tidal energy harvesting devices are to become commercially viable. Integrated condition monitoring (CM) can provide a reliable tool for assessing the real-time condition of critical components of tidal systems, enabling cost-effective maintenance based on prediction rather than correction.
REMO aimed to create a novel CM system to help reduce the projected lifecycle maintenance costs of tidal stream energy by half and the generator downtime to a level comparable with wind turbines. The key objective of the project was to create a system capable of remotely and permanently monitoring the entire frequency spectrum of structural vibrations generated by all the rotating components of a tidal stream turbine, by combining a suite of accelerometer and acoustic emission sensors for the low and high frequency regime respectively. Underwater trials at TWI’s diving tank facilities in Middlesbrough validated the system. The developed prototype, now at the demonstration stage, assesses the structural and mechanical integrity of tidal systems to provide advance warning of the presence of faults and impending failures.
This project has shown that acoustic emission offers promising results and provides information about the damage level of the gearbox for tidal turbine gearbox monitoring.
This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement No 314839.
For more information, please visit the REMO website.