Operations and maintenance planning for community-scale, off-grid wave energy devices
CRC Press; Taylor & Francis Group
Marine Renewable Energy (MRE) has progressed towards commercialisation over the recent years but signifi-cant barriers still exist. This includes the currently high cost of energy, leaving MRE uncompetitive with re-spect to other more established renewable energy technologies. A significant proportion of this cost comes from Operation and Maintenance (O&M) activities. O&M activity can be reduced through the use of condi-tion-based maintenance scheduling. In offshore environments, the submerged location of most devices enables the use of underwater Acoustic Emission (AE), a new condition-monitoring technique. It combines acoustics (used for environmental monitoring of MRE influence on noise levels) with AE condition monitoring as used in air. This paper assesses the practicality of such an approach in complex ocean environments through detailed sound propagation modelling using the propagation model Bellhop in the Matlab toolbox AcTUP. Results show that acoustic propagation is very sensitive to variations in the shallow water environments considered. When concerning sensor placement, multiple-path interferences mean that the location of the measuring sen-sor(s) needs to be carefully considered, but might not cover all environmental variations over the several months necessary for accurate long-term monitoring. Associated to the shallow depths, these environmental variations also mean that some frequencies cannot be back-propagated easily, generally limiting access to the monitoring of Received Levels. The results presented here are the first steps toward optimizing AE sensor po-sitions and AE measuring strategies for arrays of devices.
The lead author would like to thank the academic supervisors of this IDCORE project for their contributions, advice and support. Similar thanks must go to the engineers involved in developing the Squid devices at Albatern Ltd. The author would also like to thank Wave Energy Scotland, the IDCORE programme and their funding bodies, in particular the ETP (Energy Technology Partnership), for their support. IDCORE is funded by the Energy Technology Partnership and the RCUK Energy Programme; Grant number EP/J500847/1.
Conference paper from RENEW 2016: 2nd International Conference on Renewable Energies Offshore, 2016-10-24, 2016-10-26, Lisbon, Portugal. This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.
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