The Role of Accelerated Testing in Reliability Prediction

Abstract

The transition from the early stages of marine renewable energy (MRE) device development towards pre-commercial status involves rigorous design validation before full-scale testing. The main aim of Technology Readiness Levels 4-6 is to prove that the concept can deliver the required power production performance and also that a level of system reliability is achieved to ensure sufficient availability. Both of these metrics are crucial to obtaining competitive levelised cost of energy. The current state of the MRE sector means that reliability data is sparse or commercially sensitive. Device developers are therefore forced to base reliability predictions on physical testing, detailed numerical analysis or in the absence of these, generic (and potentially unsuitable) failure rate databases. Generic data will only provide a crude estimate of component or subsystem reliability unless modified to suit the application. More accurate estimates of component and subsystem reliability are possible through accelerated testing. As part of the DTOcean (Optimal Design Tools for Ocean Energy Arrays) project, results from physical tests involving synthetic ropes and shackles are used to demonstrate how quantitative accelerated testing can be used to bridge the gap between generic failure rates and those which are applicable to MRE mooring applications.