System Approach to Reliability Engineering - Case: Wave Energy Converter

Abstract

Wave power is a promising technology for producing renewable energy. Several types of wave energy converters (WECs) have recently been developed and introduced as technical solutions for capturing the energy of ocean waves. One of the WEC types is an Oscillating Wave Surge Converter (OWSC) that extracts energy from wave surges and the movement of water within them. Reliable operation and high system availability of WECs are key aspects to achieve the levelized cost of energy (LCOE) targets. Systematic reliability engineering methods can offer valuable support for the design and evaluation of highly automated multi-technical WEC systems. Analytical and simulation-based methods such as Failure Mode, Effects and Criticality Analysis (FMECA), Reliability Block Diagrams (RBDs) and Life Cycle Cost (LCC) calculations can be utilized in from early conceptual design phase. The system approach aims to guide the work to right system hierarchy level and to enable the use of available but partly uncertain information for system models, analyses and simulations. The research on reliability engineering methodology in VTT is related to concept development and system design of an OWSC and especially its power take of system (PTO) in an ongoing EU funded research project 'MegaRoller'. Our results confirm that reliabilityengineering efforts should be considered as an interconnected and iterative process, and the system approach helps to look at things at the appropriate level and accuracy.

Reliability Modelling and Analysis of the Power Take-Off System of an Oscillating Wave Surge Converter

“…While the PTO can mostly consist of commercial off-the-shelf components, maritime operating conditions need to be considered in reliability studies [10]. In addition to technical reliability studies, McAuliffe et al [19], Heikkilä et al [20] and Tiusanen et al [21] have published studies considering the linkage between economic profitability and the reliability of WEC technology. Reliability engineering should not be considered as a separate issue focusing on technical issues in systems engineering but rather as a process of interconnected efforts that complement each other and bring together technical, economic, operational and maintenance aspects [21].…”