Wave Energy Converter Annual Energy Production Uncertainty Using Simulations

Abstract

Critical to evaluating the economic viability of a wave energy project is: (1) a robust estimate of the electricity production throughout the project lifetime and (2) an understanding of the uncertainty associated with said estimate. Standardization efforts have established mean annual energy production (MAEP) as the metric for quantification of wave energy converter (WEC) electricity production and the performance matrix approach as the appropriate method for calculation. General acceptance of a method for calculating the MAEP uncertainty has not yet been achieved. Several authors have proposed methods based on the standard engineering approach to error propagation, however, a lack of available WEC deployment data has restricted testing of these methods. In this work the magnitude and sensitivity of MAEP uncertainty is investigated. The analysis is driven by data from simulated deployments of 2 WECs of different operating principle at 4 different locations. A Monte Carlo simulation approach is proposed for calculating the variability of MAEP estimates and is used to explore the sensitivity of the calculation. The uncertainty of MAEP ranged from 2%-20% of the mean value. Of the contributing uncertainties studied, the variability in the wave climate was found responsible for most of the uncertainty in MAEP. Uncertainty in MAEP differs considerably between WEC types and between deployment locations and is sensitive to the length of the input data-sets. This implies that if a certain maximum level of uncertainty in MAEP is targeted, the minimum required lengths of the input data-sets will be different for every WEC-location combination.

WEC Design Based on Refined Mean Annual Energy Production for the Israeli Mediterranean Coast

“…In addition, WEC survival will need to be considered in light of extreme loads due to very steep waves (see Boccotti (2014)). Employing time-domain models Hiles et al (2016), and taking into account the statistics of high waves and the forces associated with their impacts on marine structures Fedele and Arena (2005); Arena (2005); Romolo and Arena (2008); Boccotti et al (2012) will allow for a more holistic, albeit computationally demanding, perspective on WEC survival than considered here.…”

“…While it has been possible to base the foregoing analysis on purely hydrodynamic considerations, there is at present no widely accepted nor implemented survival mode to protect floating-body WECs when normal operating conditions are exceeded Coe and Neary (2014); Peckolt et al (2015). The existing literature largely suggests strict cut-offs based only on H s , rather than device response Maisondieu (2015); Hiles et al (2016). Consequently, the choice of a cut-off is necessarily somewhat arbitrary, and should be understood as an illustrative refinement of the MAEP rather than a strict limit.…”

Breaking-Down and Parameterising Wave Energy Converter Costs Using the CapEx and Similitude Methods

“…A large part of the research in wave renewables is dedicated to AEP [28,31,32] and its calculation [25]. Therefore, AEP is probably the most reliable metric of LCoE [33,34] to date, whereas the cost remains a source of uncertainty. The cost is composed of the operation and maintenance costs (or operational expenditure, OpEx) and the capital expenditure (CapEx) that gathers all the other costs of LCoE [35].…”

Joint Modelling of Wave Energy Flux and Wave Direction

“…In order to make wave energy production feasible and economically viable, it is necessary, among others, to deploy wave energy converters (WECs) based on the accurate knowledge of the wave climate and its temporal variability in the area of interest [6]. The wave climate variability is also responsible to a great extent for the uncertainty in electricity production of a wave energy project, an aspect that has been studied by [7,8].…”