On the Optimum Sizing of a Real WEC From a Techno-Economic Perspective

Abstract

When designing “multi-MW arrays” of Wave Energy Converters (WECs), having a low number of converters with high individual power ratings can be beneficial as the Operation and Maintenance (O&M) costs may be reduced. However, having converters of small dimensions or small power ratings could also be beneficial as suggested by previous works due to a reduction in material costs as compared to power production, the use of small, inexpensive vessels. In this work, a case study investigating the optimum size of WEC for a 20MW array is performed. Analysis is carried out based on the CorPower Ocean technology. In this case study, firstly a Levelized Cost of Energy (LCOE) model is created. This model incorporates the latest Capital Expenditure (CAPEX) estimates for CorPower Ocean’s 250 kW prototype. Using this techno-economic model, several sizes/ratings of WEC are tested for use in a 20 MW array. Operational Expenditure (OPEX) is calculated using two different calculation approaches in order to check its influence on final indicators. OPEX is firstly calculated as a percentage of CAPEX, previous works, and secondly using a failure-repair model, taking into account individual failures of WECs in the array. Size/rating analysis is carried out for several European locations in order to establish any dependence between site location and optimal WEC size/rating.

Strategically estimated CapEx: wave energy converter costs breakdown and parameterisation

“…Two parameters were selected to be the "Scale" from Equation (4), to apply the Similitude method from de Andres et al [35] to Wavepiston, following Froude law similitude representative dimension: Wavepiston plate width and total length. parameter.…”

“…To sum up, this method can only be applied to a couple of elements from the WEF enabling only a partial flexibility of the CapEx calculations. g. For a given WEC, de Andres et al [35] provided a method (also applied by Pascal et al [15]) scaling the CapEx with references to the Froude law similitude [50] used initially to scale marine structures in different sizes. In their study, de Andres et al [35] adapted the Froude law for its application to CapEx.…”

“…g. For a given WEC, de Andres et al [35] provided a method (also applied by Pascal et al [15]) scaling the CapEx with references to the Froude law similitude [50] used initially to scale marine structures in different sizes. In their study, de Andres et al [35] adapted the Froude law for its application to CapEx. Yet, this approach remains global and lacks specific control in the calculation of the cost composing CapEx.…”

“…Chang et al [8] amongst others [20,32,33], have estimated the cost for most of the devices investigated by Barbarit et al [34]. Furthermore, specific costs have also been provided for CorPower Ocean [35,36], Pelamis and Wavestar [37], Wavedragon [38], Floating Power Plant A/S [39], M4 [40], and Seabased Industry AB [41], to name a few. These studies mainly used selected economic indicator-based equations such as the LCoE.…”

“…Functionality-related dimension of Wavepiston WEC elements and sub-elements following de Andres et al[35] …”