Impacts on the Electrical System Economics from Critical Design Factors of Wave Energy Converters and Arrays

Abstract

It is expected that ultimately, like offshore wind farms, electrical systems will make up to a quarter of the overall Capex of wave farms. This is a significant element of cost and consideration must be taken in the design of both individual wave energy converters (WECs) and arrays of WECs to ensure that these costs can be minimised. In a worst case scenario design decisions could increase the cost of the electrical system by several orders and ultimately make the technology uncompetitive. This paper outlines the impacts on the cost of the electrical system arising from design factors of WECs and WEC arrays or wave farms. The paper uses a cost model to examine the impact to the cost of WEC array electrical systems caused by changing of key design factors. The design factors examined include WEC unit rating, capacity factor, interface to the electrical network, array spacing, export voltage, array design, site selection, export distance, and WEC dynamic response. All of these design factors have an impact on the economics of the electrical system and hence the economics of the wave farm as a whole. The paper concludes that there are some critical design choices which should be avoided if a cost-effective wave farm is to be established. It is also concluded that some design choices could ultimately reduce the overall Capex of WEC arrays enhancing their competiveness. Keywords— Wave Energy, Electrical Networks, Capacity Factor, Submarine Cables, Economics