Performance indicators for coupling desalination plants with wave energy

Abstract

This research work addresses the challenge of supplying desalination plants with electricity from waves. The vast majority of desalination plants are located in coastal areas, making wave energy a potential and viable cornerstone for the desalination sector. A series of performance indicators, such as freshwater production per sea covered area, are established and used in this study to evaluate different wave energy converters (WECs). Analyses of the performance of wave farms are undertaken. Some of the indicators are parameterized with the intention of extrapolating the results to other desalination plants, using the specific energy consumption of the desalination plant or the sea surface area covered by WECs. The study is developed for mid-range wave climates, comparing two zones with different sea conditions in order to establish correlations. The Canary Islands (Spain), where more than 600,000 m3 of desalinated water are produced each day, is the selected scenario. Results show that no correlation could be established between the wave resource and WEC output and confirm the need to simultaneously analyze the wave resource and the behavior of each technology in the selected marine area. It is also found that higher wave energy potential does not necessarily lead to higher energy production. Results also show that WECs can supply an important percentage of the desalination plant electricity demand and wave farm configurations have more similarities than single devices in terms of technologies.