Energy supply of a large size desalination plant using wave energy. Practical case: North of Gran Canaria

•Evaluation of the coupling of a large size desalination plant to a wave energy farm.•Most of the wave energy converters can meet the yearly energy demand.•A hybrid energy system is studied by combining solar photovoltaic and wave energy.•The hourly analysis is crucial to determine the matching between demand and supply.•Solar photovoltaics improves the matching in same cases but not in all. This research analyses the feasibility of supplying the energy demand of a grid-connected large size desalination plant by wave energy. One drawback of the wave technology is that it is not yet fully commercial and, therefore, many different technologies are available. Different arrays of wave energy converters have been selected for this study, comprising different type of technologies and technical characteristics. Two scenarios have been deployed, one based on wave energy and another one that combines wave energy and solar photovoltaic energy. The hourly analysis shows the matching between demand and supply. The aim is to establish if solar photovoltaic energy can improve the hourly matching between demand and production. The methodology proposed has been applied to a practical case which is a 15,000 m3/day reverse osmosis desalination plant located in the North of Gran Canaria, whose annual energy demand is 19 GWh per year. Results show that most of the wave devices selected are able to meet the yearly energy demand of the desalination plant although there are significant differences depending on the wave technology and in the hourly analysis. The combination of photovoltaic and wave energy improves the hourly matching in some cases but not in all. Thus, an hourly analysis of the specific technology is needed in each case.