Towards 100% renewable energy islands: The role of the water cycle

Abstract

El Hierro Island (Canary Islands, Spain) has become a referent of 100% renewable energy island. Gorona del Viento Wind-Hydro Power Plant already covers around 60% of its annual electricity demand (2018), often hitting peaks of 100%. In this context, the energy-water nexus is one pillar to become a 100% renewable energy island. Water resources management, which includes groundwater extraction, seawater desalination, water pumping and distribution, represents around 35% of the annual electricity demand of the island, a clear sign of the interdependency between energy and water. In this context, the aim of this study is to propose a strategy to increase the share of renewable energies by supplying the water cycle load only with wind energy. The potential surplus of wind energy has been estimated, concluding that the wind production could theoretically be increased by 28% (wind energy that is currently not being produced). Therefore, the scenario proposed is to supply the whole water cycle (groundwater extraction, seawater desalination, pumping and distribution) only with wind energy and propose the strategies needed to guarantee the water supply during the whole year. According to our results, the coupling between wind energy and the water cycle does not only contribute to better integrate intermittent renewable energy generation but also to the decarbonization of the desalination sector.