The need to minimize energy reliance and its repercussions and accretivewater scarcity necessitates research into renewable energy resources. Hybrid renewable energy systems are an apparent solution for areas and countries like Greece, especially when combined with seawater-pumped storage hydropower systems, where wind potential and topography foster such approaches. Moreover, it is essential to understand the uncertainty of the involved natural processes and incorporate their stochasticity in these hybrid systems, moving towards a more realistic approach. This system is simulated under uncertainty and has a total capacity of 31.5 MW and aims to cover the water and energy needs of Karystos, combining 9 wind turbines of 3.5 MW each, a desalination plant of 9,600 m3/day, a desalinated water tank with a capacity of 100,000 m3, a 9 MW pumping station, and a seawater pumped storage hydropower system with a 1.7 hm3 storage tank. Some promising results of this system under study are 99 % reliability for drinking water needs and 63 % and 85 % for irrigation and energy needs respectively, with the wind park contributing 54.4 % and the hydropower system 31.3 %.