This paper introduces a mixed integer non-linear mathematical model for a simulation of a hybrid energy source consisting of photovoltaics (PV), wind turbines (WT) and pumped storage hydroelectricity (PSH). The concept of PV–WT–PSH has been well described and evaluated for sparsely populated or remote areas such as islands. Here, due to the rapid development of renewable energy sources and most importantly the variable (non-dispatchable) energy sources such as wind and solar, the idea of wind and solar powered PSHs has been investigated in the context of the national energy system. The economic and environmental impact of the proposed hybrid has been assessed. The results reveal that to cover almost 40% of the energy demand one should expect the energy cost to increase by 25%.