In the last few decades, the energy demand is increasing globally which, given the present dependency of the energy generation on fossil fuels, results in a continuous increase in CO2 emissions. In an isolated electric grid system like in the SIDS, the majority of the electricity is produced by fossil fuels, therefore most of the SIDS nations are now focusing on Variable Renewable Energy sources (VREs). VREs such as wind and solar are hardly predictable and bring instabilities in the electric power system if not buffered by a storage system. Here we investigate the possibility of using Seawater Pump Storage Hydropower Systems (S-PSHS) as a renewable energy storage solution in an isolated electric grid. For this, the island of Curaçao (one of the SIDS nations) is used as proof of the concept. For detecting potential locations for the S-PSHS sites on the island, GIS application was developed. The application of this conceptual proposed solution in similar systems is straightforward and it can be easily upscaled in other geographies. The concept of using seawater for the pumped hydro project is not common in practice and it is anticipated to have technical, environmental and financial challenges which are discussed in this paper.

Based on the non-linear finite element analysis, the maximum bearing capacity of a plain circular concrete lining subjected to external and internal pressure is investigated. Numerical results regarding elastic stresses and deformations are compared with those calculated using the classical thick-walled cylinder theory. Referring to the discrete cracking concept and assuming that the concrete behaves as a brittle material, the redistribution of stresses after cracks have occurred is further investigated. The normal tensile strength in the lining will reduce to zero as soon as the joint element is cracked. These analyses confirm that the proposed modelling method may be used satisfactorily, to model the cracking process of passive pre-stressed circular concrete linings.