In this study, we investigated the possible synergies between desalination technologies and solar energy in a remote energy system modelled as a small-size island with the goal to increase system sustainability. The solar systems implemented are photovoltaic panels (PV) and a Concentrating Solar Power system coupled with an Organic Rankine Cycle (CSP-ORC). For the desalination both Reverse Osmosis (RO) and Multi-Effect Distillation (MED) are considered. We found that the simple installation of PV is a valuable option to decrease electricity costs in remote context presently based on Diesel fuel generators but it struggles with achieving high penetration of Renewable Energy Sources (RES) ( >40%) due to the intermittent nature of solar energy and the consequent need for large batteries. The installation of a CSP-ORC allows further reducing the fossil fuel consumption thanks to the use of thermal energy storage and the effective integration with a MED facility. The results show that both solar energy technologies allow a considerable cost saving compared with the traditional solutions based on diesel generation. The most promising solution is a hybrid integration of all four above mentioned technologies, enabling RES penetration over 75% with > 10% of cost savings.