Desalinators are traditionally driven by fossil-fuels but in order to avoid greenhouse emissions, renewable energy must be used. In this paper, a coupling between multi-stage flash distillation apparatus and a parabolic trough solar collector is analyzed. The purpose of this study is to determine the economic feasibility of the system, considering four cities of Saudi Arabia and three different potable water productions. To avoid solar energy intermittency and unavailability at night, thermal storage is implemented. Whereas other researchers made parametric analyses, in this paper, the authors developed a mathematical program which was optimized with the help of GAMS software, where the capital cost of the plant was the objective function. After that, a life cycle cost analysis was carried out for each scenario. Depending on the region and water production, the costs of drinking water vary from 2.26 to 3.93 US$/m³, and from 7440 to 23825 tons of carbon dioxide emissions are avoided. As a consequence of the approach used, low costs are obtained; even though no auxiliary heater is implemented and the lowest irradiance conditions are considered. The results of this study reflect that the proposed process is competitive with respect to the traditional one.

This work presents an innovative tri-generation system for the simultaneous production of desalinated water, electrical energy, and cooling, aimed at addressing the growing challenges of water scarcity and climate change. The system integrates an 8-stage MSF process and a 6-effect MED process, along with an expander-generator that improves cycle efficiency by utilizing and reintroducing steam within the desalination stages. A parametric study was conducted using ASPEN PLUS to evaluate the system’s performance. The analysis showed that the system operates over a broader pressure and temperature range than conventional MED systems, from 28.3 to 0.8 kPa and from 68 to 4°C, thanks to a dual ejector-condensation process. In cogeneration mode, the system achieves a PR of 12.06 and an RR of 54%0.54, producing 67,219.2 L/day of desalinated water and reducing electrical consumption by 12.03%. In tri-generation mode, it achieves a PR of 17.81 and an RR of 0.80%, with a cooling capacity of 1225 kW (COP of 3.278), producing 99,273.6 L/day of desalinated water while reducing electrical consumption by 3.69%. This system offers an efficient solution to meet the growing water and energy needs of coastal communities, combining water desalination, energy production, and cooling in a single integrated process.