Design and analysis of a hybrid solar power plant for co-production of electricity and water: a case study in Iran

The pace of implementing solar thermal power plants is increasing all around the world. In many cases, solar plants are installed in arid areas with severe demand for potable water despite the large availability of seawater. Thus, the solar thermal power plant is combined with a thermal desalination unit for the cogeneration of electricity and sweat water. Iran is a country with a very strong potential for solar projects, and of course, under an intense crisis of water. Shiraz plant is one of the solar thermal power plants in operation in Iran. The plant has recently gone under an expansion project to be combined with a gas-fired boiler, aiming to double its capacity yet smoothening its power output. This study investigates the feasibility of the co-production of electricity–water in this case study based on a number of innovative methods in conventional and modified configurations. All the proposed scenarios are designed, thermodynamically modeled, and analyzed. The different configurations are compared in terms of energy efficiency and production rate. The results indicate that the combined cycle with heat supply through the condenser of the power block, as well as the heat recovery unit allocated for the gas boiler, outperforms all the other possible configurations. In this case, the average efficiency is 10.76%, and a daily freshwater production as high as 852.32 Tonne per day is possible for a 500 kW power plant.