Concentrating solar power and desalination plants

Abstract

Many developing countries face serious water and electricity shortage, which make water and energy supply a matter of national security that requires cost-effective and reliable processes. Thermal desalination processes have been an answer for the shortage of drinkable water especially in the Middle East and North Africa. The problem is that these processes are intensive energy consumers, so if fossil fuels are used as a primary energy source, it will lead to a negative impact on the environment due to the CO2 emissions. Improving the efficiency of this technology will be a good solution for the growth of these countries, which, in turn, have high insolation levels. In this scenario, freshwater and electricity cogeneration by integrating desalination plants into concentrating solar power plants (CSP+D) is proposed as one of the most sustainable options to solve water and energy. It seems clear that the best integration concepts should be chosen in order to maximize the freshwater and power production. This chapter shows a state of the art of desalination processes powered by concentrating solar technologies, considering the most promising desalination technologies: multi-effect distillation and reverse osmosis. The impacts of the location site and the choice of the cooling system on the overall efficiency of the CSP+D plant and their electricity and water costs are discussed and compared between each other. Though no CSP+D plant has been built yet, the current ongoing research can help to decide which desalination process is more suitable to be coupled to a CSP plant, depending on the location in which the project will be implemented.