Combined concentrated solar power plant with low-temperature multi-effect distillation

Abstract

This study analyzes a technological concept for simultaneously generating power and desalinating water in a Middle East and North Africa country. An innovative, low-temperature, multi-effect desalination (LT-MED) process integrated with a concentrating solar power (CSP) plant was assessed and analyzed. A combined power and seawater desalination plant was modeled for the city of Aqaba by the Red Sea in Jordan. Parabolic-trough collectors using indirect steam generation with thermal energy storage connected with power and desalination blocks were designed. The designed plant was modeled and simulated using EBSILON Professional, a discrete energy balance simulation software, under several operating conditions, to analyze the results. An economic feasibility analysis of the combined CSP+LT-MED plant was also conducted. The simulation results showed the broad variability of the cogeneration system in terms of electricity generation and water production. The output power of the CSP plant without water production reached 58.7 MWel in June. The output power accompanied with distilled-water production with a mass flow rate of 170 m3/h was approximately 49.5 MWel. Furthermore, the number of desalination stages had the strongest influence on distillate production but limited the operational flexibility of the power plant due to the temperature gradients within the desalination stages. The distilled-water mass flow reached 498 m3/h for 10 stages. The research showed that the design successfully worked with up to €78.84 million, earned from selling the produced electricity. However, owing to highly subsidized water tariffs in Jordan (80% less than the actual cost), the integration of water desalination into the CSP plant was not economically feasible.