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Due to increasing energy prices and the anticipated increase of freshwater demand in the Middle East and North Africa (MENA) region, it is essential that water is desalinated at a low cost. The estimation of the product costs of a co-generating system (electricity and water) can be calculated using a methodology of exergoeconomics. A co-generation concentrating solar power tower with an integrated low temperature desalination model plant is analyzed using methods of exergy and exergoeconomics. The plant is located on the Red Sea coast in Egypt and has been simulated using meteorological data measured by a local weather station. The economic and exergy analysis gives the input for the exergoeconomic evaluation. There are two operational cases examined: In Case 1, the water output and in Case 2, the electricity output is maximized, respectively. The electricity generation costs are calculated to 0.2051 USD / kWh and 0.2079 USD / kWh . The water generation costs are calculated from 0.8464 USD / m 3 to 0.3991 USD / m 3 for the two cases. The interpretation of the results are performed using the sensitivity analysis which shows that the number of full load hours during the year have the biggest influence on product costs. The comparison of the calculated results with a lost-kilowatts cost accounting method shows the shortcomings of the exergetic analysis considering the economic value of fresh water. From the exergoeconomic analysis can be concluded that the use of condensation heat has a positive effect on the overall plant balance. Considering the economic viability, is essential to reduce the investment costs for solar energy related components. [ABSTRACT FROM AUTHOR]

The thermal desalination systems like multi-effect distillation and multi-stage flush have gone through a strong development process to increase energy efficiency and to improve energy recovery. While these improvements have led to lowered energy consumption, different concepts could be necessary to adapt the thermal desalination systems to renewable energy sources. A specially designed low-temperature desalination driven by low-grade waste heat can be used to desalinate seawater and to clean polluted water with a higher conversion ratio than existing systems. The reason for this improvement is a drastically improved heat transfer of this system, using spray systems for evaporation, and condensation. It was tested in a demonstration plant in El Gouna, Egypt, in cogeneration with diesel generators which used 7 MWthto desalinate 500 m³/d. This paper introduces a model of the low-temperature desalination process, which is derived from experimental data and technical specifications. It required the development of energy, mass, and material balances of the media streams with respect to the measured data from the demonstration plant. The model is implemented using the energy process simulation software “Ebsilon Professional” and combined with a 10-MWthconcentrating solar power (CSP) plant. The results show the cogeneration of 2.2 MWelpower in the CSP plant and 520 m³/d fresh water in the desalination. Furthermore, the output depends on various process parameters like cogeneration fraction, temperature levels, and input salinity, which are analyzed and discussed. [ABSTRACT FROM PUBLISHER]