Large-scale solar desalination by combination with CSP: Techno-economic analysis of different options for the Mediterranean Sea and the Arabian Gulf

• Combination of large-scale solar desalination with CSP in two representative areas
• Replacing the condenser by LT-MED is mostly competitive in the Arabian Gulf.
• CSP + LT-MED + TVC the recommended combination for CSP and desalination in Arabian Gulf
• CSP with RO performs better in the Mediterranean when evaporative cooling is used.
• CSP + LT-MED + TVC offers an opportunity in the Mediterranean when dry cooling is used.

The combination of desalination with concentrated solar power (CSP) plants (CSP + D) is considered as the most realistic opportunity for the development of large-scale desalination with solar energy. The availability of solar power and waste heat in CSP plants offers possibilities for both reverse osmosis (RO) and thermal desalination systems. In the case of RO the combination can be done directly by transporting the electricity. In the case of thermal desalination technologies there are different alternatives for coupling with CSP plants which can offer advantages with respect to the CSP + RO combination such as the reduction of the cooling needs of the power cycle. A techno-economic analysis of different schemes of multi-effect distillation (MED) systems coupled with CSP plants is presented here and compared to the CSP + RO option. The study is done using validated models of MED plants and considering the three conventional cooling methods available in CSP plants: dry cooling, once-through and wet cooling. The analysis is performed using operating conditions of real plants. The comparisons are done for the two main regions where the cogeneration of electricity and fresh water using CSP + D is proposed: the Mediterranean basin and the Arabian Gulf.