Costs investigation of coupling an RO desalination system with a combined cycle power plant, using DEEP code

The decision to use a desalination system as well as the selection of the most appropriate combined energy source depends on several parameters. The main are the low investment, the low maintenance requirements, a simple operation and a high reliability. This paper discusses the costs dependence from such parameters in the case of an RO desalination system coupled to a combined cycle power plant supplying both electricity and heat. An economic analysis is made for specific site data using DEEP code and the technical designs available in the program. The sensitivity of the levelized water cost from construction water plant cost, discount rate and operation and maintenance costs is established, taking into consideration that these parameters constitute the major constraint to the development of desalination water plants; water costs are determined for adequate economic hypothesis used in Morocco or recommended by international organizations such as IAEA and OECD.

Fig. 3. Effect of the variation of the discount rate SCC: specific construction cost. The DEEP model for cogeneration and desalination economic evaluation has been used in this study for an economic analysis of an RO desalination system associated to an independent combined cycle power plant. The water plant capacity has been fixed to 36,000 m3/d, which is an average size of future desalination systems expected to be installed over the medium term in the south of Morocco.