Hybrid desalting systems for avoiding water shortage in Spain

This paper presents the economic analysis of the Ebro River transfer (a tot al amount of 1.050 hm(3)/y) presented for the Spanish Government in his pro ject for the National Hydrologic Plan and its alternative: drinking water o btained from desalination plants. In this paper is proved that the cost of the desalted water is similar to the transferred one, by using conventional reverse osmosis (RO) methods or hybrid methods combining thermal and membr ane desalination processes. The sensitivity analysis of the desalting alter native is mainly restricted to the plant size and the energy prices (natura l gas or electricity). The new concepts of the global cycle of non-conventi onal water resources (desalt, use and recycle) is also introduced in order to decrease the water cost for urban supply.