Unlike conventional solar stills, the present system utilizes the latent heat of condensation and the sensible heat of the discarded seawater. The performance was optimized analytically and the system is presently under construction in Egypt. The system consists of a humidifier, a solar still or channel, a condenser, and a pond. In the humidifier, ambient air is humidified and heated by a warm brine from the pond. If the brine outlet temperature is higher than the ambient temperature, it goes back to the pond, if not, it is discarded. The solar still is a long glass-covered channel, about 200 meters long.