The development of a simple dynamic computer model allows the performance and operational behavior investigation of a large solar seawater desalination system based on a multi-effect distillation plant and a solar pond, which is believed to be the most promising large-scale solar desalination technology known today. The whole system of dynamic behavior of the whole system is investigated, and annual water yield predictions are made during the thermal transient build-up and quasi-steady-state system operation. The effect of various design and operational parameters on system behavior are investigated. Results are offered for system sizing, design and water yield predictions, as well as system economic evaluation. Based on up-to-date construction experience, rates and market costs of components and labor, as well as updated costs of commercially available desalination plants, predictions of the unit water cost are made according to which appears to be most competitive with water cost from conventional resources in several arid and semi-arid geographical locations.