Venezuela is a country with a great deal of water resources. In spite of this, about 1.6 million inhabitants are dispersed in remote regions where water distribution is problematic due to the lack of this resource. A flat plate solar collector was built as a component of a single-stage Multi-Effect Humidification (MEH) desalination plant prototype, and its characterization was done on a testing rig designed and constructed according to the ANSI/ASHRAE 93-2003 standards. In order to optimize the operation of this equipment, the exergetic change of the working fluid across the solar collector was maximized. This objective was accomplished through a numerical simulation of the solar collector performance using a predictive algorithm and available yearlong meteorological data. It was found that a mass flow rate equal to 0.006 kg/s (0.36 LPM) should be maintain to ensure the maximum exergetic gain of the working fluid for an inlet temperature of 54°C.