The valorization of the hydroxide sludge, from drinking water treatment plants and solar energy in Morocco, is the main aim of this contribution. In fact, the performance of open and closed solar greenhouse systems were analyzed by comparing with the external and internal meteorological conditions of this greenhouse. The hydroxide sludge from three different sites in the “Marrakech-Safi” region of Morocco was simultaneously dried inside the considered greenhouse. Moreover, the drying kinetic of the samples, during the drying process, was carried out. Based on the drying curves, it was found that the drying time depends on the temperature, higher temperature means shorter time and faster drying speed. In addition, it was revealed that the closed dryer, in the summer season, raises high temperatures and efficiency, and the drying time was reduced compared to the winter season. the moisture content at the end of the process was 71%, the dryness of the sludge was increased from 14.7 to 80%, the characteristic drying curves of the summer and winter periods were made. The cylindrical shape of the samples was constantly measured to follow the shrinkage as well as the geometric reduction of the product.