In this paper, we introduce a dynamic model of a thermal adsorber powered by solar energy. The system operates with silica gel (as an adsorbent) and water (as a refrigerant). The Finite Difference approximation was used; the obtained numerical model was then incorporated in a MATLAB code in order to solve the system of algebraic equations modeling heat and mass transfers. The real ambient temperature and solar radiation variations relative to a typical summer day in Fez (Morocco) are taken into account. The system is characterized by its simple design and can reach a SCOP (Solar Coefficient of Performance) of 0.15 under a condenser and evaporator temperatures of 27 degrees C and 5 degrees C respectively. Consequently, this installation can be an attractive solution to meet positive cooling needs (medicine and food storage) in off-grid electricity regions. It can be also proposed in humanitarian actions in Africa. (C) 2014 Elsevier Ltd. All rights reserved.