This paper presents a modeling and optimization investigation of a solar driven adsorption cooling system working with activated carbon methanol pair. It deals with the effect of internal fins on the thermal behavior of the adsorber and on the system performance. A two-dimensional model describing the coupled heat and mass transfer in the adsorbent bed and energy balance in the main components of the solar collector is presented. Furthermore, a simulation code based on alternating direction implicit method is developed. This model has been validated by experimentation data. The analysis of the thermal behavior of adsorbent indicates that heat and mass transfer within the adsorbent is enhanced by increasing the number of fins. The simulation results show that, under the climatic, operating and design conditions of the system, the solar coefficient of performance is roughly invariant with changes in number of fins. The results indicate also that the thermal coefficient of performance is improved by increasing the number of fins. However, it is found that there is an optimal range of number of fins varying from 15 to 20 that allows obtaining an optimal performance; the corresponding range of fin spacing is found to be between 4 and 5.2 cm. (C) 2015 Elsevier Ltd. All rights reserved.