A numerical investigation of the performance of a multi paned smart window integrated with water-cooled high efficiency third generation GaAsP/InGaAs QWSC (similar to 32% efficiency) solar cells illuminated by two-axis tracking solar concentrators at 500x in the inter pane space is presented. Optimising system parameters such as optical concentration ratio and coolant (water) flow rate is essential in order to avoid degradation in system performance due to high cell temperatures and thermal stresses. Detailed modelling of the thermofluid characteristics of the smart windows system was undertaken using a finite volume CFD package. Results of this analysis which considered the conductive, convective and radiative heat exchange processes taking place in the interior of the smart window system as well as the heat exchange to the internal and external ambient environment are presented. (C) 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/).