An automotive radiator is proposed for the heat rejection of the dense-array concentrator photovoltaic (CPV) system. Theoretical modeling on the integration of automotive radiator into the cooling system with a specially designed cooling block has been carried out in details. To verify the feasibility of new proposal, the automotive radiator cooling system has been constructed and tested to effectively lower down the temperature of CPV module in a non-imaging planar concentrator prototype with total reflective area of 4.16 m(2) at solar concentration ratio of 377 suns. During the on-site measurement, it has been observed that the conversion efficiency of CPV module has successfully improved from 22.39% to 26.85% when the CPV cell temperature is reduced from 59.4 degrees C to 37.1 degrees C. (C) 2012 Elsevier Ltd. All rights reserved.