A novel model of the solar-driven thermodynamic cycle system which consists of a solar collector and a Braysson heat engine is established. The performance characteristics of the system are optimized on the basis of the linear heat-loss model of a solar collector and the irreversible cycle model of a Braysson heat engine. The maximum efficiency of the system and the optimally operating temperature of the solar collector are determined and other relevant performance characteristics of the system are discussed. The results obtained here may provide some theoretical guidance for the optimal design and operation of solar-driven Braysson and Carnot heat engines. (C) 2004 Elsevier Ltd. All rights reserved.