The solar chimney power plant is a solar power plant for electricity generation by means of air flow induced through a tall chimney. Guided by a theoretical model, this paper uses CFD technology to investigate the changes in flow properties caused by the variations of flow area. It is found that the sloping collector roof affects the plant performance. The divergent-top chimney leads to augmentations in kinetic energy at the chimney base significantly. The proper combination between the sloping collector roof and the divergent-top chimney can produce the power as much as hundreds times that of the conventional solar chimney power plant. (C) 2013 Elsevier Ltd. All rights reserved.