Several cost models for large-scale solar chimney power plants are available in the literature. However, the results presented vary significantly, even in cases where the input parameters and the used models are supposedly very similar. The main objective of this paper is to clarify this matter by comparing previous cost models to a newly developed alternative model. Further, the impact of carbon credits on the levelised electricity cost is also investigated. A reference plant is introduced, with dimensions and financial parameters chosen specifically for the purpose of making the results Of this analysis comparable to those of previous publications. Cost models are presented for the main components of a solar chimney power plant, i.e. the collector, the chimney and the power conversion unit. Results show that previous models may have underestimated the initial cost and levelised electricity cost of a large-scale solar chimney power plant. It is also shown that carbon credits significantly reduce the levelised electricity cost for such a plant. (C) 2008 Elsevier Ltd. All rights reserved.