In this study, photovoltaic/thermal (PVT) panels are employed as a roof of the solar chimney power plants (SCPP), to enhance the power generation and exergy efficiency. A parametric study is conducted to scrutinize the influence of the effective parameters on the performance and energy/exergy/exergoeconomic (3E) indicators of the SCPP, PVT and SCPP/PVT system using EES software. Eventually, the proposed system is optimized by multi-objective optimization (MOO) based on a genetic algorithm to determine the optimum solution points from 3E standpoints and also the well-balanced solution point. Results of the parametric study reveal that the SCPP/PVT system operates more efficiently at lower PVT cell temperature. Results of the MOO demonstrate that at the well-balanced operating point, total exergy efficiency and cost rate of the SCPP/PVT were obtained as 3.304% and 241.6 $/h, respectively. Eventually, scatter distribution of the effective parameters indicates that the height of the tower should be around 300 m. The proposed renewable-based energy system is a promising and applicable method to considerably enhance the power production and exergy efficiency of the SCPPs. (C) 2018 Elsevier Ltd. All rights reserved.