An analytical model and a thermodynamics study of the steady airflow inside a solar chimney are performed in this paper. A simplified Bernoulli equation combined with fluid dynamics and ideal gas equation are modeled and solved using EES solver to predict the performance of a solar chimney power plant. The analytical model is validated against an experimental and numerical data available in the literature. The developed analytical model is used to evaluate the effect of geometric parameters on the solar plant power generation. The analysis is showing that the height and diameter of the tower are the most important physical variables for the solar chimney design. The collector area has minimal effect on second-law efficiency but strong effect on harvested energy. The second law efficiency has non-monotonic relation with the turbine head.