Solar chimney power plant (SCPP) is an alternative technology for electricity generation from solar energy. The aim of this study is to investigate the performances of solar chimney. A small-scale prototype of solar chimney power plant was built in Ouargla University, Algeria. A theoretical model is developed in this study to evaluate the performances of a solar chimney and the effects of the chimney height on the chimney efficiency and the power output. The standard turbulence numerical model of CFD is adopted to simulate air flow in the solar chimney prototype. The study found that the air velocities measured at the chimney inlet are in a good agreement with the predicted ones by the use of CFD model. The simulation results show a recirculation zone at the inlet of the collector with negative velocities which cause a reduction of the solar chimney performances. Furthermore, a maximum air velocity of 1.6 m/s in the entry of the chimney was observed. In addition, a disturbance zone is observed at the inlet of the chimney and the air particles are randomly oriented. This disorganization of the velocity field causes a loss of kinetic energy by a pressure drop. The variation trend of theoretical generated power output in the SCPP prototype follows the same trend of the solar irradiance and reached around 1.10 W between 10:00 to 17:00. Using the Manzanares SCPP prototype dimensions and the meteorological parameters conditions of Ouargla, we found that the predicted power output produced reached 104 kW which is greater than the power produced in Manzanares City (75 kW). These results show that solar chimney technology is very suitable for the hot and arid zones like the southeast of Algeria.