Experimental study of geometrical and climate effects on the performance of a small solar chimney

Nowadays, referring to the increasing rate of environmental pollution and limitation on fossil fuel resources, the use of sustainable energies seems to be inevitable and an absolute necessity for the world. Renewable energies are known as the best alternative for solving the energy shortage and CO2 emission problems. Among the renewable sources, solar energy plays a significant role in aspects of accessibility of resource and diversity of energy conversion means. Solar chimney is a power plant that uses solar radiation to produce electricity by the created wind at the entrance of chimney. A solar chimney pilot power plant with 3 m collector diameter and 2 m chimney height was designed and constructed in University of Tehran, Iran. The temperature distributions and air velocity were measured and evaluated. The temperature difference between the chimney inlet and ambient reached to 26.3 °C. The output data for different collector inlet heights were obtained and the report shows that reducing the inlet size has a positive effect on the solar chimney power production performance. The air inversion at the latter of the chimney was not observed and it was found that this phenomenon directly associated with the geometry. The maximum air velocity of 1.3 m/s was recorded inside the chimney, while the collector entrance velocity was around zero.