Though the Solar Chimney (SC) concept is one that has been around for nearly a century, this technology has regained momentum in recent decades. Several large-scale projects have been constructed, and others are in the process of being constructed. CFD and numerical analysis have allowed research to progress in characterizing the performance of SCs. Previous research has focused primarily on large-scale, high power production designs. The authors have validated these analyses empirically for small-scale, low power production SCs through the design and fabrication of a small-scale SC with adjustable geometries. The performance of the SC was characterized by the primary variable of chimney height. The effects of secondary variables were also measured and characterized: chimney diameter, collector height, and collector slope.
Results are presented showing that, though the numerical analysis and characteristic equations hold for large scale SCs, in small scale applications the reduction in size creates a greater dependence on the secondary variables in the overall performance of the SC. Optimization of both primary and secondary variables is discussed and demonstrated based on empirically gathered data. Though this study does not consider the turbine generator system, charge controller, or their efficiencies, power output as a function of collector geometry is discussed in detail.