Performance investigation of a solar updraft tower concept with downdraft windcatcher

•A novel solar updraft tower with windcatcher has been studied.•Transpired solar collectors are used in the concept.•Two counter-rotating vertical axis turbines are used in the concept.•Diffuser-shaped downdraft tower acclerated incoming wind up to 2.5 times.•Power generation increased 8 times compared to traditional updraft solar tower. In this study, a novel solar updraft tower system that combines updraft and downdraft is examined, its functional principle is explained and its performance is presented. A prototype was built at Faculty of Engineering of Trakya University in Edirne Türkiye in 2017. The concept includes counter-rotating dual drag type vertical axis turbines, wind catchers, three prismatic diffuser towers and sloped transpired solar collector. The results showed that the downdraft wind catcher integration increased annual energy production by 8 times compared to a conventional solar updraft tower. In the diffuser-shaped downdraft tower, the incoming wind accelerated up to 2.5 times. The power potential, which is 160 W for the conventional system, becomes 83 kW at a wind speed of 10 m/s and a downdraft pressure coefficient of 1.0.