Solar updraft power plants (SUPPs) form a very modern and rather efficient solar power technology. SUPPs consist of the glass-covered collector area (CA), in its centre the solar chimney (SC), and around the SC's perimeter the power conversion unit (PCU). To evaluate the power/energy harvest of such plants, computer simulations comprise all physical processes in the mentioned plant components. For this purpose the thermo-fluiddynamics is described and formulated. An important aspect is the modeling of the transformation of the solar irradiation into heat-flux of the collector airflow, requiring the combination of different physical fields, such as thermodynamics, fluidmechanics and radiation-physics. All this leads to a highly nonlinear process description for the SUPPs' power harvests, for which solution fast computer algorithms are developed. In the course of the treatment, typical process variables of SUPPs are explained, and computed results for investigated plants demonstrate the capability of the derived software and the efficiency of SUPPs. The suitability of solar updraft power technology for arid zones in the world is finally detailed by example of two especially optimized SUPP-families. (C) 2013 Published by Elsevier Ltd.