m respectively, the radius and angle of the solar collector are 607.2 m and 31o respectively, is designed to produce 5MW electric power on a monthly average all year. In the model building process, the author made some assumptions like ignoring the flow resistance losses and using boussinesq assumptions for air density. Fig.2 shows the solar chimney efficiency and system efficiency of the SSUPP during a year. It is obvious that the system efficiency and solar collector efficiency have similar curve tendencies through a year: efficiencies are both large in winter and spring days, whereas low in summer and autumn days, with the turning point in July. And, the two curves are approximately symmetrical to July. The author also gave detail expressions about the temperature increase, system pressure, airflow speed, system efficiency and solar collector efficiency.
Panse et al. [10] developed mathematical model considering the total energy balance. The factors influencing the flow of air inside the chimney (the sloped solar collector in SSUPP case) are: (i) heat losses to the surrounding, (ii) atmospheric lapse rate, (iii) frictional pressure drop and (iv) external wind near the outlet of the chimney. The complete energy balance per second of the SSUPP is given by: