Evaluation of effect of diurnal ambient temperature range on solar chimney power plant performance

Abstract

This paper conducts numerical simulations of a large scale solar chimney power plant (SCPP, also called solar updraft power plant) based on an assumed expression of daily ambient temperature profile with a constant peak. It then evaluates the influence of the diurnal ambient temperature range (DATR) on the performance of the large scale SCPP. Results indicate that larger DATR accompanied by a bigger drop in ambient temperature at night increases the plant power output considerably during nighttime but decreases the power output during daytime noticeably. This is because larger DATR leads to more heat released from the thermal storage layer to produce more power during nighttime, and less heat for less power during daytime at a given solar radiation input. In this case, only a little increase in daily total power output but a significant drop in the daily power peak-to-valley ratio (PVR) are reasonable. It is also found that DATR acting as a meteorological resource for SCPPs is not as important as solar radiation, but as high humidity, in terms of enhancing the power potential of the plants. Compared to the humidity and solar radiation intensity, DATR is a good factor in smoothing daily profile of the plant power output.