Performance analysis and optimization of an integrated azimuth tracking solar tower

Highlights: • A solar tower is installed on an azimuth tracking system. • The number of tracking devices is greatly reduced in Integrated Azimuth Tracking Solar Tower. • Numerical model is developed and validated for analysis and optimization of performance. • High optical efficiency solar tower system is designed. A new design named as integrated azimuth tracking solar tower is presented in which all of the heliostats and receiver are installed on an azimuth tracking device, multi heliostats are fixed to one horizontal shaft which rotate to track the solar elevation variance to reduce the number of tracking device. An optical and thermal performance model is developed and validated for it. Its annual performance is studied and the design is optimized with the model. The results show that the annual averaged optical efficiency of optimized design is about 77%, and net solar heat efficiency is about 70% with a geometrical concentration ratio of 300. Its efficiency is rather near to the solar dish, and about 20% higher than that of the conventional solar tower system. The increased efficiency comes mainly from the improvements of cosine factor as it always works with azimuth = 0. Only 88 tracking devices are needed for two direction tracking of 1200 heliostats. The number of tracking devices is greatly reduced to decrease the cost and system complexity, increase the availability of the system. So the integrated azimuth tracking solar tower may be a potential solar energy technology.