Energy Utilization Factor of Solar Tower Systems

The solar tower system is one of the most promising concentrated solar power technologies that can address climate change issues by meeting energy demand sustainably while mitigating carbon emissions. The mirrors of the solar tower require a large share of the investment cost and occupy 4-8 times the ground compared to the mirror surface area. The share of the plant area cost may become significantly high for regions where the land is not cheap, especially in developing countries. In this study, a parameter named Energy Utilization Factor is introduced to quantify the utilization of the ground area in terms of available solar radiation energy. The variation of the Energy Utilization Factor is studied for a range of design variables without considering any specific dimensions for the heliostat and the receiver. The annual Energy Utilization Factor is seen to have a maximum value within 15 %, indicating the solar tower system is only capable of using one-seventh of the available solar resource on the ground. The maximum achievable Energy Utilization Factor is seen to increase with the tower height, but reduces with latitude. For a given heliostat field, the Energy Utilization Factor is seen to have a direct relationship with the amount of mirror area employed per unit ground area.