Abstract :
In solar power tower plant, the amount of energy exploited of direct solar radiation depends to the angle between the solar rays and the heliostat position in the solar field. The maximum incident solar radiation on the heliostat be when the sunrays are perpendicular to the heliostat reflection area. That cannot exist in full sunny day for reason of cosine loss effect due by the variation of the sun position, which affected the efficiency of a heliostat. This paper shows new approach of installing the mobile target of sunrays receiver to minimize the cosine losses of the heliostat field in the solar power tower plant for increasing his efficiency. The simulation results validated the advantage of uses the mobile target in the central solar tower. In addition, it illustrates the possibility of eliminating the cosine losses based on changing the target position.