Then the case of a solar tower power plant is considered. Operating without a storage system, this power plant generates a constant electrical power of 100 kWe, representing a heat energy absorbed by the receiver of 713.46 kW and corresponding to a steam mass flow of 0.3 kg/s. The goal is to provide a monitoring system, based on an energy analysis, to insure the adjustment of
the heliostat aperture area exposed to the sun depending on different parameters such as the direct normal irradiance. This study is carried out for case where the maximum aperture area is
4751 m2 corresponding to the DNI of 800 W/m2.