The Central Receiver System

As may be seen from the schematic in Fig. 8, the CRS plant consists of a field of 93 heliostats which reflect the sun onto a heat capturing device called a “receiver”. The heliostats track the sun during the day keeping its image reflected onto the receiver aperture. Each heliostat consists of a number of mirrors which are adjusted individually in angle and curvature so as to obtain as small an image of the sun as economically practical. The receiver is mounted on top of a tower in order to make it possible for each heliostat to “see” the receiver at all times. The receiver absorbs the solar radiation and transmits the heat to a suitable working fluid, in this particular case, liquid sodium. The heated sodium is first pumped through a hot storage tank which provides a reserve of thermal energy for limited amount of time and also passes through a heat exchanger which is called the “steam generator”; it produces the steam required to run the power conversion system [I,2.].