The Solar Tower Power Plant SSPS was developed in 1980 in the Plataforma Solar de Almeria (PSA) on the edge of the Tabernas Desert in Spain (Fig. 5). The plant had 92 heliostats (40 m²) producing 2.7 MWth at the focal point of the 43-m-high tower where the heat was collected by liquid sodium. The PSA has a number of experimental plants such as the CESA-1 7-MWth central receiver system and the SSPS-OCS 1.2-MWth parabolic-trough collector system with associated thermal storage.