The German R + D program "Solares Testzentrum Almeria" (SOTA) provided the scientific basis for the realization of advanced solar technologies including facility modifications, component tests and new lines of development. One of the working packages, WP 300, addressed the "Scientific Support" by the performance of preparatory studies, exploratory laboratory activities and qualified expertise. Universities, Research Institutes and Company R + D Entities in Germany were enabled to treat the following aspects: * Meteorological, system and cost investigations, * Development of important components as concentrator, receiver, storage, * Utilization of solar energy for process heat and chemical reactions. Besides the continued development of terminal concentrators, the studies concentrated in 1991 on the development of solar chemistry processes. The reports of the activities were finalized recently and collected in the present volume. The final reports were printed as received. The achieved results and the views expressed within the reports were under the responsibility of the authors. As organizers of these solar thermal activities and as editors of the corresponding final reports, we would like to thank BMFT and KFA-BEO for the farsighted funding (grant no. 0328823A) and the research groups for their engagement and consultations. We would also like to thank Ms S. Preusser and Ms U. Rachow, who among many others contributed to the realization of this volume.