The greenhouse solar system is a large multipurpose solar air collector in which a drying process or a plant production process takes place for effective year-round solar energy utilization. The basic facilities of the system can be used for both processes at an initial cost of the solar unit not exceeding that of a conventional tobacco bulk-curing unit. The tobacco-curing process is a complicated drying process, which requires the highest energy consumption per unit of dried weight among all crops. Solar energy is ideally suited for tobacco curing, since the curing is done during the months of July and August when solar energy is at its peak. The !structure and facilities are used to produce greenhouse crops and tobacco seedlings the remainder of the year, utilizing solar energy for greenhouse heating. Weather variability, being an integral part of the total system operation, was incorporated into an on-line decision-making process to achieve maximump erformance. A microprocessor-based control system was designed to manage the solar collection and air heating through airflow control within the collector. Solar tobacco curing was performed, the first time under microcomputer control. Full-scale tobacco cures and greenhouse seedling production demonstrated quality tobacco curing with over 50% fuel savings and provided high germination rates of 95%, 97% with healthy seedling growth.

Units: Dual