Solar Drying System for Agricultural Waste Sludge (Part 3) Solar photovoltaic system and its operation

• Published in: Nogyo Shisetsu (Journal of the Society of Agricultural Structures, Japan) Vol. 27; no. 2; pp. 77 - 84
• Main Authors: TOJO, Seishu, WATANABE, Kengo, KURODA, Hiroaki, SRIARJ, Mathanee, KATO, Makoto
• Format: Journal Article
• Language: English; Japanese
• Published: The Society of Agricultural Structures, Japan 25.09.1996
• Subjects: drying; electric energy; sludge; solar photovoltaic; solar photovoltaic generation; solar thermal energy
• ISSN: 0388-8517; 2186-0122
• DOI: 10.11449/sasj1971.27.77

Solar photovoltaic (PV) generating system was discussed for supplying the electricity to the electric devices of the solar sludge dryer in this paper. The cost of PV module will be still higher if the PV system is designed according to the installation manuals because the PV capacity is calculated with an average of solar irradiation. To reduce the initial cost of PV system, the area of PV array may be smaller than the standard installation. The followings are affirmed through the experiments on PV output characteristics, solar drying of brewer's grain waste and the operating simulation of the solar dryer. 1. Maximum output of PV module is proportion to radiation incident upon the module. Amount of electricity generated in PV can be predicted if the radiation incident upon the module is calculated. The electric generating efficiency of PV module depends on the terminal voltage of the battery because the PV output changes with the acting voltage. 2. The PV electric system should have a battery to allow the night operation and the smooth action of the motor that needs a strong starting torque. The battery can supply the electricity to the load in the case of continuous bad weather. 3. The electric power required to the electric load depends on the drying sludge mass. To simulate the electric power balance, a simulation model of the PV generating system including the solar drying process should be developed. 4. The minimum area of PV module might be three times larger than the standard in the independent electric power system. To avoid the surplus installation, or, to save the cost of PV module, the operation method, as the fan stops in the night and a lower radiation day time, should be discussed for the system design.