*G.I.K. Institute of Engineering Sciences and Technology, Topi, NWFP, Pakistan
**Physical Technical Institute of Academy of Sciences, Rudaki Ave,33, Dushanbe, Tajikistan.
ABSTRACT
This paper describes the design and investigation of a photo-voltaic system with variable solar modules inclination angles. The current-voltage (I-V) characteristics of a single crystal module are investigated under natural conditions. The PV system contains 180 modules of area of 0.37-0.39m2. The inclination angle of each module with the horizontal plane was 23o, 34o and 45o. The latitude of the PV stations location is 34o N. Investigations were performed on clear and variable cloud days. An increase of 12-19% in the produced electrical energy is observed with an increase in the inclination angle in the winter period i.e. February 2009. The efficiency of the modules was in the range of 11%-12% at the change of inclination angles. A simple PV modules support was designed in order to easily change the modules inclination angle. The total numbers of the supports were 34 and on each support 5 to 6 modules were installed. Approximately one and one half hour was necessary to change the inclination angle of all the modules seasonally.
Keywords: Photovoltaic power system, module, variable inclination angle, current-voltage characteristics, efficiency.