Abstract
This research is carried out to provide fundamental data for the design of solar photovoltaic systems. Methodologically, the solar radiation installations from 10 different pyreheliometers are measured, which are set up at 6 and 4 different levels of tilts and azimuth, respectively. Maximum of a yearly accumulated solar radiation is $1,569.8kWh/m^2{\cdot}year$ with a tilt angle of $30^{\circ}$ and an azimuth angle of $0^{\circ}$(south), $1,558.5kWh/m^2{\cdot}year$ with an azimuth angle of $0^{\circ}$(south) in combination of a tilt angle of $35^{\circ}$. This paper estimates that in designing fixed solar photovoltaic systems with a tilt angle of $12.5^{\circ}{\sim}50^{\circ}$(south) and a tilt angle of $35^{\circ}$ in combination of an azimuth angle of $S45^{\circ}W{\sim}S45^{\circ}E$, a tilt angle and an azimuth angle will cause a maximum 6.8% and 9.9% of efficiency variation respectively, depending on a installed solar module's angle and direction.
