There is a close relationship between the optimal inclination angle of solar bracket and latitude, and this relationship is mainly reflected in the following aspects:

Basic rules

The optimum inclination angle of a PV mount is usually related to the local geographic latitude. As the latitude increases, the optimal inclination angle increases accordingly. For example, when the latitude is between 0° and 25°, the optimal tilt angle is equal to the latitude; when the latitude is between 26° and 40°, the optimal tilt angle is the latitude plus 5° to 10°; when the latitude is between 41° and 55°, the optimal tilt angle is the latitude plus 10° to 15°; when the latitude is over 55°, the optimal tilt angle is the latitude plus 15° to 20°.

Seasonal Adjustment

The variation of solar altitude angle in different seasons has an important effect on the optimal tilt angle. For example, during the spring and fall equinoxes, when the sun's point of direct incidence is located on the equator, the optimal tilt angle of the PV panels is close to the local latitude; while during the winter and summer solstices, when the sun's point of direct incidence is shifted to the southern hemisphere and the northern hemisphere, respectively, the optimal tilt angle needs to be adjusted accordingly to adapt to the change of the sun's angle of incidence.

Adjustment in practice

In practical applications, the optimal inclination angle may deviate due to the limitations of terrain, climate conditions and installation conditions. For example, in high latitude areas, the sunshine time is short in winter and the solar altitude angle is low, so the inclination angle needs to be increased to improve the power generation efficiency; while in low latitude areas, the solar altitude angle is high in summer, so the inclination angle can be reduced appropriately.

Different types of mounting systems

Fixed PV mounts and adjustable PV mounts differ in their optimal inclination. Fixed mounts typically use an inclination close to the local latitude, while adjustable mounts allow for seasonal adjustments to maximize year-round power generation. Studies have shown that PV systems with adjustable mounts have less variation in power generation between seasons, whereas fixed mounts may lose some of their radiation in the summer due to excessive inclination.

Special Case Analysis

In some special areas, such as Golmud (19.6°) in Qinghai, Dunhuang (18.7°) in Gansu, and Ganzi Prefecture (18.9°) in Sichuan, the optimal inclination angles derived from regression analyses were 19.6°, 18.7°, and 18.9°, respectively. These data indicate that the optimal inclination angle needs to be optimized in relation to the local solar radiation intensity and geographical environment.

Other influencing factors

In addition to latitude, other factors such as direct-to-diffuse ratio (the ratio of direct to scattered radiation), wind load, snow load, etc. also affect the selection of the optimum inclination angle. For example, in areas with high wind speeds, it may be necessary to select a smaller inclination angle to increase the wind resistance of the solar stand.