Views: 19 Author: Site Editor Publish Time: 2022-11-11 Origin: Site
You may all find that most solar panels around us are placed at a certain tilt angle, whether on the roof or street lights. The tilt angle of solar panels is related to the local geographical location as well as latitude.
一、Reasons for solar panels to be placed at an oblique angle
Solar panels are mainly through the absorption of sunlight, the solar radiation energy through the photoelectric effect or photochemical effect directly or indirectly into electricity. That is to say, the more solar radiation a solar panel receives, the more electricity it can convert, so the output power of solar modules depends on factors such as solar irradiance and solar cell temperature.
In most areas with high latitudes, the angle of sunlight irradiation is oblique. Only by placing the solar panel diagonally in the opposite direction can the panel's light-receiving surface be as perpendicular to the sun's rays as possible, allowing the solar panel to perform at high efficiency.
At present, there are also fully automatic solar panels, which allow the panels to constantly adjust the horizontal angle as the angle of sunlight changes so that the panels are perpendicular to the sunlight from morning to night.
二、Solar panel tilt angle calculation
1、Azimuth angle calculation
The azimuth angle of the solar panel array is the angle between the vertical surface of the array and the due south direction (set to the east as a negative angle, set to the west as a positive angle). Generally, when the square array faces due south (i.e. the angle between the vertical plane of the square display and due south is 0°), the solar cell power generation is large. At a deviation of 30° degrees from due south (northern hemisphere), the power generation of the square array will be reduced by about 10% to 15%. At a deviation of 60° from due south (northern hemisphere), the power generation of the square array will be reduced by about 20-30%.
In sunny summer, the high solar radiation energy is later in the noon, so when the square array is oriented slightly to the west, large power generation can be obtained in the late afternoon. In different seasons, the orientation of the solar cell array is slight to the east or west - there are times when the power generation is high.
If you want to adjust the azimuth angle to the peak moment of load and the peak moment of power generation in a day, please refer to the following formula: Azimuth angle = (peak moment of load in a day (24-hour system) - 12) x 15 + (longitude - 116) In different seasons, the peak moment of solar radiation generation in each direction is not the same.
2、Tilt angle calculation
The tilt angle is the angle between the plane of the solar cell square and the horizontal ground, and hope that this angle is the tilt angle when the power generation capacity of the square is large in a year. The tilt angle in a year is related to the local geographical latitude, when the latitude is higher, the corresponding tilt angle is also large. However, as with azimuth, the design also takes into account constraints in terms of the tilt angle of the roof and the tilt angle of the snow slide (slope greater than 50-60%).
For due south (azimuth angle of 0 ° degrees), the tilt angle from horizontal (tilt angle of 0 ° degrees) gradually to the tilt angle of the transition, the amount of sunlight increasing until the large value, and then increase the tilt angle of its sunlight decreasing. Especially after the tilt angle is greater than 50 ° ~ 60 °, the amount of daylight drops sharply until the vertical placement, and the amount of power generation is down to small. For the azimuth angle is not 0 ° degrees, the value of oblique daylight volume is generally low, and the value of the daylight volume is near the angle of inclination close to the horizontal.
3、Shadow area influence
If the solar panel can not be directly illuminated by daylight, then only scattered light is used to generate electricity, when the power generation than no shadow it reduces about 10% ~ 20%. For this situation, we have to correct the theoretical calculation value.
Usually, when there are buildings and mountains around the array, there will be shadows around the buildings and mountains after the sun comes out, so you should try to avoid the shadows when choosing the place to put the solar panels. If it is impossible to avoid, the wiring method of the solar panel should be solved so that the shadow will have less influence on the power generation.
In addition, if the square array is placed in front and behind, after the distance between the back square array and the front square array is close, the shadow of the front square array will have an impact on the power generation of the back square array. When the latitude is higher, the distance between the squares increases, and the area of the setting place increases accordingly. For the square array with anti-snow measures, its tilt angle is large, thus making the height of the square array increase, and to avoid the influence of shadows, the distance between the square arrays will increase accordingly.
The solar panel relies on receiving solar radiation to generate electricity, and the more radiation it receives, the more power it generates, so several aspects should be considered in advance when designing the solar panel installation angle.