How to calculate the installation angle of the solar panel square array?
Because solar energy is a clean energy source, her applications are growing rapidly around the world. The use of solar power is a way of using solar energy. At present, the cost of building a solar power system is relatively high. Therefore, in order to more fully utilize solar energy, how to select the solar cell array angle and tilt angle is a very important issue.
Azimuth
The azimuth of the solar array is the angle between the vertical plane and the south direction of the square matrix (set to a negative angle to the east and a positive angle to the west). In general, when the square array is facing south (that is, the angle between the vertical plane of the square array and the south is 0°), the solar cell power generation is the largest. When deviating from Zhengnan (Northern Hemisphere) by 30°, the power generation of the square matrix will be reduced by about 10% to 15%; when deviating from Zhengnan (Northern Hemisphere) by 60°, the power generation of the square matrix will be reduced by about 20% to 30%. However, in the clear summer, the maximum moment of solar radiant energy is later at noon, so when the orientation of the square matrix is slightly westward, the maximum power generation can be obtained at noon. In different seasons, the orientation of the solar cell array is slightly higher in the east or west. The location of the square array is subject to many conditions, such as the azimuth of the land when it is placed on the ground, the azimuth of the roof when it is placed on the roof, or the azimuth when it is used to avoid the shadow of the sun, as well as layout planning and power generation. There are many factors related to efficiency, design planning, and construction purposes. If you want to adjust the azimuth to coincide with the peak time of the load during the day, please refer to the formula below. As for the field of grid-connected power generation, we hope to consider the above aspects to select the azimuth. Azimuth = (peak time of day load (24-hour system) -12) × 15 + (longitude - 116) The relationship between the amount of solar radiation and the passage of time when the solar cell array in Beijing is at different azimuths on October 9. In different seasons, the peak generation time of each solar radiation is different.
2. Tilt angle
The tilt angle is the angle between the square plane of the solar cell and the horizontal ground, and it is hoped that this angle is the optimal tilt angle when the power generation is maximum in a square matrix in one year. The best tilt angle of the year is related to the local geographic latitude. When the latitude is high, the corresponding tilt angle is also large. However, as with the azimuth, restrictions on the inclination angle of the roof and the inclination angle of the snow slip (50%-60% of the slope) are also considered in the design. For the slope angle of snow falling, even if the amount of power generation during the snow period is small and the total annual power generation is increased, especially in the system of grid-connected power generation, the slippage of snow is not necessarily given priority. Further consideration of other factors. For Zhengnan (azimuth angle is 0°), when the inclination angle starts from the horizontal (inclination angle of 0° degree) and gradually transitions to the optimum inclination angle, the amount of solar radiation increases continuously until the maximum value, and then the inclination is increased. The amount of solar radiation is decreasing. In particular, after the inclination angle is greater than 50° to 60°, the amount of solar radiation drops sharply, and the power generation amount is reduced to the minimum until the last vertical placement. There are practical examples of square arrays placed vertically from 10° to 20°. For the case where the azimuth angle is not 0°, the value of the slanted solar radiation amount is generally low, and the value of the maximum solar radiation amount is near the inclination angle close to the horizontal plane. The above is the relationship between azimuth, tilt angle and power generation. For the specific design of the azimuth and tilt angle of a square matrix, it should be comprehensively combined with the actual situation.
3. The effect of shadow on power generation
Under normal circumstances, when we calculate the amount of power generation, we get it under the premise that the square front has no shadow at all. Therefore, if the solar cell cannot be directly illuminated by sunlight, then only the scattered light is used to generate electricity, and the amount of power generation at this time is reduced by about 10% to 20% compared with the unshaded. In this case, we need to correct the theoretical calculations. Usually, when there are objects such as buildings and mountains around the square, when the sun comes out, there will be shadows around the perimeter of the building and the mountain. Therefore, you should try to avoid the shadow when you choose to lay the square. If it is really impossible to avoid, it should also be solved from the wiring method of the solar cell, so that the influence of the shadow on the power generation is reduced to the minimum degree. In addition, if the square matrix is placed before and after, the distance between the rear square matrix and the front square matrix is close, and the shadow of the front square matrix will affect the power generation of the latter square matrix. There is a bamboo pole with a height of L1. The shadow length of the north-south direction is L2, the height of the sun (elevation angle) is A, and when the azimuth angle is B, assuming that the magnification of the shadow is R, then:
R=L2/L1=ctgA×cosB
This type should be calculated on the day of the winter solstice, because the shadow of the day is the longest. For example, the height of the upper edge of the square matrix is h1, and the height of the lower edge is h2, then the distance between the square arrays is a=(h1-h2)×R. When the latitude is high, the distance between the squares is increased, and the area of the corresponding place is also increased. For square arrays with anti-snow measures, the angle of inclination is large, so the height of the square matrix is increased. To avoid the influence of shadows, the distance between the square arrays is correspondingly increased. Generally, when arranging the array of square arrays, the structural size of each square matrix should be selected separately, and the height should be adjusted to an appropriate value, so that the distance between the square arrays can be minimized by using the height difference. The specific solar cell array design, while reasonably determining the azimuth and tilt angle, should also be considered comprehensively, in order to achieve the best state of the square array.