How to choose the inclination of solar modules

When designing the inclination of the photovoltaic array, there is a big difference between the grid-connected power station and the off-grid power station, because the goals pursued by the grid-connected power station and the off-grid power station are different when generating electricity.

The goal of grid-connected power stations is to maximize the annual power generation, that is, the design of the inclination angle of the power station should comprehensively consider the power generation situation of each month throughout the year. For areas with good solar radiation resources, the inclination angle of the photovoltaic support should be roughly the same as the local latitude angle. For areas with general solar radiation resources or areas with high air humidity and more cloudy and rainy days, due to the large solar scattered radiation, the contribution of scattered radiation to power generation should be fully considered in the design of the inclination angle of the photovoltaic support, and the support inclination should be designed to be slightly lower than the local latitude.

That is to say, for grid-connected photovoltaic power stations, the inclination angle of the photovoltaic array support is usually designed to subtract 0-8 degrees from the local geographic latitude angle. The specific degree of subtraction depends on the local sunny index. The clearer the area, the smaller the subtracted angle; the more rainy area, the larger the subtracted angle, try to place the photovoltaic modules horizontally, you can get more scattered radiation.

For off-grid photovoltaic power plants, the goal of power generation is not to maximize the power generation throughout the year, but to meet the needs of the load every month. Usually, the load of off-grid power plants is relatively fixed, and the monthly solar radiation varies greatly. For example, in summer, the days are long and the solar radiation is good, while in winter the days are short and the amount of solar radiation is small, so there will be a problem: : In summer, the photovoltaic system generates too much power, and the consumption will cause waste. In winter, the power generation may not be enough due to weak solar radiation.

To solve this problem, the inclination angle of the bracket is usually designed to be slightly higher than the local geographic latitude angle in the design of the power station bracket (because the incident angle of solar radiation in winter is low, increasing the bracket inclination can improve the power generation of photovoltaic arrays in winter), In this way, more consideration can be given to the power generation of the photovoltaic system in winter.

Therefore, for different types of photovoltaic power plants, the bracket inclination design is different. In the project design, all factors should be fully considered to select the best solution.