Views: 0 Author: Site Editor Publish Time: 2022-03-29 Origin: Site
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With the advancement of photovoltaic production technology and the support of government policies, more and more families have begun to install solar system on their roofs. But in the process of PV power generation, many users have discovered why the same number of PV modules generate different amounts of power in the same time period? Don't worry, you will understand after reading this popular science post.
What is the reason for the difference in power generation?
01. Environmental factors
The light conditions (solar resources) are different in different regions, and the power generation is naturally high in regions with superior solar resources.
Generally speaking, my country is a region rich in solar energy resources, but there are still great differences in solar energy resources in different regions.
The northwestern regions such as Tibet, Qinghai, and Gansu are the regions with the most abundant solar energy resources in my country and are classified as a first-class region; Shandong, Henan, southeastern Hebei, southern Shanxi, northern Xinjiang, Jilin, Liaoning, Yunnan, northern Shaanxi, southeastern Gansu, Guangdong Southern, southern Fujian, central and northern Jiangsu and northern Anhui are the second-class areas with abundant solar energy resources; parts of the middle and lower reaches of the Yangtze River, Fujian, Zhejiang and Guangdong are the third-class areas with general solar energy resources; Sichuan and Guizhou provinces are solar energy resources. The least four categories of areas.
In this way, it is not difficult to understand why the power generation of Lao Li in Gansu is larger than that of Lao Wang in Jiangsu.
02. Installation angle of PV module array
When installing the PV module, it should be installed in the direction with the most sunshine , and the installation inclination is generally determined by the latitude of the installation site, and there are slight differences in each region. Assuming that the efficiency of the optimal installation angle is 100%, the efficiency of installing PV modules at different orientations and angles is shown in the following figure:
03. Quality of solar system
The solar energy conversion rate of high-quality solar products is significantly higher than that of inferior products.
Next, I will teach you a few tricks to increase photovoltaic power generation
01. The inclination of the installation of photovoltaic modules
The azimuth angle of photovoltaic modules is generally selected in the south direction(take the north hemisphere as sample), so as to maximize the power generation per unit capacity of the photovoltaic power station. As long as it is within ±20° of due south, it will not have much impact on power generation. If conditions permit, it should be 20° southwest as far as possible.
02. PV module efficiency and quality
Calculation formula: theoretical power generation = total annual average solar radiation × total solar cellarea × photoelectric conversion efficiency
There are two factors, solar cell area and photoelectric conversion efficiency. The conversion efficiency here has a direct impact on the power generation of the power station.
Component matching loss
Any series connection will cause current loss due to component current differences, and any parallel connection will cause voltage loss due to component voltage differences. Losses can reach more than 8%.
Ensure good ventilation of components
According to the data, when the temperature rises by 1°C, the maximum output power of the crystalline silicon PV module group decreases by 0.04%. Therefore, it is necessary to avoid the influence of temperature on power generation and maintain good ventilation conditions. The loss of dust should not be underestimated. The panel of the crystalline silicon module is tempered glass. If it is exposed to the air for a long time, organic matter and a large amount of dust will naturally accumulate. The dust on the surface blocks the light, which will reduce the output efficiency of the module and directly affect the power generation. At the same time, it may also cause the "hot spot" effect of the components, resulting in damage to the components.
03. Reduce line loss
In a photovoltaic system, cables account for a small part, but the influence of cables on power generation cannot be ignored. It is recommended that the line loss of the DC and AC circuits of the system be controlled within 5%.
The cables in the system should be done well, the insulation performance of the cable, the heat-resistance and flame-retardant performance of the cable, the moisture-proof and light-proof performance of the cable, the type of the cable core, and the size of the cable.
04. Inverter efficiency
The photovoltaic inverter is the main component and important component of the photovoltaic system. In order to ensure the normal operation of the power station, the correct configuration and selection of the inverter is particularly important. In addition to the configuration of the inverter, in addition to the technical indicators of the entire photovoltaic power generation system and the product sample manual provided by the manufacturer, the following technical indicators should generally be considered.
(1) Rated output power
(2) Adjustment performance of output voltage
(3) The efficiency of the whole machine
(4) Startup performance
In general, my country (China)is rich in solar energy resources, and most regions are suitable for installing photovoltaic power generation, but when choosing to install photovoltaics, the subtle factors of photovoltaic brand and component quality should be considered. In the specific installation process, it is also necessary to choose the best installation angle according to local conditions to obtain the maximum power generation. Only in this way PV can maximize its value and create better value for users.
