Recently consulting the photovoltaic power plant power generation problems more and more partners, I collected some of the most can affect the photovoltaic module power generation factors, I hope to help you!
1, component quality
Due to the cell hidden crack, black heart, oxidation, false welding, as well as the backplane and other material defects and long-term use of aging and other factors, resulting in the module in the long-term operation of the process of power is affected, resulting in low component power generation. It is worth noting that the crystal structure of monocrystalline determines its superior performance in anti-cracking.
2、PID effect
In the long-term work of the module in the outside world, due to the penetration of water vapor through the backsheet to the inside of the module, causing EVA hydrolysis, acetate ions to precipitate metal ions in the glass, resulting in the existence of high bias voltage between the internal circuit and the frame of the module and the electrical performance decay and a sharp drop in power generation.
3、Mounting method
From the total amount of solar radiation on the tilted surface and the principle of direct scattering of solar radiation separation can be obtained: the total amount of solar radiation on the tilted surface Ht is composed of direct solar radiation Hbt sky scattering amount Hdt and ground reflected radiation Hrt, that is: Ht=Hbt+Hdt+Hrt. On the same geographical location, due to the different installation inclination of the module, the accumulated amount of sunlight absorption is different, the accumulated difference of radiation The cumulative difference in the amount of radiation caused by the difference in power generation.
4、Weather factor
Weather is also one of the factors affecting the power generation efficiency of the components. When it is rainy and cloudy, the intensity of sunlight irradiation decreases, the cell absorbs less sunlight, and the power generation decreases, and the weak light response of monocrystalline is better than polycrystalline under low irradiation. Under the condition that the conversion efficiency of solar cell module is certain, the power generation of PV system is determined by the radiation intensity of the sun. The power generation of photovoltaic power plant is directly related to the amount of solar radiation, and the radiation intensity and spectral characteristics of the sun are changed with the meteorological conditions.
5、Shadow shading
Due to the partial shading of the module in the working process, as well as the varying degree of dust settlement and bird droppings pollution will cause the "hot spot effect", the shaded part of the module will not provide power contribution and become energy-consuming load inside the module, while causing the local temperature of the module to rise, the overheated area can cause EVA to accelerate aging and yellowing, so that the area The overheated area can cause EVA to accelerate aging and yellowing, so that the light transmission rate of the area decreases, thus further worsening the hot spot, leading to increased failure of solar modules.
6、Temperature coefficient
The temperature coefficient of crystalline silicon cells is generally -0.4% to -0.45%/°C, and the temperature coefficient of single crystal is less than that of polycrystalline. Changes in external ambient temperature and the heat generated by the module in the course of work causes the temperature of the module to rise, which will also cause the module's power generation power to drop.
7、Clean maintenance clear
The components are in the field for a long time, dust and other debris will land on the glass, a large amount of long-term dust or sand settlement, weakening the penetration of sunlight, while causing the surface temperature of the components to rise and thus affect the efficiency of the components power generation. When the dust on the module surface is serious, the difference between the power generation before and after cleaning is 5.7%, and the difference in power generation can be more than 10% if no cleaning is done on the module surface for a long time.
In addition to the above-mentioned factors, there are other factors such as power attenuation and power generation reduction during the working process of the module due to the electrical system and other factors, which are subject to process improvement, technology enhancement, material development and more relevant research to solve and improve the factors affecting module power generation. The subsequent process improvement, technology enhancement, material development and more relevant research are needed to solve and improve the factors that affect the power generation.
