Why is summer not the season with the highest photovoltaic power generation?
High temperature causes component power attenuation
TestPV learned that when the photovoltaic module is working normally, the standard operating temperature of the cell is 25 ° C. Under operating conditions greater than 25 ° C, each time the temperature rises by one degree, the output power of the component will cause corresponding attenuation. At this time, the power generation of the photovoltaic module is affected by the temperature coefficient of the photovoltaic module.
Normally, every 1 ° C increase in battery cell temperature. The output power of the N-type single crystal module is reduced by 0.38% of the reference value. The output power of the P-type component is reduced by 0.42% of the reference value.
The researchers conducted relevant experiments on the effect of temperature on power generation performance. The data shows that when the temperature change range is -3.15 to 66.85 ℃, the conversion efficiency temperature change rates of single-crystal silicon solar cells and polycrystalline silicon solar cells are -0.176% / ℃ and -0.08% / ℃, respectively.
Previously, a photovoltaic worker tested the indicated temperature of the photovoltaic module when the outside temperature was as high as 40 ° C in July, reaching as high as 57.5 ° C, and the temperature of the backplane reached 63 ° C. From this, the attenuation caused by high temperature in summer is calculated to be about 15%.
Component hot spots cannot be ignored
Also worth preventing is the local high temperature caused by hot spots of components. The light affects the battery life, and even more serious can even cause a fire.
When referring to the hot spot of the module, it can not be ignored that the mud spot zone is blocked by the incident light along the lower part of the module, so that the current in this area is significantly smaller than that in other non-mud zone areas. The hot spot generated in the dust deposit is an important factor that reduces the power generation of photovoltaic modules.
How to maintain the power generation during the high temperature period in summer has become a top priority for photovoltaic power plants. And it is rainy in summer, you may wish to start from the accumulation of components.
The roof projects of industrial plants are mostly around one megawatt, and the annual power generation is one million kWh. Generally, the accumulation of dust on the surface of the module will cause a loss of 10% or more in power generation. However, the impact of floating ash is not so great. Many operation and maintenance data reflect that the benefit of cleaning on module power generation is about 3-5%. Therefore, the biggest culprit for the loss of electricity generated by modules is the mud belt. Mud belts that are difficult to remove and can affect the power generation of the entire module.
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