PV users generally believe that the high temperature and long sunshine hours in summer, the power plant power generation is relatively high, the higher the temperature the greater the power generation. But in fact, photovoltaic power plants are "afraid of heat" and "afraid of cold", extreme high and low temperatures can affect the performance of photovoltaic power generation.
Why does temperature have an impact on photovoltaic
Photovoltaic system power generation principle is the use of light irradiation semiconductor photovoltaic effect, the direct conversion of light energy into electricity. Generally speaking, good light conditions in summer do produce more electricity. However, extreme heat is a different story.
Due to the temperature characteristics of the module itself, an increase in temperature will result in a loss of output power from the module. In summer, when the high temperature is 35-40℃, the back side temperature of the module can be 50-70℃, and the working junction temperature of the cell in the module may even exceed 80℃. After exceeding the rated operating temperature, the photoelectric conversion efficiency will decrease proportionally, thus affecting the power generation efficiency.
Take the temperature coefficient of PV module power 0.4%/℃ as an example, the peak power of module at 25℃ is 300W, then the peak power loss at 80℃=0.4%/℃*(80-25)℃=22%, the peak output power=300W*(1-22%)=234W. Thus, it can be seen that the temperature rise will lead to serious output power loss of module, under the other conditions remain unchanged , which means that 22% less power will be generated.
In addition to the loss of efficiency, the temperature will also affect the long-term stability of the PV cell. High temperatures can accelerate the degradation of the materials used in the cells, resulting in a shorter system life.
Which aspects of temperature affects photovoltaic
1. leading to a decrease in the output power of photovoltaic modules
Photovoltaic modules generally have three temperature coefficients: open-circuit voltage, peak power, short-circuit current. When the temperature rises, the output power of photovoltaic modules will drop. The peak temperature coefficient of PV module is about -0.38 to 0.44%/°C, that is, the temperature rises, the power generation of PV module decreases. Theoretically, for each degree of temperature increase, the power generation of PV plant will be reduced by about 0.44%.
In the actual research case shows that the output power of crystalline silicon solar cells at a temperature of about 20 degrees is about 20% higher than that at 70 degrees. That is to say, if the location of the installation of photovoltaic power plant light conditions in general, but the average annual temperature is relatively low, its power generation is much higher than the light is too strong, the temperature is too high areas.
2. Affect the service life of the inverter and other parts.
3. Formation of hot spot effect affects component life
The local temperature is too high, will produce hot spot, affect the life of photovoltaic modules. Hot spot effect (heating spot blog link) to a certain extent will damage the solar cells, there is light from the solar cells produced part of the energy, are likely to be shaded by the battery consumption, and photovoltaic power plant hot spot effect will directly lead to a 30% shortening of the service life of photovoltaic modules, in the long run may cause the failure of the components.
During the high temperature season, PV modules are shaded by bird droppings, weeds, leaves, etc., and are prone to hot spot effect, when the local high temperature of PV modules can reach more than 100℃. The hot spot effect will reduce the performance of PV modules, which in turn will cause the loss of output power of the whole string of PV modules.
Conclusion
Temperature has a significant impact on the performance and stability of PV systems. The optimal temperature for module power generation is 24-25 degrees Celsius, and while solar radiation is best in July and August, power generation is not the highest. The highest power generation months for home PV plants are April and May.
It is important to manage this effect to maximize energy output and ensure the long-term reliability of the PV system. By understanding the relationship between temperature and PV performance and taking steps to maintain PV systems, the efficiency and effectiveness of PV systems can be optimized, making them a more attractive source of renewable energy.
As a PV module manufacturer with 15 years of experience in the industry, Maysun Solar has offices and warehouses in several countries and regions, and has established long-term and stable relationships with many excellent installers. You are welcome to contact us to get the latest module quotation or ask PV related questions.