People knowing not so much about PV power plants may easily belive that “Since the summer sunshine hours are long and sufficient, and the output of the PV power station in summer must be largest." But in fact, sorting the outputs of of distributed photovoltaic power plants in four seasons from large to small,the order will be spring, autumn, summer, and winter.

Although the summer is sunny, the summer's high temperature, high humidity, heavy rainfall, and severe weather are relatively frequent. These unique summer factors will have a certain impact on the power generation of the power station. The amount of electricity generated by the PV power plant during a day is related to the local sunshine intensity, the orientation of the components, the installation inclination and the seasonal weather conditions.

In summer, the negative factor is high temperature, which affects the modules and inverters. The peak temperature coefficient of the photovoltaic modules is about -0.38~0.44%/°C, that means if the temperature rises, the power generation of the photovoltaic modules drops. Theoretically, the power output drops 0.44% for each degree of the temperature increase.

Although the loss is only a "negligible" point compared to the electricity generated by the power station every day, but over time the accumulative loss is too huge to be neglected. Moreover, in addition to affecting the amount of power generated, the continuous high temperature will cause the equipment failures and even fires. Of course, the probability of such is small, but it does not rule out the unexpected situation.

Whilst the temperature in spring and autumn is suitable, and the photovoltaic power station is rarely affected by bad weather. The power generation of the power station during the day will be more stable and sufficient.