While solar panels are often tested using a standardized level of irradiation, the outdoor application of solar panels never involves a consistent light level.
International standards have been developed to do just that, and the electrical ratings displayed on solar panel datasheets follow these standards. Standard Test Conditions (STC) are the industry standard conditions under which all solar PV panels are tested to determine their rated power and other characteristics.
The effect of weather conditions on the performance of PV panels was demonstrated through analysing the system outputs of two existing solar PV installations. Results from both studies revealed that weather conditions, particularly rain and snow, have the most negative effect on the performance of installed PV panels in the case study area.
Five light intensity values are quickly measured each time, which are the light intensity values of four corners and their centers of the photovoltaic panel, and then, the average value is the light intensity of the photovoltaic panel surface.
Furthermore, there are also solar panels designed to work under high-intensity lighting conditions. Generally speaking, current from a solar panel decreases linearly with decreasing irradiance, while the voltage drops logarithmically. However, there is significant variation among various types of solar panel with respect to these declines.
From n-type to p-type and monocrystalline to monocrystalline, there are many different kinds of solar panels and each type of solar panel responds differently to various amounts of light intensity.