The surface of the monocrystalline silicon solar panel is ultra-white tempered glass, so the solar panel has a strong impact resistance, but this is not absolute. If it encounters a large hail that occurs in a hundred years, it may also damage the surface of the solar photovoltaic panel.

How to check whether hail damages the solar panel?

Under normal circumstances, PV modules from regular manufacturers have passed professional tests and certifications, such as IEC 61215 certification, which includes multiple tests to ensure that the modules can withstand the impact of 35mm hail at a speed of 27.2 m/s or more than 98 kph. If the module passes the relevant tests required by IEC61215, it indicates that the module is qualified to withstand extreme weather such as hail and high winds.

But after the hail, the smashed solar panels may suffer various damages. It is good to be able to see the damage like glass, but there may be damage that is not visible to the eyes.

This time, we will introduce an example of inspection of solar panels damaged by hail.

In order to find out which battery panels have been damaged in addition to glass damage, you can use EL inspection.

Methods of checking the fault location of solar panels generally include using thermal imaging to lock the heating part, or using a disconnection detector to check the fault of the disconnected part and bypass diode.

Although these methods can lock the location of the fault, it is difficult to find out the status and cause of the fault.

The EL inspection is a method used by solar panel manufacturers in the quality inspection before supplying products.

This method can not only lock the fault location in the solar panel, but also effectively determine the cause of the fault, such as PID degradation, internal cracks, poor contact, and diode failure that occur in a high temperature and humidity environment.

However, the EL inspections so far have been carried out indoors such as factories, and have not been applied to solar panels that have been installed in photovoltaic power plants. And now this kind of inspection can be implemented at the site of the photovoltaic power station.

Use EL inspection outdoors to grasp the situation

Outdoor EL inspection has been realized with an inspection device that can obtain EL images of solar panels. Utilizing the industry's first outdoor EL inspection device launched by NPC (Arakawa Ward, Tokyo)

Here is an EL image of a solar panel that is actually installed outdoors. Both pictures are solar panels that have been hit by hail. Figure 1 is a monocrystalline silicon solar panel, and Figure 2 is an image of a polycrystalline silicon solar panel.