Hot-spots on solar panels. How to prevent them?
Dodane przez: admin March 16, 2022
The resistance of PV panels to mechanical damage is today one of the key selection factors for the customer, and thus one of the most important aspects that manufacturers focus on. In practice, however, despite their great efforts to increase the durability of products, photovoltaic modules are still highly susceptible to microdamages, i.e. defects that are often almost or completely invisible, and yet have a negative impact on their operating efficiency. These types of flaws, apart from lowering the efficiency of the installation itself, under certain conditions may also lead to serious failures in the form of the so-called hot-spot effect. Photovoltaics is an area to which we approach fully comprehensively, so in this post we will discuss this problem in detail.
What is a PV hot-spot and from what factors can photovoltaic panels self-ignite?
The hot spot effect or the hot-spot effect in photovoltaic panels occurs in quite specific circumstances, under which a photovoltaic cell with microcracks will be in a shaded area.
The standard reaction of the system to such circumstances is the occurrence of the reverse current flow process through insufficiently lit cells. While in the case of fully operational and undamaged cells it would not have very serious consequences (although it would still be harmful), in the case of defective cells it may lead to their excessive heating. The consequence of such a state of affairs is often further degradation of the damaged module, and in extreme cases even self-ignition of photovoltaic panels. According to some producers of PV installations, the area with a hot spot can reach a temperature of more than 250 ° C.
Hot-spot photovoltaics and production, transport and installation
Since we have already explained how a damaged photovoltaic panel affects the PV hot-spot effect, it is worth mentioning a few more words about the sources of this type of minor material defects.
During the production of solar panels, they are constantly influenced by a wide variety of factors, including the presence of high temperatures, contact with various types of chemicals or the effect of mechanical stress of high intensity. Even with highly optimized and efficiently performed industrial processes, these stimuli can still lead to minor cracks and micro-flaws that are extremely difficult to detect with conventional quality control. This, in turn, means that the damaged photovoltaic panel can be left at the start of the factory walls. Another source of PV hot-spot defects may also be the lack of adequate protection during transport, as well as improper installation.
Hot-Spot Protect marking and other factors to eliminate the hot-spot in photovoltaic panels
After the earlier, quite negative part of the post, it is worth cooling down the emotions and pouring some optimism into it. First of all, when it comes to the hot-spot effect, photovoltaics in the modern edition notices it very rarely, if only because even the smallest level of shading should not occur at all in the case of a properly installed PV system, so no professional company will put its client at risk this key element of risk in relation to the formation of hot spots.
When discussing the topic of counteracting hot spots, it is also worth mentioning that self-ignition of photovoltaic panels would be a huge loss of image for both their producer and the company that undertook the comprehensive implementation of the entire solution, so these situations are also very rare.
Nevertheless, when investing a lot of money in a PV installation, it is worth protecting yourself against any eventuality. Therefore, in order to reduce the risk of the hot-spot effect in photovoltaic panels, it is worth choosing devices marked as Hot-Spot Protect (HSP) in the first place. If we already have an implemented system that has not been labeled with the HSP mark, we can outsource a thermovision inspection to an external servicing company to detect potential hot spots.
In addition, during the installation, transporting or willing to repair a damaged photovoltaic panel, you should only use the services of highly qualified specialists, bearing in mind that even the perfect condition of the device and the Hot-Spot Protect label declared by the manufacturer will still not protect us 100% against microcracks that may arise as a result of mechanical damage or improper service.