Though the journey towards sustainable energy sources is advancing, a hidden challenge known as the hotspot effect on solar panels can cast shadows on the efficiency of photovoltaic systems. This article will provide details on solar panel hotspots, their causes and effects, and how to prevent them.
What are Hotspots in Solar Panels?
The solar system has a complex structure, with each module comprising intricately engineered and electrically connected solar cells. The bond between each cell/ module allows the forward flow of current. However, when one or more cells in a string cannot produce enough current, the situation is known as the hotspot effect.
This effect could be due to the decline of sunrays in the solar panel through tree branches, dust, buildings, or other factors.Â
How to Detect Solar Panel Hotspots?
Solar panel hotspots are usually not visible to the naked eye, but that doesn’t mean they’re not there. It may either appear as noticeable damage on the surface or as a visible brown spot on the solar panel. A good way to detect them is through thermography.
Thermography is a safe diagnostic tool that consists of a thermal camera to help identify overheating components and lines in the electric panels, cells, or modules.
What Causes Hotspots on Solar Panels?
When an enormous power distribution happens in a small area, which leads to overheating or hotspots, this could, in turn, lead to the degradation of solar cells, melting of solder, or glass cracking.
Below are the causes of solar panel hotspots,
- Soiling/ Shadowing: Surface foiling, foreign objects on the surface, bird pooping, dirt, mud accumulated on the corners of panels, and overhead objects such as overhanging tree branches, poles, vegetation, water tanker, or other objects.
- Mechanical Damage: Improper fixturing of cells, broken glass, bent frame, and collisions of modules with other objects.
- Internal Module Failures: Poor solder joints, low-quality de-lamination, defective cell materials, and cell or glass cracks occurred during manufacturing, transportation, or installation.
- External Factors: These are caused by weather conditions such as lightning, extreme heat or cold temperatures.
How to Prevent Hotspots in Solar Panels?
The effects of the hotspot in solar panels can be prevented with some system design enhancements and regular maintenance. Below are the three critical factors that will help prevent solar panel hotspots and ensure solar panel efficiency.
Site Testing and Inspection
The first and foremost factor should be considered while deciding on the site location. A complete study and site testing are mandatory before installing your solar panels. This testing will allow installers to spot any barriers or obstructions, such as water tanks, trees, electric poles, etc., which might cast shadows on the solar panels. To avoid shadings and ensure it doesn’t affect the performance of panels, the installer can go for module-level smart electronics.
The second factor to look at is site inspection. This will help developers understand the weather conditions the site is prone to, such as lighting, hailstorms, or rainfall.
Regular Maintenance
It is crucial to clean the solar panels every two weeks to ensure they are free of dust, dirt, or bird droppings because a soiled panel can increase the risk of hotspots and also reduce the power output.
Modules with Air Flow Underneath
Industrial solar panels are usually installed in areas which absorb heat much faster. This is why, during rooftop installations, one must ensure there is enough space between and underneath the solar panels.
Power generation in solar photovoltaic systems is indirectly proportional to the solar panel’s temperature. Hence, in extreme heat, solar energy output goes down. Hotspots are generally developed because of overheating. So, leaving space for air circulation can significantly reduce the effects of hotspots on solar panels.
Solar panel hotspots can have a severe effect on the solar panel’s performance when not maintained. However, regular maintenance and efficient system design can ensure your PV systems operate at a rated capacity.
