The hotspot is one of the most dangerous problems that can arise in aphotovoltaic moduleIt is a point on the solar panelthat overheats producing a single area of high temperature, this generates a localized decrease in efficiency, in addition to a greater degradation of the materials in that area reaching the point of being able to damage that part of the module or in extreme cases cause a fire.

What does a hotspot produce in a PV module?

The hotspot is produced by a high resistance at a specific point of the solar module. The affected area becomes a consumer of energy that is dissipated, instead of generating it as normal, due to the inverse voltage that is caused, this produces a heat that will be greater the greater the irradiation on the rest of the panel, and can reach temperatures that can exceed 200ºC.

The factors for these hotspots and this inadequate resistance are diverse, from cell mismatches, when cells of different currents are connected in series, poor welding and photovoltaic panelquality in general, micro-cracks produced in transport or installation, shadows produced by dirt, droppings, trees or other elements.

What are the effects of a hotspot on a PV module? 

Hotspots are generally quite unstable, which means that they will gradually intensify until they reach a point where they cancel out the total performance of the PV module.

Once the hotspot is created, the effects that can be produced depend on the duration of the hotspot; the longer it is delayed, the greater the damage to the solar panel. It can break the point of contact softening the insulating material, ignite the materials or produce an electric arc. All of this can cause a loss of performance, render the module unusable or even cause a fire.

How to avoid a hotspot on a PV module?

This problem can occur throughout the lifetime of the solar panel since triggers can occur at any time. 

To prevent this problem from appearing, we can follow a series of tips:

• Purchase photovoltaic modules from quality brands that ensure proper manufacturing to avoid manufacturing defects that can lead to hotspots.

• Proper transport to avoid micro-breaks that could lead to hotspots that could create major problems.

• Correct handling of the photovoltaic module during installation to avoid breakage or damage that could cause this problem.

• Study the location and placement of the panels in places where they do not suffer shadows that could produce hotspots.

• Perform regular maintenance of the panels to ensure that there is no accumulation of dust or dirt that can create persistent shadows.

• Monitor the installation for possible incidents that indicate that hotspot or other problems may be generated.