Solar panel hotspots: How & What?
A hotspot is typically caused by dirt or concentrated shading in one area. For a hotspot to occur, all the cells must receive a certain amount of sunlight.
Typical causes of hotspots include bird droppings, a fallen leaf, or concentrated shading from a thin pipe on the roof or a lightning rod fin.
While a hotspot is not ideal, it doesn't always result in damage. The cell only becomes hot while the cause of the coverage or shadow is present. Once the bird droppings or leaf are washed off, the cell will function normally again. However, a hotspot that persists or frequently recurs can eventually lead to permanent damage.
When multiple cells are shaded or covered in dirt, the chances of hotspots are much lower; in those cases, the electricity will be redirected through the bypass diodes in the panel.
Thanks to our rainy climate, dirt is usually washed off the panels naturally. The greatest risk of a harmful hotspot comes from concentrated shading on one cell, especially when the other cells are fully exposed to sunlight. This can happen with thin objects that are positioned directly south of the panels, such as lightning rod spikes.
In terms of the severity of hotspots, not all panels are the same: The cells in SunPower panels have a lower ‘reverse bias voltage’ than standard solar cells. This means that a hotspot in a SunPower cell becomes less hot than a standard cell. Less heat means less chance of damage. Combined with the superior quality of SunPower panels, these panels are much less likely to experience lasting damage from a hotspot.
Our advice: Avoid concentrated shading from narrow or small objects that are south of the panels. If possible, move lightning rod antennas, and consider installing SunPower panels. However, know that most hotspots resolve on their own and do not lead to major issues!
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