Regardless if a PV manufacturer produces solar cells by itself or purchases the cells from another manufacturer, proper solar cell sorting is an important first step in the manufacturing process.
For the majority of PV manufacturers for example in China, solar cell sorting is done manually.
Why is solar cell sorting important?
The first step in the process of solar cell sorting is the visual check.
During this step, solar cells with any kind of visual defects will be eliminated.
Besides that the cells will be categorized according to solar cell color.
Depending on how strict the solar cell sorting is conducted - subject to the internal quality standards - the quality control team of our partner KISUN Solar regularly finds solar panels that have cells with visual defects.
After any damaged / chipped/ color-deviating cells are identified and put aside, the solar cells will be tested with an efficiency tester and categorized according to cell efficiency.
Defect solar cells: what do manufacturers do with it?
Mainstream quality demand in Europe and the United States requests perfectly looking solar panels.
Therefore, for A-grade solar panels only flawless cells can be used.
But what do to with B-grade cells or slightly broken cells that can not be used for this purpose?
Off-Grid solar panels
The solar cells with a slight breakage can be cut with a laser cutter, and after cutting be re-used for smaller (often: off-grid) solar panels.
Good manufacturers have on average around 1-3% breakage rate during production, so there are plenty of broken cells available that can be used for small solar panels.
Solar cells are expensive and nothing needs to be thrown away!
Don't let the look of a B-grade solar cell mislead you: very often solar cells with slight visual problems do perform very well, and the solar panels made of it are good value for money.
B-grade panels are popular all around the world and when looking for the best price / watt ratio solar panels, this is probably what those customers end up with.
The key in purchasing B-grade panels is to know exactly what to buy. A trip to the manufacturer and its factory would be recommended in this case.