SunPower Solar Cells are quickly gaining popularity, and as more people are looking into it for potential buying opportunities, they might be surprised by the way SunPower grades its cells.
The solar cell grades range from Grade A to L. However, be wary as Grade A is not the highest grade, it is, in fact, the lowest grade.
The highest grade is Grade L.
As you can see in the table above in the SunPower Prime pricelist, the only three grades available for sale are; Ultra Premium Performance(L)(23.7%), Ultra High Performance(K)(23.1%), Ultra Performance(J)(22.6%), with their efficiency evidently decreasing from L to J.
For example, one common practice, unfortunately, is for certain resellers to buy cheap and low-quality Grade A SunPower cells for 1USD/Watt on the Chinese market, and sell them on Amazon for 150-170USD/100W.
They are deceitfully marketed as top-quality cells, and non-surprisingly problems start to arise around one year after purchase.
When it comes to buying stuff from China, “you get what you paid for” is generally good advice to follow.
There’s always a drawback to buying something for cheap, although it might not be too apparent at the beginning.