I am having solar panels installed on my house. My contractor told me that they are installing 20 Canadian Solar CS3k-325-MS panels. I just got a copy of the plants they sent to the city for their permit though, and those plans say they are installing Q.Cell Q.PEAK Duo G5 325s. Comparing the two, it looks like the Q.PEAKs have a little better specs, better reviews, and are also a fair bit more expensive.
I was fine with using the Canadian Solar panels, but I'm wondering why they made the change. They emailed me asking about the Canadian Solar panels after the plans with the Q.Cell panels had already been approved by the city, but before I got a copy. When I asked my contractor about it, he just said "We will correct it before inspection."
Is this okay? It smells a little funny to me to change to a cheaper panel type from what was approved in the permit, and I'm wondering if I'm going to have problems clearing inspection after they're done. I'm in the US.
Datasheet on the Canadian Solar panels: https://www.canadiansolar.com/upload/bc48dbe8c5c41fed/ab28643aabcece82.pdf
And on the Q.Cell panels: https://www.q-cells.com/dam/jcr:4fcbaac5-18ed-4e46-aa6c-fb53b5dbe957/Hanwha_Q_CELLS_Data_sheet_QPEAK_DUO-G5_315-330_2018-03_Rev03_NA.pdf
To my eye, the specs look pretty similar. The Q.Cells have a slightly better linear dropoff warranty and a few other pretty minor differences. The Canadian Solar panels are monocrystaline while the Q.Cells are two crystals. To my eye, in terms of what's on the datasheet, there isn't a lot of difference, but I am not expert enough to know if I'm missing anything major. The Q.Cells seem to have generally better reviews and are markedly more expensive, but I'm not sure why.
Best Answer
If you're using microinverters there are some circuit calculations you're supposed to do using the panel specs and local temperatures to let you know the maximum number of those panels that can be chained together.
If you got different panels then you paid for, I hope you got refunded appropriately! Besides initial specs, I believe mono panels age better than poly in terms of output degradation over time.