Overview

Polycrystalline panels, sometimes referred to as multicrystalline panels, are popular among homeowners looking to install solar panels on a budget.
Usually, polycrystalline silicon solar cells won’t have the corners cut off of them, so you won’t see the large white spaces on the front of the panel that you see on monocrystalline panels.
The way they are manufactured causes the panels to have a blue color, which some people consider to be an eyesore. The manufacturing process also makes them less efficient than monocrystalline panels.

Construction

Polycrystalline solar cells are manufactured like monocrystalline panels - a seed crystal is placed into molten silica. However, instead of pulling out the silicon seed crystal, the whole vat of silicon cools. This cooling process causes multiple crystals to form.
The multiple crystals are what cause the panels to have that ‘marbled’ blue appearance. Just like monocrystalline panels, polycrystalline panels will contain either 60 or 72 cells.

Performance

The multiple silicon crystals in each solar cell makes it harder for electrons to flow. This crystal structure makes the efficiency rate of polycrystalline panels lower than monocrystalline panels. Polycrystalline panel efficiency ratings will typically range from 15% to 17%.
However, thanks to new technologies, polycrystalline panels are now much closer in efficiency to monocrystalline solar panels than they have been in the past.
Quality improvements have also helped push the standard 60-cell polycrystalline panels from 240 watts to over 300 watts.

Cost

Polycrystalline solar panels are cheaper to produce than monocrystalline panels, which allowed them to make up a significant market share in residential installations between 2012 and 2016.
But while they’re still cheaper than monocrystalline panels, it’s not by very much. This, plus their lower performance has caused more people to choose monocrystalline solar panels over time.