Polycrystalline (sometimes also called multi-crystalline) solar panels are the most common because they are often the least expensive. They are the middle choice in the marketplace almost as good as single-cell monocrystalline silicon panels but generally with better efficiency than thin film solar panels.

Polycrystalline cells can be recognized by a visible grain, a “metal flake effect”. The solar cells are generally square in shape and may have a surface that looks somewhat like a mosaic. That’s because of all the different crystals that make up the module.