Single crystal, Multicrystalline, Amorphous silicon of solar
The most common solar cell types used in solar panels are the silicon forms.
Single crystal silicon is the most expensive, but is also the most efficient, so less area is needed.
Single crystal cells work better in hot weather and low light conditions than multicrystalline (poly-crystalline) or amorphous cells. Because they can sometimes be smaller for the same wattage, they can reduce the wind and gravity load on systems that track the sun (as opposed to systems that are fixed in one position).
Multicrystalline (poly-crystalline) panels, while having lower efficiencies than single crystal panels, can nonetheless have the same wattage per square foot as some single crystal panels, because the cells can be rectangular, filling all of the available surface without the gaps left by round or octagonal cells used in some single crystal panels.
Amorphous silicon (a-Si) is the non-crystalline form of silicon. One of the main advantages of amorphous silicon over crystalline silicon is that it is much more uniform over large areas.
