Technologies of Modules

There are three different kinds of solar modules which are available commercially. Namely:

 

Amorphous silicon modules
The silicon material is vaporised and sprayed onto a glass or steel substrate. This costs less than the other technologies of panels, but is also the least efficient of all 3. Present day technology does claim to have improved the efficiency of this module. These cells are dark brown to almost black in colour.  

 

 

Mono-crystalline modules
This is the oldest and most expensive technique, but is still the most efficient sunlight conversion technology available. Large cylindrical loaves of pure single-crystal silicon are grown in an oven, then sliced into wafers and assembled to look like the picture below.

 

 

Poly-crystalline modules
In this technique, less "loafs" are grown and then sliced into wafers off a large block of polycrystalline  silicon. It is slightly lower in conversion efficiency than mono-crystalline modules, but the manufacturing costs are also lower. Crystals can be seen in the module and have a deep blue colour.