Sapa solar PV cells: a wide array of choices that can be combined and connected to suit every possible project requirement.
Polycrystalline cells are produced by pouring hot, liquid silicon into square molds or casts. The silicon is cooled to form solid blocks, which are sliced like single-crystalline silicon. The obtained mass is cut into rectangular rods which are sliced into thin wafers, forming a 'patchwork quilt' of single-crystalline silicon molecules. Since this technology is the best known and relatively cost-effective, polycrystalline cells remain the most commonly used.
Monocrystalline cells are created in a similar process as mentioned above but the ingots are manufactured according to the very complicated Czochralski process. The ingots have the same, strictly desired crystal orientation through their whole length. The shape of the cross section of an ingot is circular. Since it is a waste of surface to use round cells beside each other, a rectangular like shape is cut out of the ingots's cross section. The corners are left round because it would be too expensive to throw out the obsolete material after cutting out a full square from the inside of a circle cross section.
Thin-film technology cells
Thin-film technology cells are printed on glass in many thin layers, thus forming the desired modules. Manufacturing them requires less material than producing crystalline cells because no cutting is needed. In addition they only require laminating on one side since they are “glued” to a glass pane on the other side during the production process.
PV cell types and their efficiency
|16%||120||1.46 - 3.85|
|Monocrystalline – high efficient|
|125x125||22%||155||2.90 - 3.11|
|Monocrystalline - semitransparent|
|125x125||17%||105||1.90 - 3.11|
|aSi (amorphous Silicone) thin film|
|aSi thin film 10% or 20% opacity|
Possible combinations cell-type and cell distances