Monocrystalline Silicon Solar PV: most efficient
Generally, monocrystalline silicon solar PV is the best technology to deliver efficiency, as measured by wattage output related to the panel’s size. But this efficiency can come with costs. The best value is solar PV technology is polycrystalline silicon, offering efficiency levels close to monocrystalline panels, but at half the costs in some cases. Monocrystalline solar is made by growing a single crystal. Because these crystals are usually an oval shape, monocrystalline panels are cut into the distinctive patterns that give them their recognizable appearance: the sliced silicon cells expose the missing corners in the grid-like structure. The crystal framework in a monocrystalline is even, producing a steady blue color and no grain marks, giving it the best purity and highest efficiency levels.
Polycrystalline Silicon Solar PV: best value
Polycrystalline solar is made by pouring molten silicon into a cast. However, because of this construction method, the crystal structure will form imperfectly, creating boundaries where the crystal formation breaks. This gives the polycrystalline silicon its distinctive, grainy appearance, as the gemstone type pattern highlights the boundaries in the crystal. Because of these impurities in the crystal, polycrystalline silicon is less efficient when compared with monocrystalline. However, this manufacturing process uses less energy and materials, giving it a significant cost advantage over monocrystalline silicon. (Polycrystalline and multicrystalline are often synonyms, but multicrystalline is often meant to refer to silicon with crystallites larger than 1 mm.)
Thin-Film Solar PV: portable and light weight
The technology with the lowest market share is thin-film, but while it has several disadvantages, it is a good option for projects with lesser power requirements but needs for light weight and portability. Thin-film technologies have produced a maximum efficiency of 20.3%, with the most common material amorphous silicon at 12.5%. Thin-film panels can be constructed from a variety of materials, with the main options being amorphous silicon (a-Si), the most prevalent type, cadmium telluride (CdTe) and copper indium gallium selenide (CIS/CIGS). As a technology that’s still emerging, thin-film cells have the potential to be less expensive. Thin-film could be a driver in the consumer market, where price considerations could make it more competitive.