In the current market, there are two types of solar panels namely:
- Crystalline (polycrystalline & monocrystalline)
A thin-film solar cell is made by depositing layers of light-absorbing material (photovoltaic) material on a substrate – metal, plastic etc.
As the name suggests, the thinness of the cell is the characteristic that differentiates a thin-film solar panel from a crystalline silicon panel. Typically, its thickness ranges from a few nanometers to 1 micron.
Primarily, there are 3 kinds of thin-film cells in use today, namely:
- Amorphous silicon (a-Si)
- Cadmium Telluride (CdTe)
- Copper indium gallium arsenide (CIGS)
Why thin-film cells?
Traditional crystalline silicon utilized considerably large amounts of silicon and this increased their manufacturing costs. The idea of developing solar panels with considerable savings on raw material, thereby reducing the cost per watt, propelled the concept of thin-films forward.
Their contrasting features are tabulated in the following table:
As the table above suggests, low cost, flexibility and better performances at high temperatures are some of the key strengths thin film solar cells have over crystalline solar cells. However, their lower efficiency compared to that of crystalline solar panels also mean that they require a larger area for generating the same units of electricity.
Although thin-film cells cost less, they require more area for installing the panels. In the case of rooftop solar, area available for installation is a constraint. Therefore, as a general consensus, thin-film cells are not the best solar panel choice for rooftop solar due to their lower space efficiency.
Moreover, due to their low market penetration, there are not many solar installers who facilitate thin-film solar cell installations.