Solar Panel Glass
Solar Glass is one of the crucial barriers of traditional solar panels protecting solar cells against harmful external factors, such as water, vapor and dirt.
What properties are expected from solar glass?
High solar radiance transmittance
The type of solar glass directly influences the amount of solar radiation that is being transmitted. To ensure high solar energy transmittance, glass with low iron oxide is typically used in solar panel manufacturing.
Solar panels are made of tempered glass, which is sometimes called toughened glass. There are specific properties that make tempered glass suitable for the manufacturing of solar panels. First of all tempered glass is much stronger than other types of glass. Secondly, tempered glass is considered safety glass. In case it breaks, it will shatter in thousands of small pieces, that won't be harmful. Both the strength and safety is important for the installation of solar panels.
Solar glass, as the front sheet of a pv module, needs to provide long term protection against the elements. Glass is used because it's well known for its durability, even though it has disadvantages as well.
Anti-reflective (AR) Coatings
An anti-reflective (AR) coating can be added to solar glass by plating one layer of anti-reflection film before the glass is tempered. The coating will improve transmittance by reducing the reflectance on the surface of the glass.
The application of an AR coating on the glass surface can increase the share of sun irradiance effectively used for power generation by over 2.5%.
An alternative to an AR coating is Light-Trapping. A solar panel with this particular surface catches more solar radiation, mainly because not only direct sunlight reaches the solar cells, but also the less favorable, flat angle radiation is absorbed.