Solar Energy Glass

Flat glass is an integral component of many solar energy technologies, including solar thermal collectors, photo voltaic modules and concentrated solar power plants. The solar energy market for flat glass is one of high added-value glass products and a strong driver for innovation. However, despite Europe's technological lead, a crumbling European market and unfair trade practices in the entire value chain have severely hit Europe's production. 
Glass is designed to optimise solar energy conversion while providing long term protection against external conditions. Extra clear glass, with low iron oxide content is typically used in solar applications. Either float or patterned, low iron glass may be coated with an anti-reflecting coating to further increase performance. Transparent conductive coating can also be used as an electrical contact in some photo voltaic technologies allowing the light through to the photovoltaic material while conducting the general electricity out of the modules. Glass may also be toughened to increase strength and durability.
Glass in solar thermal applications
Solar thermal collectors are intended to collect heat - as opposed to photo voltaic panels which convert sunlight into electrical power. The collected solar heat can be used to supply hot water or heat ex changers, for domestic or industrial applications.
There are various kinds of solar thermal collectors but most require a flat glass cover, or glazing, which serves not only to protect the panel while letting the sunlight through but also to prevent cooling of the panel from exposure to cold air.
Glass in photovoltaic applications
Photo voltaic technologies are used to convert solar energy directly into electricity. There are many different technologies available to suit various requirements, from domestic systems to utility scale. Photo voltaic panels come in various shapes and colors offering flexibility for design integration and building integrated applications (BIPV).
The most common photo voltaic technology is based on crystalline silicon solar cells. In this application glass acts as a protective outer layer, while transmitting the solar light to the photo voltaic cells interconnected underneath.
Other photo voltaic technologies include thin film where solar cells are deposited as a sequence of thin films on glass. In these technologies, transparent conductive coated glass can be used as the front glass upon which the films are grown. The conductive coating not only allows light through to the photo active films, but also conducts the generated electricity out of the modules.
Glass and mirrors in concentrated solar power Systems
Concentrated Solar Power (CSP) systems are used to produce electricity from the sun at utility scale. These systems are mainly used in regions with high levels of solar irradiance. CSP systems use lenses or mirrors to concentrate a large amount of sunlight onto a central receiver, thereby producing electricity either by concentrating the sunlight onto a high performance photo voltaic cell or by heating a transfer fluid to supply heat to a conventional thermodynamic power plant. For CSP systems, extra clear glass and mirrored glass are used to redirect accurately the maximum amounts of light towards the focal point.