Glass substrates and cover plates form an integral part in harvesting solar energy. Since the cell efficiencies and performance of a solar harvesting device are directly related to the number of absorbed protons, the first and foremost demand for glass to be used in solar application is to have a very high transmission in the visible region of the electromagnetic spectrum. This makes the glass composition a very critical parameter as various additives to normal (clear) glass, which act as absorbing centres for photons in the visible region, need to be taken out of the glass compositions. In addition, one of the biggest requirements for solar glass is its chemical durability. Most of the harvesting devices/techniques involve exposing the device, and thus the glass, to outdoor environments. The glass needs to be durable to withstand sudden and drastic changes in temperature and humidity among other things, for prolonged and effective use. Furthermore, the glass needs to be mechanically strong as it is exposed to harsh weather conditions, which include rain, snow, sleet, hail etc. This paper takes a look at the various issues facing the glass selection in various solar related applications and will discuss the importance of glass composition in addressing these issues.
