There are several key statistics that need to be kept in mind when discussing the windshield production process. First, auto glass manufacturing is a very high-temperature process, which also means that it is a very energy intensive process. The World Bank Group (Environmental, Health, and Safety Guidelines for Glass Manufacturing) reported that it results in high levels of sulfur dioxide, carbon dioxide, nitrogen oxides. Additionally, the high temperatures lead to oxidation of the surrounding atmospheric nitrogen.
Windshields are two-ply glass and lamination, which means that they have two layers of glass. It has been reported that, on average, it takes 15.2 million BTU’s of energy to create 1 ton of glass. The Rhode Island Resource Recovery Corporation reported that this leads to 285 pounds of mining waste as well as 28 pounds of air pollutants. While it is impossible to eliminate the waste resulting from this process, by decreasing the needs for new windshields, this process can be minimized, which is exactly what repair does.
The second impact area that rock chip repair is beneficial is the disposal of broken windshields. The California Department of Conservation estimates that glass can take more than 1 million years to completely decompose within a landfill setting. Additionally, recycling windshields simply isn’t an option because it is a laminated two-ply with a PVB layer that must be separated. British Glass (Glass Manufacture: A Mass Balance Study) stated that integrated heating elements and radio antenna are often embedded within the windshields which means that they cannot be returned to a glass furnace for recycling.
The Boston Globe estimated that more than 11 million windshields are replaced every year. With an average weight of about 25 pounds, this quickly adds up to more than 275 million pounds of waste every year. By opting for windshield repair over auto glass replacement, these affects can be greatly reduced. While it is impossible to repair every windshield, there are a large number of windshields that could easily be fixed instead of being discarded. While windshield repair is not a total solution to eliminate the environmental impact of windshield production and disposal, it can go a long way to minimizing it.