PPG Industries' flat glass business announces that it can now manufacture heat-strengthened glass in thicknesses of less than 3 millimeters, making it among the first major glass manufacturers in North America to offer this capability.
PPG can produce heat-strengthened glass in thicknesses of 2, 2.5 and 2.7 millimeters with surface compression strength that exceeds that of fully tempered glass (greater than 10,000 pounds per square inch), while achieving ASTM C1048 standards for flatness. The added strength gives thin glass used in various solar applications that require resistance to wind load, hail impact and other environmental hazards the ability to meet UL and IEC (International Electrotechnical Commission) standards as well, which may help solar-module and solar-mirror manufacturers in North America.
When incorporated into solar modules, heat-strengthened thin glass permits more sunlight to reach the active layer, which enhances the conversion of sunlight into energy and increases power output. With 2-millimeter SOLARPHIRE(R) glass, solar transmittance improves by 0.3 percent compared to 3.2-millimeter glass and by 0.5 percent compared to 4-millimeter glass.
Heat-strengthened thin glass also gives solar manufacturers the opportunity to cut downstream costs. For instance, manufacturers may reduce material costs for solar modules by using glass-on-glass module designs that eliminate the need for - and expense associated with - traditional protective plastic or polyvinyl fluoride (PVF) backing.
When used in solar mirrors for concentrated solar power (CSP) and concentrating photovoltaic (CPV) applications, heat-strengthened thin glass enables manufacturers to cold-bend reflective (mirror) glass into shorter-radius support frames with less chance of stress breakage. This can be less expensive and simpler than doing so with thick glass that is thermally bent before mounting. Cold-bending thin glass can reduce freight costs when mirrors are shipped flat directly to field sites for installation. Thin glass also significantly increases the reflectivity and related energy output of solar mirrors.