Solar Panels Tempered glass sub-strate is self cleaning, highly transmissive and impact resistant. Anodised aluminium frame is corrosion resistant and compatible with Solarex mounting structures. Rugged and weatherproof construction. Operating range between -40 C and 90 C. A 20 year Performance Warranty, guaranteeing that the solar module will continue to deliver a minimum of 80% of it's rated power for 20 years is given with all modules rated at 40w and above. Even the lower power Mega modules carry a 10 year performance warranty.