100W ETFE Solar Panel: BigBlue solar panels combine high quality ETFE, UV-resistant EVA and efficient solar cells. ETFE (Ethylene Tetrafluoroethylene) is extremely durable and resistant to environmental elements, which is corrosion resistance, waterproof and fire retadancy. Double life-span compared to other PET solar panels and the light transmittance is up to 95%, you'll get the good quality and high efficiency together.