Projecta 120W Solar Panel Polycrystalline Polycrystalline solar panels are manufactured from a solar cell that is cast from silicon. These cells are more efficient at producing power than an amorphous panel, so the size of the panel is smaller yet produces greater output power. Corrosion resistant frames are constructed to withstand wind speeds in excess of 130 km/h in typical ground mounted applications. The frames are clear anodized and the inner corner connection has a strong mechanical resistance to weather. Clear encapsulated insulation enhances solar cell performance and provides proven weather protection, Tempered low iron glass provides both better impact resistance and better light transmission, allowing the generation of more electricity by reducing the quantity of light that is reflected away from the module.