... certification 3.High quality and best price 4.on time solar panel:Cell Typepolycrystalline SiliconCell Size(mm)156*156No.of Cell & Connections36Dimension ... use .the panel effciency is 90%,and 80% effciency after 20 year's use *certificates:TUV,IEC,CEC,CE,ISO Polycrystalline solar panel