YingLI 230w Polycrystalline solar panel 1,Using high quality Motech solar cell. 2,Certificate: IEC,TUV, CE and RoHS YingLI 230w Polycrystalline solar panelMaterial: Multi ... more than 25 years Standard testing condition: 25, AM1.5 spectrum, 1,000W irradiance Insulation: >100M Ohms Voltage stand ... Any large or small on-grid or off- grid solar power station.2, Commercial and industrial building roof-top ...