UL (Underwriters Laboratories) has launched a new global service, offering a PV Power Plant Certificate to verify the performance of PV systems at several key stages, such as commissioning or during operation. The delivered certificate is also made publicly available in UL’s online database, providing greater transparency for all stake holders.

■ Problem

Grid connected PV systems are expected to have a lifetime of several decades, with maintenance or modifications likely at some point over this period. The ownership of a system may also change over time, particularly for megawatt-scale ground-mounted PV power plants and systems mounted on commercial buildings. Only adequate documentation, operations and maintenance procedures can help ensure the long-term performance and safety of the PV plant.

■ Solution

UL’s verification and inspection service issues a UL inspection report and UL inspection certificate by assess PV power plant projects during their commissioning and/or their operation against a set of criteria to demonstrate that the systems are performing at a level based on the IEC 62446-1 Standard and verified by an independent third party. The delivered certificate attests that a PV power plant complies with the criteria outlined in the inspection program at the time of the inspection and will be made publicly available in UL’s online database.

■ Applications

UL’s verification and inspection service issues a UL inspection report and UL inspection certificate for solar PV power plants ranging from small commercial and industrial to large megawatt-scale projects.

■ Platform

Based on requirements, UL offers a tiered approach for field inspections based on IEC 62446-1 to offer clients the best certification solution to meet their needs. This could be driven by local regulations, consultants, banks or investor requirements, or by costs. The UL inspection certificate is available at two tiers: ‘Standard’ or ‘Performance’ and generally includes a desktop review of the power plant’s components; a visual field inspection of the power plant which is compliant with ISO 17020; and testing of some of the power plant’s components. All category #2 tests in accordance with IEC 62446-1 include; current-voltage curve (IV-curves) measurement of selected strings and thermographic inspection (IR imaging), undertaken while walking/driving/flying through/over the PV power plant.

■ Availability

July 2018, onwards.