The photovoltaic (PV) solar cell was invented in 1954. In the spring of 1997, Siemens announced the extension of its module warranty expanding it from 10 to 25 years. Even today, the risks associated with module performance over long periods of time are not fully understood as 85% of over 300 GW of installed PV capacity has been in the field for less than five years.
There are well over one hundred PV module manufacturers globally active today utilizing a broad range of materials, manufacturing techniques and quality control practices. This results in a wide range of product quality and reliability. To properly address the risk of early failure of today’s products, it is helpful to have a clear understanding of common PV module failures seen in operating PV power plants. Developing an understanding of how modules age in the field will highlight technology risks and enable the implementation of an effective procurement quality assurance strategy.
DNV GL developed the Product Qualification Program to support the downstream solar community back in 2013. The objectives of the program are twofold:
- It provides PV equipment buyers and PV power plant investors with independent and consistent reliability and performance data to help implement effective supplier management process
- It provides module manufacturers focused on the reliability of their products the visibility they need to be successful in this competitive market.
The Product Qualification Program provides DNV GL’s downstream partners with third party performance data as well as reliability data. Data in the PV Module Reliability Scorecard [link to publication] is pulled from this Product Qualification Program. In the past two years DNV GL has executed 40 qualification programs across 30 manufacturers. Based on DNV GL’s experience at least 6% of commercial PV modules do not pass the IEC 61215 thermal cycling test. Independent PV module sampling is a critical step in testing and qualification and this is done for all modules tested in the DNV GL Module Reliability Scorecard.
By choosing products with higher robustness, the likelihood of technical and financial success for a PV project is increased. Many module vendors performed well across all tests, where manufacturers degraded less than 3% after four times the IEC 61215 required duration in thermal cycling. The scorecard demonstrates that manufacturing location and size is not good proxies for module robustness.