NREL calls for international quality standards in PV module manufacturing

The U.S. Energy Department’s National Renewable Energy Laboratory (NREL) has released a proposal to establish an international quality standard for PV module manufacturing.

The technical report, Updated Proposal for a Guide for Quality Management Systems for PV Manufacturing: Supplemental Requirements to ISO 9001-2008, is intended for immediate use by PV manufacturers when producing modules on an industrial scale so they can increase investor, utility and consumer confidence in PV system performance, according to NREL.

"Our recent research on 50,000 systems found that, during the time period we studied, just 0.1% of all PV systems were affected by damaged or underperforming modules and less than 1% experienced hardware problems each year," said Sarah Kurtz, one of eight authors of the technical report and a research fellow at NREL who manages the PV Reliability and Systems Engineering Group. "Even so, with manufacturers feeling pressure to lower prices, it is essential that quality be maintained and assured.”

The new guidelines will help ensure that quality is not compromised for lower priced modules and make it easier for PV customers to assess the expected quality, Kurtz added.

NREL worked with industry partners in the United States, including SunPower and First Solar, and international companies in Japan, Europe and China to develop PV-specific quality management standards to supplement the existing ISO-9001 in the application of International Electrotechnical Commission (IEC) standard 61215.

The document provides PV manufacturers the opportunity to begin to use the specification proposed for release in Technical Specification IEC/TS 62941, "Guideline for Increased Confidence in PV Module Design Qualification and Type Approval," which is to be finalized in late 2015. The new guideline describes aspects of the quality management system that needs to be in place when producing modules on an industrial scale.

With PV customers worldwide now investing in PV to the tune of some $100 billion annually, the international solar community is driven to maintain the quality of that investment, NREL points out. To that end, NREL, along with other international groups, has spearheaded the International PV Module Quality Assurance Task Force (PVQAT) to establish guidelines dealing with:

  • How to test PV modules for adequate durability for the chosen climate zone and mounting configuration
  • How to ensure consistent manufacturing of the durable design
  • How to ensure that the final system is fully functional

The PVQAT effort is closely coordinated with the IEC, which uses an international consensus process to refine and define the final documents. PVQAT’s Task Group 1 developed the first draft of the proposed PV manufacturing specification, which was published in 2013. The newly released technical report represents an update to the previous version, and includes progress made between 2013 and early 2015. Key requirements for manufacturers in the new specification include:

  • Focus on the manufacturer’s control of the PV module’s design to align the expected lifetime with its relationship to the manufacturer’s warranty.
  • A requirement to improve product traceability through the entire supply chain to enact positive control of the product for recalls and warranty claims.
  • A requirement to maintain calibration of the instruments needed to assign the PV module power rating within the stated uncertainty.

NREL said it encouraged the PV sector to use this approach to verify the robustness of their and their vendors’ quality management systems and to provide feedback to PVQAT and to IEC before the international standards process was completed.

The NREL-backed Solar Access to Public Capital (SAPC) working group recently released new best practices guidelines for solar PV systems with the goal of increasing investor confidence in the long-term viability of PV systems.