NAPA, California., April 16, 2026 /PRNewswire/ — Kiwa PVEL, the independent laboratory for quality and reliability testing of solar photovoltaic (PV) modules, today announced a significant update to its photovoltaic (PV) module product qualification program (PQP). The revisions directly address some of the global solar industry’s most growing concerns, including increasing field failures related to spontaneous glass breakage, structural frame failures and increasingly severe hail events.
“Industry-wide, we continue to see an increase in spontaneous glass breakage cases in the field,” said Tristan Erion-Lorico, vice president of sales and marketing at Kiwa PVEL. “As manufacturers move toward larger modules and thinner materials, these sudden breakouts have made it clear that more rigorous and statistically significant testing is needed. Our updated PQP now uses higher sample sizes and test-to-failure methodologies to better assess module durability.
New test-to-failure methods improve information on module ruptures
A key feature of the updated PQP is the introduction of test-to-failure (TTF) protocols for static mechanical load (SML) and hail testing. The new SML-TTF complements existing PQP Mechanical Stress Sequences (MSS) by quantifying the dominant failure mode and maximum achievable load for each module design subjected to PQP testing. It also expands the quantity of test samples to five additional SML-TTF samples, in addition to the two MSS samples.
The Hail‑TTF protocol replaces the legacy Hail Stress Sequence (HSS) in the PQP. The updated hail test increases the sample size to five modules and focuses on impact locations in areas most prone to failure, such as edges, corners and junction box regions. Hail‑TTF significantly improves repeatability and comparability between glass manufacturers and suppliers, increasing hail diameters until failure occurs, providing buyers with more quantifiable breakage thresholds.
Kiwa PVEL has also updated its PQP sample production witness process to more systematically verify critical dimensions of frames and lenses in factories, further reducing uncertainty related to material and assembly variability.
Updated stabilization process
As N-type technologies become dominant in the PV market, testing laboratories face increased measurement uncertainty due to metastability mechanisms. The Kiwa PVEL team has spent the last several years quantifying these effects and identified three distinct forms of metastability that can distort post-test performance measures:
- Slow degradation of dark storage following moist heat testing
- Accelerated degradation of dark storage following UV exposure and field exposure
- Potentially recoverable PID bias degradation following voltage stress
To counter these effects, the updated PQP introduces final stabilization steps, including short doses of full-spectrum light absorption and UV light absorption, after UVID, field exposure, damp heat, and PID testing. These steps ensure that post-test flash measurements more accurately reflect the true behavior of the module in the field.
Other PQP updates
Several other improvements further strengthen the relevance of PQP for modern modules:
- LID sample size reduced from 17 to 10 modules, justified by consistent low LID values in recent years.
- Consideration of current-induced preconditioning before testing (in addition to exterior and interior light absorption) to speed up testing and improve planning flexibility.
- Streamlined UVID sequencing, eliminating intermediate UV60 characterization in favor of continuous 120 kWh/m2 exposure, with an option to expand up to 360 kWh/m2 for nomenclatures that have greater sensitivity to UVID.
- Energy classes updated according to IEC61853-3/4 methodology, leveraging our high-precision PAN and IAM test data.
“Regularly iterating on the PQP makes it the most relevant test plan for today’s module technologies and failure modes,” said Kevin Gibson, general manager of Kiwa PVEL. “These updates allow module manufacturers to better showcase product reliability and performance on their current offerings. The new PQP also ensures that solar buyers receive meaningful, statistically robust and actionable data.
For more information, please visit kiwa.com/pvel/pqpv12.
About Kiwa PVEL
Kiwa PVEL is the leading reliability and performance testing laboratory for downstream solar project developers, financiers and asset owners worldwide. Part of the larger Kiwa Group, Kiwa PVEL’s integrated solar supply chain services offer technical solutions to mitigate risks, optimize financing and improve the performance of solar and energy storage systems throughout the project lifecycle.
Since 2012, Kiwa PVEL’s Product Qualification Program (PQP) has been globally recognized for replacing assumptions about PV module performance with quantifiable measurements. The associated data and advisory services offered by Kiwa PVEL provide vital procurement information to a network of downstream solar buyers. Visit kiwa.com/pvel and kiwa.com/solar to learn more.
Contact:
Ashley Fallon
Marketing Manager
ashley.fallon@kiwa.com
SOURCE Kiwa PVEL
