RETC: UVID problems in PV modules could ‘become a major reliability issue’

Facebook
Twitter
LinkedIn
Reddit
Email
RETC PV Module Index Report catalogued 14 testing sequences, with UVID among one of them. Image: RETC.

In this year’s ultraviolet-induced degradation (UVID) testing, engineering advisory and test services provider Renewable Energy Test Center (RETC), has noticed that 40% of modules tested have returned with a red flag result.

In its sixth annual PV Module Index Report, RETC – a member of the VDE Group – said that “without immediate and collective action, UVID has the potential to become a major reliability issue for industry stakeholders.”

This article requires Premium SubscriptionBasic (FREE) Subscription

Unlock unlimited access for 12 whole months of distinctive global analysis

Photovoltaics International is now included.

  • Regular insight and analysis of the industry’s biggest developments
  • In-depth interviews with the industry’s leading figures
  • Unlimited digital access to the PV Tech Power journal catalogue
  • Unlimited digital access to the Photovoltaics International journal catalogue
  • Access to more than 1,000 technical papers
  • Discounts on Solar Media’s portfolio of events, in-person and virtual

Or continue reading this article for free

As per RETC’s criteria, any maximum power degradation higher than or equal to 5% was deemed as a red-flag result, while some of the results have shown double-digit power loss in commercially-produced modules with a degradation ranging between 10-16% in the first three years of in-field operation. That double-digit power less would far exceed the allowable limits found in PV modules warranty terms and PV system power guarantees, according to the report.

In the 2022 edition of its report, the company had already noticed issues with UVID, more particularly in newer cell technologies, among which tunnel oxide passivated contact (TOPCon) solar cells. In that edition, the study indicated “cause for alarm”.

Despite the fact that 40% of the modules tested have shown a red flag, the same amount (40%) have met RETC’s UVID high achiever criteria. In order to reach that criteria modules had to withstand UV220 exposure with less than 2% degradation in maximum power.

Cherif Kedir, president and CEO of RETC, said: “Since the passage of the Inflation Reduction Act (IRA) in 2022, companies have announced nearly US$17 billion worth of investments in new and expanded solar manufacturing capacity additions in the US.

“Given the unprecedented market expansion in the world’s second-largest solar market, industry stakeholders must remain vigilant regarding technical risks inherent to supply chain diversification and the accelerated time frames between innovation and mass production.”

8% of modules tested achieved “Overall Highest Achiever”

The bankability tests conducted by RETC are catalogued in 14 testing sequences – including damp heat, UVID, hail durability test and thermal cycling, among others – and data according to three categories: module reliability, performance and quality.

Across these 14 testing categories, 23 module manufacturers have been recognised in some form of high achievement. Overall, 8% of modules tested have met RETC’s top accolade of “Overall Highest Achiever”. Whereas 14% of modules tested have shown some sort of red flag.

Read Next

June 27, 2025
Indian solar manufacturer Premier Energies has commissioned its 1.2GW TOPCon solar cell manufacturing line at Fab City, Hyderabad, Telangana.
June 18, 2025
The solar manufacturing and module purchasing community met in Napa to answer the question of 'what next?' for module supply in uncertain times.
Premium
June 17, 2025
Traditional PV inspection methods using direct current polarisation have proved unreliable in detecting certain issues. Researchers from Enertis Applus+ detail a new approach to defect detection aimed at improving the efficiency of PV system maintenance and performance analysis.
June 17, 2025
Indian module manufacturer Ahaan Solar has started construction of a 2GW solar module assembly plant in Rohnat, Haryana.
Premium
June 13, 2025
SNEC 2025 takeaways: TOPCon modules set benchmark power at 650W, a wave of BC modules and perovskite tandem cells gains momentum.
June 11, 2025
Lab-tested solar module performance has improved over the last year, according to data from US-based technical advisory firm RETC.

Subscribe to Newsletter

Upcoming Events

Upcoming Webinars
June 30, 2025
10am PST / 6pm BST
Solar Media Events
July 1, 2025
London, UK
Solar Media Events
July 1, 2025
London, UK
Media Partners, Solar Media Events
July 2, 2025
Bangkok, Thailand
Media Partners, Solar Media Events
September 2, 2025
Mexico City, Mexico