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 5, 2025
Solar manufacturer Involt Energy has broken ground on its first solar cell manufacturing plant in the western Indian state of Gujarat, with an initial annual nameplate capacity of 1.78GW. 
June 4, 2025
Chinese PV module manufacturer Haitai Solar has announced the termination of a 10GW TOPCon and the reallocation of investment to fund an Indonesian facility.
June 4, 2025
A total of 83% of module manufacturers have had at least one test failure in the Kiwa PVEL 2025 Module Reliability Scorecard, up from 66% a year ago.
June 2, 2025
The LECO process used in the production of TOPCon solar cells could increase their resistances by 'orders of magnitude', per new research.
Sponsored
May 28, 2025
Ben Willis speaks to Astronergy about its next-generation TOPCon offering and the advantages of its zero-busbar module design, both of which were on show at Intersolar 2025.
May 12, 2025
Researchers from the University of New South Wales (UNSW) and the University of Newcastle have found that “hidden contaminants” in TOPCon and HJT modules can lead to a power loss of up to 16%.

Subscribe to Newsletter

Upcoming Events

Solar Media Events
June 17, 2025
Napa, USA
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
Solar Media Events
September 16, 2025
Athens, Greece