RETC PV Module Index highlights panel reliability concerns
VDE Group affiliate RETC has released its 2026 PV Module Index (PVMI) at a crucial time for the industry, as manufacturers around the world continue to face financial pressures and increasing demands.
The U.S. Energy Information Administration says it expects more than 43 GW of utility-scale solar to come online in the U.S. in 2026 alone. Thanks to the rise in AI data centers and utility electrification, the demand for large-scale solar is growing faster than ever in the U.S. The new PVMI report has found “signs of increasing reliability challenges” for PV modules, which could cause hiccups down the line for such massive projects.
Specifically, the PVMI notes that more than 10% of PV module samples returned failing results in “red-flag” tests in the 2,000 house damp heat test category. Additionally, RETC’s testing and reporting also identified modules with “unacceptable” levels of degradation when put under high levels of ultraviolet light.
“Certifications require products to meet a minimum baseline standard; however, they do not necessarily address how assets will perform throughout their projected lifetime in the field, specifically in recent years, under increasingly extreme conditions,” says Cherif Kedir, CEO of RETC. “In 2026, solar is now both critical infrastructure and a commoditized product, which makes quality differentiation paramount for long-term reliability, consistency, and performance.
“Stakeholders require more confidence that the products being deployed today will continue performing reliably over decades, especially as new manufacturing scales rapidly and new materials and supply chains hastily enter the market.”
The findings, and their deeper meanings for the solar manufacturing industry, are indicative of a wider change in thinking across the sector, RETC says.
An industrial paradigm shift
The 2026 PVMI’s testing was conducted between Q2 of 2025 and Q1 of 2026, and evaluated PV modules using RETC’s testing protocols. Designed to identify reliability and performance risks, the testing report shed light on emerging trends that now shape solar procurement, manufacturing, and perhaps most crucially, risk management.
In total, 19 manufacturers in RETC’s customer portfolio earned recognition in the 2026 PVMI for any number of testing disciplines and award categories. Among those 19, 13 manufacturers — including big names like Jinko Solar and LONGi — achieved “Overall Highest Achiever” status. Many of those higher achievers, according to Kedir, have chosen to focus on long-term risk assessment in their manufacturing as a top priority.
“What we are seeing is an industry moving from a deployment story to a performance and risk management story,” says Kedir. “The PVMI gives developers, financiers, and asset owners a clearer view of which modules perform under extended stress conditions designed to reflect the realities they will face in the field.”
Newly identified reliability and performance trends in the PVMI state that companies are shifting to trying to better understand their products. The industry is moving away from trying to constantly scale up deployment, and moving toward understanding how their assets will perform in 25, sometimes even 35 years. Any performance deviations, the testers say, could affect long-term project economics, as well as asset values.
“Underperformance in operational solar assets often results from the accumulation of many small losses, some of which are difficult to isolate due to measurement uncertainty,” the downloadable report says. “The exception to this general rule is availability, as these losses are often episodic but potentially severe. This is especially true in utility-scale PV power systems, where the loss of a single central inverter can significantly reduce instantaneous power generation capacity and daily energy harvest.”
Top findings
Increased manufacturer and solar asset operator anxiety over severe weather has become a paramount concern in the industry, with special attention being paid to hail risks. The PVMI says that though far less frequent than rain or snow, these events count for massive losses in the U.S. solar space.
“These infrequent yet costly tail risk events underscore the growing importance of beyond-certification hail testing, particularly as solar deployments expand across high risk regions such as Texas and other markets east of the Rocky Mountains,” the company says. “Ensuring that PV modules can withstand severe weather exposure over a 25- to 30-year project life now requires more rigorous approaches to durability characterization than conventional qualification standards alone provide.”
Perhaps the other big finding in the report is the rise of light induced degradation (LID).
As previously stated, high levels of ultraviolet light can slowly degrade the efficiency of solar panels over time. Companies are taking notice of this, Kedir says, and while susceptibility varies greatly, bringing down LID levels has become a concern for manufacturers.
“Gallium-doped p-type silicon technologies generally exhibit low LID risk, whereas boron-doped p-type PV cells are more vulnerable to boron-oxygen light-induced degradation (B-O LID),” the report says. “Manufacturers can mitigate B-O LID in boron-doped p-PERC technologies using advanced hydrogenation processes, though these approaches may increase susceptibility to LETID. As a result, module designers must carefully balance B-O LID mitigation strategies against potential LETID risk exposure.”
The 2026 PVMI is available for download now.
