11% of Solar Panels Fail Critical Tests — Why This Matters for Your 2026 Purchase

A bombshell report released last week has revealed troubling quality issues with solar panels that could affect Australian homeowners considering a solar investment in 2026.

RETC, part of the VDE Group, has released its 2026 PV Module Index (PVMI) Report, showing that more than 10% of module test samples returned failing “red-flag” results in the 2,000-hour damp heat test category. The report tested panels between Q2 2025 and Q1 2026, making this the most current reliability data available.

What the Failures Mean for Australian Solar Buyers

Damp heat testing of solar PV modules yielded 11% “red flag results”, results that “raise concerns about a product’s ability to deliver reliable long-term performance”, according to this year’s PV Module Index (PVMI) Report, published by US-based technical advisory firm the Renewable Energy Test Centre (RETC).

The testing simulates Australia’s harsh climate conditions — particularly relevant given our extreme heat and humidity in northern regions like Queensland and the Northern Territory.

For the second consecutive year, approximately 8.3% of module test samples exhibited unacceptable levels of ultraviolet-induced degradation. With Australia receiving some of the world’s highest UV radiation levels, this finding is particularly concerning for local installations.

“In 2026, solar is now both critical infrastructure and a commoditized product, which makes quality differentiation paramount for long-term reliability, consistency and performance” — Cherif Kedir, CEO of RETC

The Performance Decline Trend

Between 2020 and 2024 the median score of modules tested, across all testing types, fell from 1.02 to 0.986; similarly, the average score of modules on a P90 basis fell from 0.96 to 0.85 over this period. This suggests solar panel quality has been declining even as efficiency improves.

RETC observed year-over-year increases in red-flag results across damp heat, potential-induced degradation, static and dynamic mechanical load, and thermal cycling test categories.

What Australian Homeowners Should Do

Focus on Proven Brands: RETC awarded a total of 13 companies its “overall highest achiever” status—Imperial Star, JA Solar, JinkoSolar, LONGi, Qcells, Runergy, Solarspace, Thornova, TrinaSolar, TW Solar, VSUN, Waaree and Yingli Solar. Nine of these companies have also received this award for at least three consecutive years.

Ask About Testing: When getting solar quotes, ask installers which brands they use and whether those brands achieved high ratings in independent testing programs like RETC’s PVMI or Kiwa PVEL’s reports.

Warranty Scrutiny: “Design optimisation efforts”, which aim to reduce the cost of manufacturing solar panels amid the ongoing price crisis affecting many Chinese manufacturers, could contribute to the decline in module performance, according to industry experts. This makes robust warranties more critical than ever.

The Broader Industry Impact

“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,” said Cherif Kedir, CEO of RETC. “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.”

For Australian households looking to install solar in 2026, this report underscores the importance of choosing quality over price. With solar systems expected to last 25-30 years, the upfront savings from cheaper panels could be wiped out by premature failures and reduced performance.

The timing is particularly relevant as many Australians are considering solar upgrades or first-time installations to combat rising electricity costs. Are Australian Solar Panel Prices Rising in 2026? What Homeowners Need to Know About Costs and Rebate Changes provides essential context on pricing trends, while homeowners should also consider Should You Upgrade Your Australian Solar System in 2026? Costs, Benefits & Up To $4,800 Rebates for upgrade decisions.

The RETC report serves as a crucial reminder that in Australia’s challenging climate, solar panel quality isn’t just about efficiency — it’s about durability that protects your investment for decades.