PVEL Scorecard 2026: Top Performers and Reliability Takeaways

The November 2026 update to the Kiwa PVEL Scorecard names 48 manufacturers as PVEL Top Performers for 2026, up from 43 in the May edition. It also reports a record failure rate in testing: 87% of participating manufacturers and 61% of tested bills of materials (BOMs) had at least one failure.

Published by the independent lab Kiwa PVEL, the PV Module Reliability Scorecard is a widely used source of solar panel reliability testing data for installers, EPCs, and module buyers. Its 12th edition arrived in two parts this year, with a first release in May 2026 and an expanded update in November.

Breakage and delamination drove most failures, even as power loss improved in several tests. For solar installers, the takeaway is to evaluate specific module models and materials, not just brand reputation. This guide covers what the PVEL Scorecard 2026 found and how to use it when choosing modules.

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Key Findings From the 2026 PVEL Scorecard

The 2026 PVEL Scorecard shows modules losing less power in most stress tests, while more of them fail testing than ever before. Breakage and delamination drive most of those failures.

Here are the headline numbers from the November 2026 update:

• 48 Top Performer manufacturers, including 17 first-time Top Performers.

• 311 model types (BOMs) listed as Top Performers across at least one test.

• 7 BOMs earned Top Performer status in all seven reliability tests, and only 1 of those also topped PAN performance.

• 87% of manufacturers and 61% of BOMs had at least one failure, up from 83% and 59% in the 2025 Scorecard.

• 60% of manufacturers had at least one module breakage failure, still the most common failure mode.

• 45% of manufacturers had at least one delamination failure, triple the previous year.

• Power loss fell in several tests, most notably PID and UVID, and PAN energy yields kept rising.

What the 87% Failure Rate Means

The 87% figure counts manufacturers in Kiwa PVEL's testing program that had at least one BOM fail at least one test. It is not a field failure rate, a warranty claim rate, or the share of defective panels on the market.

According to Kiwa PVEL's failure analysis, a failure can be a major visual defect, a wet leakage safety failure, a nonfunctioning bypass diode, or a retest a manufacturer requests after excessive power loss. Many of these issues mirror the common solar panel defects installers see in the field.

The numbers still matter. They show that a module's brand alone tells you little about whether the specific product you buy passed rigorous testing.

Keep two limits in mind when comparing years. The PQP covers products manufacturers choose to submit, not a representative sample of every module sold, and Kiwa PVEL changed its per-test failure rate calculation in 2026 to count only BOMs that underwent each test.

What Changed in the November 2026 Update?

The November update added five Top Performer manufacturers and, for the first time this year, BOMs that excelled across every reliability test. The record failure rate did not change.

This is the first year Kiwa PVEL has published the Scorecard twice. The May 2026 release covered testing completed by that point, and the November edition adds results from BOMs that finished testing since.

Measure	May 2026	November 2026
Top Performer manufacturers	43	48
First-time Top Performer manufacturers	13	17
BOMs that were Top Performers in all reliability tests	None	7
Manufacturers with at least one failure	87%	87%
BOMs with at least one failure	61%	61%

The all-star shift is the biggest change. In May, no single BOM qualified as a Top Performer across every test, a first in the Scorecard's history. By November, seven BOMs reached Top Performer status in all seven reliability tests.

UVID (ultraviolet-induced degradation) became a Top Performer category with the 2026 edition, so it appears in both releases. Kiwa PVEL hasn't committed to a fixed schedule beyond 2026, so check the Scorecard site for future updates.

2026 PVEL Top Performer List

The November 2026 Kiwa PVEL Scorecard names 48 Top Performer manufacturers, including Qcells, Trina Solar, Jinko, LONGi, and Canadian Solar. A manufacturer's listing doesn't mean every module it sells earned Top Performer status.

The table below groups all 48 by how many of the eight Top Performer tests they have at least one qualifying model in, based on the 2026 Top Performers by manufacturer page.

Tests With a Top Performer Model	Manufacturers
All 8 tests (7 manufacturers)	Adani Solar, Elite Solar, NE Solar, Qcells, Trina Solar, Waaree, ZNShine Solar
7 tests (16 manufacturers)	Aiko Solar, Canadian Solar, ES Foundry, Fellow Energy, HT-SAAE, Illuminate USA, Jinko, LONGi, Phono Solar, ReNew, RenewSys, SEG Solar, Thornova, Tongwei, Toyo Solar, VSUN
6 tests (12 manufacturers)	Astronergy, Atelier Solar, Avaada, DMEGC Solar, EMMVEE, Goldi Solar, Grew Solar, Hounen Solar, Pahal Solar, Premier Energies, Tide Solar, Yingli Solar
5 or fewer tests (13 manufacturers)	Bila Solar, Gautam Solar, GCL, Gokin Solar, Gstar Solar, JA Solar, Jolywood, Rayzon Solar, Solex, Sunpro Power, Tata Power Solar, TCL Solar, Vikram Solar

Why the BOM Matters More Than the Brand

Top Performer status belongs to a specific model type built from a specific bill of materials, not to a manufacturer's whole catalog. A different glass thickness, encapsulant, cell supplier, or factory creates a different BOM that may never have been tested.

A manufacturer in the "all 8 tests" row has at least one qualifying model in each test, which may be several different models. Only 7 individual BOMs topped all seven reliability tests. Look up the exact model in the Top Performer search tool before treating it as tested.

2026 Top Performers With US Factory Locations

Several 2026 Top Performer BOMs list at least one US factory location:

• Qcells: Dalton and Cartersville, Georgia

• ZNShine Solar and Hounen Solar: Orangeburg, South Carolina

• Bila Solar and ES Foundry: Indianapolis, Indiana

• Toyo Solar: Houston, Texas

Some of these manufacturers also list overseas factories. Factory location alone doesn't establish domestic content bonus eligibility or compliance with sourcing restrictions, so confirm the exact product and supporting documentation with suppliers.

Why Are PVEL Module Test Failures Increasing?

Module breakage and delamination account for most of the 2026 failures. Kiwa PVEL reports that major visual defects make up 73% of all failures, and breakage and delamination drive nearly all of those.

These problems tie back to industry-wide trends toward larger, thinner, lighter modules and changing materials. Here is what the lab found and what it means on a rooftop or ground mount.

Solar Panel Breakage Under Load and Hail

Sixty percent of manufacturers had at least one module break during testing. Breakage hit 26% of BOMs in the mechanical stress sequence (MSS) and 23% of BOMs in the hail stress sequence (HSS).

Kiwa PVEL lists the glass thickness and hail size for each HSS Top Performer, since thinner glass is more vulnerable to impact. For projects in hail-prone or heavy-snow regions, solar panel durability in extreme weather depends heavily on glass thickness, frame design, and the mounting method used in testing.

• Check whether the model passed MSS and HSS, not just one of them.

• Compare the tested mounting configuration with your racking layout.

• Confirm mechanical load ratings against site snow and wind loads.

Solar Panel Delamination

The share of manufacturers with a delamination failure tripled in one year, reaching 45%. About a third of those failures appeared after damp heat testing, but some showed up before stress testing even began.

Kiwa PVEL found bubbles and delamination along the perimeter of many glass/glass BOMs and linked the problem to encapsulant choices and lamination processes. Delamination can reduce electrical insulation, which turns a cosmetic issue into a safety concern.

Junction Box and Bypass Diode Failures

Junction box failures fell over the past year but still affected 21% of manufacturers. That includes 17% with at least one failed bypass diode and 9% with a safety failure traced to the junction box.

A bypass diode that fails open may no longer protect its cell substring during shading, which raises hot-spot risk. A diode that fails shorted can permanently bypass part of the module and reduce output. Kiwa PVEL also notes a rising number of field reports of junction box melting, including some linked to vegetation fires.

UVID and TOPCon Solar Panel Reliability

UVID results improved, but they remain a concern for n-type modules. According to Kiwa PVEL's UVID test page, median UVID power loss for TOPCon BOMs fell from 4.2% to 3.0%, and the share of BOMs with a UVID failure dropped from 6% to 3%.

The spread between modules is still wide. In one example, two BOMs using cells from the same supplier lost 14.1% and 3.6% of their power, a difference driven by the cell process recipe. As TOPCon becomes the default for many new solar panel technologies, UVID results are worth checking model by model.

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What Do PVEL's Reliability Tests Measure?

Kiwa PVEL's Product Qualification Program (PQP) runs extended stress tests that go beyond standard IEC and UL certification. The 2026 Scorecard has eight Top Performer categories: seven reliability tests plus PAN performance, which models energy yield. A module must clear a specific threshold in each one to earn Top Performer status there.

In every test, the module also can't have a wet leakage failure, a major visual defect, or a bypass diode failure. The Scorecard methodology lists these Top Performer criteria:

Test	What It Simulates	Top Performer Threshold
Thermal cycling (TC)	Repeated daily temperature swings that stress solder joints and interconnects	Less than 2% power loss
Damp heat (DH)	Long exposure to heat and humidity, as in hot, humid, or coastal climates	Less than 2% power loss
Mechanical stress sequence (MSS)	Snow and wind loads followed by temperature and humidity stress	Less than 2% power loss, with the tested mounting shown
Hail stress sequence (HSS)	Hail impacts followed by environmental stress	No glass breakage with 40 mm or larger hail
Potential-induced degradation (PID)	High system voltage combined with heat and humidity	Less than 2% power loss in both PID(+) and PID(-)
Ultraviolet-induced degradation (UVID)	UV exposure that degrades sensitive cells, especially TOPCon	Less than 2% power loss
LID + LETID	Light-induced and light- and elevated-temperature-induced degradation	Less than 1% combined power loss
PAN performance	Modeled energy yield using PVsyst PAN files	Top quartile for energy yield

PAN performance measures energy yield, not durability. For a ranking of modules by efficiency, see our guide to the most efficient solar panels.

The 2026 Scorecard reports that 93% of tested BOMs used rear glass instead of a backsheet, reflecting the shift toward glass/glass and bifacial solar panels. Kiwa PVEL's findings show that glass thickness, encapsulants, and lamination quality all influence breakage and delamination, so reliability varies widely among glass/glass designs.

How Installers Can Use the PVEL Scorecard for Module Procurement

Use the PVEL Scorecard as a screening tool, not a final verdict. Top Performer results show how a specific tested BOM handled accelerated stress, but they don't guarantee 25- or 30-year field performance.

Many manufacturers never submit modules for PQP testing, so a brand missing from the list isn't automatically unreliable. Its modules simply lack this independent data.

Module Procurement Checklist

Before you specify a module for upcoming projects, work through these checks:

• Match the exact model and BOM. Ask your distributor for the factory and BOM details, then compare them with the Scorecard listing. Some listed modules are variants, not independently tested BOMs, so ask the manufacturer how your configuration relates to the tested design.

• Prioritize the tests that match site risks. Focus on HSS in hail country, MSS for heavy snow and wind, DH and PID for hot, humid, or coastal sites, and UVID for TOPCon modules in high-sun regions.

• Ask about material substitutions. A new encapsulant, glass supplier, or cell source can change results, so ask how the manufacturer controls BOM changes.

• Request test reports. Manufacturers can share their PQP reports with buyers, and Kiwa PVEL publishes procurement best practices for module purchasing.

• Check the datasheet against the design. Confirm dimensions, weight, mechanical load ratings, and electrical specs for the racking and string design.

• Weigh warranty and support. Review warranty terms, US service presence, and replacement availability alongside test results.

When a Module Swap Affects Your Plan Set

Supply shortages and pricing shifts often push installers to substitute modules after a design is complete. A new module can change Voc and Isc, maximum string length under the system voltage limit, inverter or optimizer compatibility, clamp zones, and structural loads.

A substitution doesn't automatically require every calculation or plan sheet to change. The design team should compare the specs and decide whether revised documents or AHJ approval are needed, since many AHJs require revisions when installed equipment differs from the approved solar plan set.

What to Check Before Accepting a Substitute Module

Split the review into reliability questions and design questions. This table covers both:

Question	Why It Matters
Is this the tested model or a listed variant?	Similar model numbers can use different BOMs
Did it qualify in the stress tests that match site risks?	Hail, snow and wind loads, humidity, and UV exposure vary by site
Has the glass, cell, or encapsulant supplier changed?	Material substitutions can change reliability results
Does it work with the approved string design?	Voc, Vmp, Isc, Imp, and inverter limits need verification
Does it fit the approved layout and racking?	Dimensions, clamp zones, attachment details, and loads may change
Does it affect permit or interconnection approval?	Revisions may be needed before installation

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PVEL Scorecard 2026 FAQ

These answers cover common questions about the Kiwa PVEL Scorecard, Top Performer status, and past editions.

How Often Is the PVEL Scorecard Released?

Kiwa PVEL has historically published the Scorecard once a year. In 2026, it released the 12th edition in May and an expanded update in November, the first time it has published twice in one year.

Where Can I Download the PVEL Scorecard PDF?

Kiwa PVEL offers a free executive summary PDF of the 2026 Scorecard on its download page. The summary lists Top Performer manufacturers and key takeaways, while the full searchable results are on the Scorecard website.

What Does PVEL Top Performer Mean?

A PVEL Top Performer is a module model type, built from a specific tested BOM, that met Kiwa PVEL's threshold in a particular test. A manufacturer can be a Top Performer in one test and absent from another.

Is PVEL Top Performer the Same as Tier 1?

No. Tier 1 lists, such as the one from BloombergNEF, rank manufacturers by bankability and financing history, not by lab testing. PVEL Top Performer status reflects independent reliability and performance test results for specific modules.

Does a PVEL Test Failure Mean a Module Is Defective?

Not necessarily. PQP tests are more severe than standard certification, and a failure means a tested BOM had a major defect, safety issue, diode failure, or power loss retest during that testing. It doesn't measure field failure rates, but it flags risks worth asking the manufacturer about.

Are Solar Panels From Manufacturers Not Listed by PVEL Unreliable?

No. The Scorecard only includes manufacturers that submit modules to Kiwa PVEL's PQP and meet its listing criteria. To evaluate unlisted modules, review product certifications, independent test reports, warranty terms, and the manufacturer's quality controls.

Are the 2024 and 2025 PVEL Scorecards Still Available?

Yes. Kiwa PVEL keeps past editions online, including the 2025 Scorecard and the 2024 Scorecard. The 2025 edition reported failures at 83% of manufacturers and 59% of BOMs, compared with 87% and 61% in 2026.