698 GWp of solar photovoltaic capacity was added globally in 2025 — the largest single-year expansion of any electricity generation technology in recorded history. Cumulative installed capacity reached approximately 2,974 GW by the end of 2025, nearly triple the total installed before 2020. The IEA’s Global Energy Review 2026 confirmed that solar PV accounted for more than three-quarters of all new renewable capacity additions worldwide last year.
The manufacturing quality infrastructure has not scaled at the same rate.
In June 2025, Kiwa PVEL published the 11th edition of its PV Module Reliability Scorecard. The headline finding: 83% of module manufacturers and 59% of bills of materials tested had at least one test failure. This is up from 66% of manufacturers and 41% of BOMs in the 2024 Scorecard. The trend line across five scorecards shows the failure rate rising consistently, not fluctuating.
The solar industry is installing at aerospace speed. It is auditing at consumer electronics standards. That gap accrues over a 25-year performance guarantee horizon, not a 12-month warranty period.
1. What the Kiwa PVEL Data Actually Shows
The 2025 Scorecard failure data is specific enough to be actionable. The most common failure type was visual inspection major defects at 60% of all failures. Power degradation failures accounted for 21%. Module breakage during Mechanical Stress Sequence testing increased sharply — the BOM-level failure rate for MSS rose from just 7% in 2023 and 2024 to significantly higher levels in 2025. Forty percent of manufacturers experienced at least one MSS failure.
Junction box failures appear in every edition of the Scorecard. Kiwa PVEL has flagged junction box reliability in six consecutive annual reports. One third of manufacturers in 2025 had at least one junction box-related failure: 11% with covers falling off, 8% with loose cables or exposed wires, 8% with bypass diode failures.
The persistence of these failure modes across six annual reports is not a quality improvement story. It is a process control story. These are known, documented, repeatable failure modes that a mature process control system would have addressed. The fact that they continue at the same manufacturers across multiple years is evidence that corrective action processes are not producing sustained improvement.
I have spent 26 years working in aerospace and automotive quality, primarily in carbon fiber composite structures. The failure modes in the Kiwa PVEL Scorecard are not unfamiliar. What is unfamiliar is the industry’s tolerance for their persistence.
2. The Process Control Gap: Three Specific Areas
Lamination Process Control
Photovoltaic module lamination is a thermal bonding process with direct parallels to aerospace composite manufacturing. Deviations in temperature profile — ramp rate, dwell time, peak temperature — produce encapsulant cross-linking variations that are invisible at final visual inspection but measurable in long-term field performance.
In aerospace composite manufacturing, lamination process parameters are specified, validated against process capability studies, and monitored with continuous SPC. Cure cycle records are mandatory deliverables — not optional documentation. In solar manufacturing, lamination process monitoring varies significantly between manufacturers.
NREL has explicitly noted that IEC 61215 is designed to identify early failures in the first 5-10 years — it is insufficient for assessing long-term risk or establishing field performance degradation over a 25-year service life. The standard itself acknowledges its limitation.
Bill of Materials Traceability
In aerospace, every component traces to a raw material certificate. This traceability is the foundation of root cause analysis when a field failure occurs years after delivery. In solar manufacturing, cell-level traceability within a module is frequently incomplete. When a field failure occurs in year 15 of a 25-year performance guarantee, the ability to establish whether the failure is systematic depends on traceability records that may not exist.
Supplier Qualification Depth
In July 2025, the Chinese Ministry of Industry and Information Technology convened leading solar manufacturers — including LONGi, JA Solar, Trina, and Tongwei — explicitly urging them to end „disorderly low-price competition“ and improve product quality. The Chinese government identified product quality deterioration as a direct consequence of aggressive price competition in a market where module prices had fallen to approximately USD 0.10/Watt — a 45% reduction year-on-year. Quality is the first casualty of margin compression in a commodity market.
3. What Aerospace Audit Methodology Brings to Solar Manufacturing
Process FMEA at the component integration level. Systematic FMEA on lamination, stringing, and junction box assembly processes identifies failure modes that standard factory acceptance testing does not detect. The failure modes in the Kiwa PVEL Scorecard are exactly the failure modes that a well-executed process FMEA would capture and address.
Statistical Process Control on key process parameters. Cell efficiency, Voc, Isc, and encapsulant cure temperature are measurable in-process. The data exists at most manufacturing facilities. The systematic use of that data for process control with control limits and trend analysis is less consistently implemented.
Supplier qualification with process audit depth. Material qualification in solar manufacturing typically relies on type certification and incoming inspection. An aerospace-style supplier qualification adds process audit — examining the actual manufacturing process, the process parameter controls, and the change management practices of the cell, encapsulant, and junction box supplier.
3 Concrete Actions
1. If you are procuring solar modules for utility-scale deployment under 20+ year performance guarantees, request Kiwa PVEL PQP test data for the specific BOM you are procuring — not just the manufacturer’s Top Performer status. Top Performer status does not mean every BOM from that manufacturer performs equivalently.
2. For solar module manufacturers: commission a process FMEA on your lamination and junction box assembly processes using AIAG-VDA FMEA methodology. The failure modes appearing in six consecutive Kiwa PVEL Scorecards are your starting point.
3. For EPC contractors and asset owners: specify cell-level traceability and lamination process record retention as contractual requirements in your module procurement agreements. This requirement is absent from IEC 61215 — it will not be enforced unless you enforce it.
👉 Request a Technical Consultation → www.skqc.org
Sources
- IEA — Global Energy Review 2026: Technology Solar PV and Wind (May 2026)
- Kiwa PVEL — 2025 PV Module Reliability Scorecard, 11th Edition (June 2025)
- TaiYang News — Test Failures Surge in Kiwa PVEL’s 2025 Module Reliability Scorecard (June 2025)
- NREL — IEC 61215 Qualification Tests vs Outdoor Performance
- PV Magazine — Solar approaches 3 TW, but the industry faces new challenges (May 2026)
#SolarEnergy #PhotovoltaicQuality #RenewableEnergy #QualityManagement #ProcessControl #SupplierAudit #IEC61215 #SKQC