I. Inspection
What to look for during inspection.
Based on inspection practices, the process covers the following: Continuity—(Continuity testing of PV modules is a critical electrical safety check; it involves verifying circuit connectivity—including cell interconnect ribbons, busbar connections, and internal junction box circuitry—as open circuits, cold solder joints, or poor contact can lead to reduced output power, localized overheating, and the “hot spot” effect); Appearance—(Group Standard T/JSREA 18—2024 “Quality Inspection Procedures for Key Equipment in PV Power Plants”; checking for neat and standardized cable routing and secure cable fixing; ensuring conduit entry/exit points are properly sealed); Mounting/Fixing—(Group Standard; checking for obstructions such as trees, power lines, or buildings; verifying the structural integrity and security of module-to-rack and rack-to-ground connections; checking for anti-rust coatings or plating on mounting structures); Nameplate—(Nameplate ratings, serial numbers, and traceability; visual inspection for glass cracks or frame deformation); Cables—(Group Standard; verifying the use of weather-resistant, UV-resistant, flame-retardant, double-insulated flexible copper cables; checking for proper terminal connectors; ensuring connections are tight and secure; verifying that cable gauge is sufficient for the maximum current load); EL (Electroluminescence)—(Qinghai Administration for Market Regulation; “Technical Specifications for On-site Detection of Hidden Defects in Crystalline Silicon PV Modules”; setting up a darkroom environment; capturing and archiving EL images of modules)—The inspection focuses on six key areas: continuity, appearance, mounting, nameplate, cables, and EL testing, ensuring a comprehensive assessment.
II.
Testing
What to look for during testing.
Based on testing practices, the evaluation covers six key areas: Dielectric Strength—Qingxi Technology (junction box terminal withstand test: 1500V AC for 1 minute with no breakdown; Beijing Qingxi Technology Research Institute); Contact Resistance—Qingxi Technology (four-wire measurement method requiring ≤5mΩ; insulation resistance ≥1000MΩ at 500V DC; Beijing Qingxi Technology Research Institute); High/Low Temperature—Xundao Testing (cycling between 85°C and -40°C to verify thermal expansion compatibility and fastener integrity; Xundao Testing); Salt Spray—Xundao Testing (corrosion test simulating coastal or saline-alkali environments to evaluate the corrosion resistance of terminals and conductors; Xundao Testing); Hipot—Suntree (high-potential testing at 3000V DC for 1 minute with no breakdown; contact resistance measured at 10A; Suntree); Water Immersion—Suntree (IP68 immersion at 1 meter for 30 minutes followed by electrical testing; 1000-hour accelerated UV aging at 60 W/m²; thermal cycling from -40°C to +85°C; Suntree)—comprehensive testing across these six parameters ensures thorough validation.
III.
Certification
What to look for in certification.
Regarding certification practices, consider the following six aspects: Scope—State Administration for Market Regulation (SAMR) (Implementation Opinions by SAMR, CNCA, and the National Energy Administration on strengthening PV product testing and certification; current scope includes PV modules, inverters, control equipment, combiner boxes, energy storage equipment, and standalone PV systems); Institutions—SAMR (Certification bodies conducting PV product certification must be approved by CNCA; testing and certification laboratories must obtain qualification accreditation in accordance with the law); IEC 61215—Fraunhofer ISE (PV module test lab established in 2006; over 50 test methods; includes all module tests from IEC 61215 and IEC 61730 standards); CQC—CQC (Rules for Comprehensive Quality Grade Certification of PV Modules CQC53-471547-2020; based on all test items regarding quality attributes in CQC5306-2020); “Top Runner” Program—CQC (General Rules for “Top Runner” Certification of PV Power Generation Products CQC33-407660-2017; backsheet material durability: Level 1—4,000 hours, Level 2—3,000 hours, Level 3—2,000 hours); Mandatory Standards—CAS Test (PV module testing based on IEC 61215, GB/T 9535, and the new mandatory standard GB 47739-2026; determines whether modules pass type certification and can be released from the factory). In summary, certification involves six key areas: Scope, Institutions, IEC 61215, CQC, “Top Runner” Program, and Mandatory Standards—ensuring comprehensive certification coverage.
IV.
Components
What to look for regarding components.
Key aspects to evaluate for each component: Junction Box—Zhongxi Testing (electrical safety performance: dielectric strength/withstand voltage tests, insulation resistance tests measuring resistance between live and accessible metal parts; mechanical structure: robust housing and internal structure); Connectors—new-pv (quality assessment: visual inspection for high-quality engineering plastic with hard, smooth texture; clear markings for brand, model, specifications, and ratings; precise interface geometry); Terminals—Qingxi Technology (mating force tests: 3–8N insertion, 2–6N withdrawal; mechanical strength: drum rotation test with no damage; fatigue tests: spring-terminal button compression and release cycles); Sealing—Beijian (waterproof sealing tests: compression set testing of sealing materials; interface tensile tests: applying axial tension to the cable-junction box connection; water immersion tests: full submersion for a specified duration); Cables—FRCABLE (conductor quality is critical; most TÜV-certified solar cables use tinned copper conductors for enhanced corrosion resistance); Backsheets—CQC (durability rating for PV module backsheet materials under the “Top Runner” program: Level 1 withstands 4,000 hours of combined light, water, temperature, and humidity stress; Level 2: 3,000 hours; Level 3: 2,000 hours)—Six key components to evaluate: junction box, connector, terminal, seal, cable, and backsheet.
V.
Trends
What to look for regarding trends.
Key trends to watch: MC4—SurgePV (MC4 connector crimping best practices; contact resistance <0.5 mΩ; temperature cycling -40°C to +85°C; IEC 60352-2 standards for solderless crimped connections); Lifespan—Portlandia (Genuine Tier 1 connectors, properly crimped and sealed, are designed for a 25–30 year service life; uncertified knock-offs often become brittle and crack after a few years of sun exposure); Standards—bn.wxhhcable (EN 50618/IEC 62930: primary European standards for PV cables rated up to 1500V DC; UL 4703: North American standard for PV wire); Aging—AIT (Accelerated aging tests verify material and component stability over time; electrical safety/risk minimization regarding short circuits; precise efficiency measurements); Defect Rate—Industrial Monitor Direct (IEC 62790 Clause 4.1 specifies a max temperature of 85°C for junction box connections; 0.18% defect rate is acceptable for a 6-month-old solar farm; industry "infant mortality" rates); Insulation—Suntree (XLPO cross-linked polyolefin insulation offers excellent resistance to UV, ozone, hydrolysis, and high temperatures up to 120°C; certifications include TUV EN 50618/IEC 62930 or UL 4703; operating range -40°C to +90°C). These six areas—MC4, lifespan, standards, aging, defect rates, and insulation—provide a comprehensive overview of current trends.
Conclusion
How can the quality of photovoltaic components be assessed? The conclusion is that the assessment relies on five key aspects: inspection, testing, certification, components, and trends.
Inspections—Zhongxi Institute (continuity checks for open circuits, cold solder joints, and poor contact); Group Standards (neat cable routing, securing, and sealing); Group Standards (secure mounting of module brackets and anti-rust coating/plating); Varistor Engineering (nameplate serial number traceability and visual inspection for glass cracks); Group Standards (weather-resistant, flame-retardant, double-insulated DC cables with flexible copper conductors); Qinghai Administration for Market Regulation (on-site EL imaging for hidden defects); Testing—Qingxi Technology (withstand voltage: 1500V AC for 1 minute without breakdown); Qingxi Technology (contact resistance ≤5mΩ; insulation resistance ≥1000MΩ); Xun Dao Testing (high/low-temperature cycling: 85°C and -40°C); Xun Dao Testing (salt spray corrosion test); Suntree (Hi-Pot: 3000V DC for 1 minute; contact resistance at 10A); Suntree (IP68: 1m water immersion for 30 minutes; 1000-hour UV aging); Certifications—State Administration for Market Regulation (PV product testing and certification scope: modules, inverters, and control equipment); State Administration for Market Regulation (certification body approval by CNCA and laboratory qualification accreditation); Fraunhofer ISE (IEC 61215 & IEC 61730: over 50 test methods); CQC (CQC53-471547 comprehensive quality grade certification); CQC (“Top Runner” program backsheet durability: Level 1 4000h, Level 2 3000h, Level 3 2000h); CAS Testing (IEC 61215, GB/T 9535, GB).
47739-2026 Mandatory Standard, CAS Testing); Components—Zhongxi Testing (junction box withstand voltage, insulation, and mechanical structure inspection), new-pv (connector material quality, clear markings, and precise interface dimensions), Qingxi Technology (insertion force 3–8N, withdrawal force 2–6N, fatigue testing), Beijian (junction box waterproof sealing and immersion testing), FRCABLE (corrosion resistance of tinned copper conductors), CQC (backsheet durability rating); Trends—SurgePV (MC4 contact resistance 0.5mΩ, temperature cycling -40°C to 85°C), Portlandia (tier-1 connectors with 25–30 year lifespan vs. non-certified brittle cracking), bn.wxhhcable (EN 50618 1500V DC, UL 4703
