How to Assess Solar Module Warranty and Insurance: What Two Chinese Manufacturers' Warranties Actually Promise (Trina 10/12/15-Year Product and 25/30-Year Power; Jinko 12/15/25-Year Product and 30-Year Power), the Remedies and Exclusions, MIIT's Degradation Ceilings (2024 Norms and 2026 Draft), Two Chinese Insurers' Clauses (Manufacturer-Side Warranty Liability and Owner-Side Generation Loss), and the Product Quality Law

Short answer. A module warranty is two promises with different clocks. In Trina Solar's global limited warranty the product warranty runs 10, 12 or 15 years by product group (defects in material, workmanship or manufacture that materially impede power generation; glass breakage without external cause), and the clock starts on the earlier of installation or three months after delivery. The power warranty on front-side output runs 25 years for back-sheet and 30 years for dual-glass products (certain bifacial models carry a separate 30-year backside warranty), with a per-product-group curve — for the N-type mono products of Sec. 1) c) (i), 1.0% in year one and an average annual decline of no more than 0.4% to 89.4% at year 25 — and measurement-system uncertainty is to be included in the STC measurement. JinkoSolar's Chinese warranty for contracts from 26 July 2024 tabulates 12-, 15- or 25-year product and 30-year power cover per model (Tiger Neo 1.00%/0.40% to 87.40% at year 30). The remedy is the manufacturer's choice in both documents; removal and reinstallation costs stay with the buyer; and both exclude consequential losses (Trina to the extent the law allows, naming loss of power generation; Jinko naming loss of profits and revenue). MIIT's 2024 norms cap module degradation at 2%/0.55%/15% (P-type) and 1%/0.4%/11% (N-type) over 25 years and encourage 25-year power and 12-year materials warranties; the October 2026 draft would tighten this. Two Chinese insurers write cover around the warranty: Yanzhao's product quality and power compensation liability clause insures the manufacturer's warranty obligation for an insurance period of 25 years unless agreed otherwise (never beyond the warranty's own scope), and CPIC's 2025 project clause pays an owner's generation loss from defect-caused equipment quality problems and defect-caused above-warranty degradation but excludes what a supplier or other contract must pay. This guide reads those documents; it quotes no claim statistic, premium or court case.

1. The two warranties, side by side

CNWattHub arithmetic, for illustration: a 30-year curve of 1.0% in year one and 0.4% a year thereafter gives 100 − 1.0 − 29 × 0.4 = 87.4%, the figure in Jinko's Tiger Neo row. Trina's N-type 25-year curve gives 100 − 1.0 − 24 × 0.4 = 89.4%.

Three points of reading. First, both documents fold measurement uncertainty into the comparison of measured STC power with the curve, so the laboratory's stated tolerance matters as much as the curve itself. Second, both documents make the remedy the manufacturer's choice, while Trina's text notes that statutory rights outside the warranty may exist. Third, Trina's exclusions reach back to handling and transport, and its warranty is granted to the first customer installing the modules for its own use and only while they remain at the original place of installation — points that interact with resale and relocation.

2. MIIT's norms: a guiding document with degradation ceilings

MIIT's 2024 PV manufacturing industry norms — a guiding document, by their own preamble, without the character of a mandatory precondition for administrative approval — set degradation ceilings for module products — P-type crystalline silicon: first year ≤2%, then ≤0.55% a year, ≤15% over 25 years; N-type: ≤1%, ≤0.4%, ≤11%; thin film: ≤4%, ≤0.4%, ≤14% — and encourage a module power warranty of at least 25 years, a workmanship and materials warranty of at least 12 years and an inverter warranty of at least 5 years. The October 2026 consultation draft of the 2026 norms would add a coupled environmental-stress degradation ceiling of 8.6% and apply the 1%/0.4%/11% figures to crystalline silicon modules generally (thin film ≤4% first year, ≤0.4% a year), while keeping the encouraged 25/12/5-year warranty periods.

CNWattHub reading: the N-type rows of both warranties (1%/0.4%) match the 2024 N-type ceiling, while Trina's P-type poly row (2.5%, 0.65%) sits above the 2024 P-type ceiling (2%, 0.55%) — a reminder that a warranty curve is a contract term and the norms are a guiding document for manufacturers, not terms of any sale. Jinko's 12-year models and Trina's 10/12/15-year groups bracket the encouraged 12-year materials period.

3. What counts as a failure, and what degradation is 'within warranty'

IEA PVPS Task 13 defines a module failure as an effect that degrades power in a way not reversed by normal operation, or creates a safety issue (a purely cosmetic issue without either consequence is not a failure), says a failure is relevant for the warranty when it occurs under conditions the module normally experiences, and excludes problems caused by mishandling or the local environment such as soiling or lightning. Its 2021 risk-quantification report grades a defect's expected loss — estimated at component level, assuming no mitigation — from no degradation, through below detection limit (<2–3%), within warranty (<0.7–1%/year) and outside warranty (>0.7–1%/year), to catastrophic (>3%/year). Its 2021 service-life report warns that the lifetimes and degradation rates used in yield estimates are mostly averages from older systems or data sheets, not system-specific, and that models typically assume linear degradation although field degradation is typically non-linear. IEC 61215-1:2021, the design-qualification standard whose series Jinko's warranty cites for power measurement, says itself that useful service life depends on design, environment and operation and that test results are not a quantitative prediction of lifetime.

CNWattHub reading: a qualified module is not a 25-year promise by the standard; the promise is the warranty, and the warranty's curve is what an insurer backs.

4. The insurance behind the warranty

Two Chinese clauses show the two sides of the market.

Manufacturer side. Yanzhao Property Insurance's PV module product quality and power compensation liability clause insures the manufacturer or seller, with the end user as rights-holder; unless agreed otherwise the policy period is one year and the insurance period 25 years; the insurer pays, within the agreed limit, the repair, replacement, return or power-shortfall compensation that the insured owes under its limited warranty because of raw-material defects or manufacturing/workmanship defects; the warranty must be reviewed and filed with the insurer in advance; and cover never exceeds the warranty's own scope. Mechanics: a waiting period from the invoice date, per-occurrence and aggregate limits and a deductible agreed in the policy, reporting of each sales contract (serial numbers, invoice date, test reports and more), an insurer's right to sample-check reported modules at random, and liability determined on a test report from a mutually recognised third-party testing body — the original pre-shipment tester where there was one, in the original test environment.

Owner side. CPIC's 2025 project-specific additional clause (for CHN Energy projects) attaches to a generation-revenue policy and pays generation loss from quality problems of key equipment (modules, controllers, inverters) caused by raw-material, manufacturing or workmanship defects, and from module degradation that is caused by such defects and exceeds the limited warranty's promise, with the limit computed from the gap between actual and warranted power and the policy's expected generation; it excludes what a supplier or third party must pay under a repair or warranty arrangement, losses recoverable under other contracts, external causes, transport and storage losses, design errors, defects known at inception, indirect losses from power reduction and quality problems the insured had accepted.

CNWattHub reading: the two clauses are complementary, not overlapping — the manufacturer policy funds the warranty obligation itself, and the owner policy sits behind the warranty and excludes what the warranty should pay. An owner checking 'insured warranty' should ask which side the policy is on, who the rights-holder is, whether the warranty text was filed with the insurer, and what the waiting period and limits are.

5. The statutory backstop

China's Product Quality Law makes producers responsible for the quality of their products and obliges sellers to repair, replace or take back a sold product that lacks the use performance it should have (unless stated in advance), does not conform to the standard marked on it or its packaging, or does not match the quality shown by its description or sample, with recourse against the producer or supplier. CNWattHub reading: the warranties are contractual add-ons to this duty, and Trina's text itself says statutory rights outside the warranty may exist.

6. Reading table

Scope limits

This guide reads two manufacturers' warranty documents (no other manufacturer's document was read), two insurers' clause texts (one of them project-specific), MIIT's 2024 norms and 2026 draft, three IEA PVPS reports and the Product Quality Law. It quotes no premium, loss ratio, claim statistic, court or arbitration decision, and no Jinko warranty start-date or remedy wording beyond what is cited. Standards texts (IEC 61215-2, IEC 60904) were not read.