How to Assess Solar Module Anti-PID Performance: What the Tests Are (IEC TS 62804-1:2025 — PID-Shunting in the Dark With a Chamber Method Whose Minimum Stress Is 60 °C/85% RH/96 h at Rated System Voltage and 65 °C or 85 °C Recommended for Harder Testing; PID-Polarization Under UV at 60 °C for 20 h; a UV Recovery Test; IEC 61215-2:2021 MQT 21; IEC TS 62804-1-1 for Delamination), What the Chamber Result Can Promise (NREL: Below 5% Loss at 60 °C/85% RH/96 h Matched No Field PID in 4–6 Florida Years; the Stress Levels Are Not Correlated With Natural Conditions), Which Mode Matters for Today's Cells (IEA PVPS 2025: PID-Shunting Not Seen in Current Cell Types; Polarization Is the Emerging Mode; a TOPCon Case Fell From 28% Loss Without UV to Below 3% With UV) and China's Adoption Status (GB/Z 117.101-2026 Issued; the Part 1 Adoption Is a Consultation Draft)

Short answer. Potential-induced degradation (PID) is power loss driven by the voltage between a module's cell circuit and ground; the 2014 IEA PVPS failure review describes it as affecting only a fraction of modules, only in strings of a given polarity to ground, more strongly at higher voltage, as a partly reversible polarisation effect in crystalline silicon that shunts cells and lowers fill factor, and as hard to see because early-stage loss is small at high irradiance and even massive PID often has no visual sign. The laboratory tests are now standardised. IEC TS 62804-1:2025 gives two dark methods for PID-shunting, two UV-illuminated methods for PID-polarization and a separate UV recovery test; IEC 61215-2:2021 added a PID detection test as MQT 21 to design qualification; IEC TS 62804-1-1:2020 covers the delamination mode separately. The Chinese rendering of the 2025 IEC text — a consultation draft that adopts it identically — states, for the environmental-chamber shunting method, a minimum stress level of a 60 °C ± 2 °C module, 85% ± 3% RH, 96 h at rated system voltage and polarity, recommends 65 °C and 85 °C where no degradation appears at 60 °C or more acceleration is sought, requires the level and duration to be stated in the report, and limits the document to crystalline cells with passivated dielectric layers (thin-film, tandem and heterojunction modules only by reference). What a pass promises is bounded by two statements. NREL's 2017 study found that modules with less than 5% loss at 60 °C/85% RH/96 h at nameplate bias showed no field PID over 4–6 years in Florida, suggesting that level as a pass/fail criterion good for at least five years there or in milder climates; the IEC text itself says the stress conditions have not been correlated with natural conditions and that the tighter ramp rules lowered the applied stress and invalidated the earlier correspondence. For current cell types the relevant mode has shifted: IEA PVPS Task 13's 2025 report says PID-shunting has not been observed in current cell types, PID-polarization is the emerging mode, a TOPCon module lost 28% without UV during the test but below 3% with UV, and a new mechanism was identified for SHJ modules with no field cases yet. A datasheet line reading "Anti-PID Guarantee — minimizes the chance of degradation caused by PID phenomena through optimization of cell production technology and material control", with no test condition or loss figure, is the example of a claim that still needs a report behind it. This guide reads the standards' abstracts, a Chinese consultation draft of the IEC text, two NREL preprints and two IEA PVPS reports; it quotes no manufacturer PID report or field audit.

1. The tests and what each one measures

Two scope points from the draft matter for module selection. The document applies to crystalline modules with passivated dielectric layers, where the mechanism is mobile ions acting on the field at the silicon surface; it does not apply to thin-film, tandem or heterojunction modules, for which it may be used as reference. And the test is to be run at the installation polarity allowed by the manufacturer's specification, because degradation has been seen in both positive- and negative-polarity strings depending on cell structure and materials.

CNWattHub reading: a PID report should therefore state five things — which method (a, b, c or d), the temperature level, the duration, the polarity, and the pre- and post-test power with the pass threshold used — and whether the sample was a passivated-dielectric crystalline cell to which the method applies. A report that says only "PID test passed" has not stated any of them.

2. What a chamber pass can promise

• The field correlation that exists. NREL's experiment with five module designs and multiple replicas found that modules passing a criterion of less than 5% power loss at 60 °C, 85% RH, 96 h and nameplate system-voltage bias showed no PID power loss over 4–6 years in Florida; the authors suggest that chamber level as a pass/fail criterion that helps ensure against system-voltage degradation in Florida or less stressful climates for at least 5 years.
• The caveat in the standard itself. The IEC text (as rendered in the Chinese draft) says the stress conditions have not been correlated with natural conditions; the Florida resistance was shown for modules tested with temperature, humidity and bias applied together at the start of the 96 h with no recovery step, but tighter ramp-rate and tolerance rules have since lowered the total applied stress and invalidated that correspondence, and the metal-foil grounding method's correlation with outdoor stress is unproven — hence the optional parameters above the basic level.
• Lifetime extrapolation. NREL's 2012 analysis compared outdoor degradation with chamber tests at three temperatures and 85% RH, fitted a lognormal model with failure at 80% of initial power, found an activation energy of 0.73 eV for the failure rate, and concluded that shunt-resistance measurements alone do not represent the extent of power degradation.
• Why older reports vary. The 2014 review records testing from 25 °C to 85 °C with grounding by humidity, wet towels, pastes, gels or foils; many companies used foil for 168 h at 25 °C, others 50–70 °C for shorter times, and no systematic outdoor testing then showed the equivalence of these levels or the lab-to-lab repeatability of foil tests.

CNWattHub reading: the two statements have to be held together. NREL's 2017 field link was found under the earlier, harsher application of the 60 °C/96 h stress; the IEC text says that link no longer holds under the tightened procedure. A pass at the minimum level is therefore a screening result for early-life shunting, not a statement of PID-free life in any climate; the supplier should be asked which level and duration were run and with what loss, and for a hot-humid site whether the 85 °C level was run at all.

3. Which mode matters for today's cells

CNWattHub reading: this is the reason the 2025 test added UV. A dark 96 h shunting test run on a TOPCon or PERC module answers a question that, on the 2025 report's reading, current cells largely no longer fail, while the polarization mode they can fail is sensitive to light — so a dark-only result on a passivated-contact module can be both a pass and uninformative. The report to ask for is the illuminated PID-p test with its rear-side UV level stated, because the rear default of 0.3 W/m² is an assumption that a bifacial module on a bright surface may exceed.

4. China's standard status

• GB/Z 117.101-2026 光伏组件 电势诱导衰减测试方法 第1-1部分：晶体硅组件 分层 was published on 4 January 2026 as a current national standardization guiding technical document under MIIT (electronics), identically adopting IEC TS 62804-1-1:2020 (the delamination part); its text was not read.
• The Part 1 adoption — GB/Z XXXX—202X/IEC TS 62804-1:2025 光伏组件 电势诱导衰减测试方法 第1部分：晶体硅组件 — exists as a consultation draft on the national standards platform, proposed by MIIT and assigned to SAC/TC 90, with Yingli, TÜV Rheinland Shanghai, CGC, CESI, JA Solar and Canadian Solar among the drafting bodies; it is not an issued standard and its wording may change.

CNWattHub reading: a Chinese test report that cites "GB/Z 117" should be read for which part — the issued 1-1 (delamination) or the draft Part 1 (power loss) — since only the first is in force, and a report run to the IEC TS 62804-1:2025 text directly is the cleaner reference for power loss.

5. An assessment sequence built from the sources

1. Cell type. Passivated-dielectric crystalline (in scope) versus thin-film, tandem or heterojunction (reference only).
2. Mode. Shunting (dark test) and polarization (UV test) both reported for passivated-contact cells; recovery test where polarization is found.
3. Level. 60 °C/85% RH/96 h as the minimum; 65 °C or 85 °C stated for hot-humid sites; duration and intensity in the report.
4. Polarity. The polarity the datasheet allows for installation, matched to the inverter topology.
5. Result. Power before and after, the threshold used (NREL's 5% is the published field-correlated level), not shunt resistance alone.
6. Field check. Low-irradiance performance and string-level comparison, since early-stage PID loss is small at high irradiance and even massive PID often has no visual sign.
7. Claims. A datasheet guarantee without a test condition or loss figure is a statement of design intent until the report is produced.

Scope limits

This guide reads the IEC webstore abstracts of IEC TS 62804-1:2025, IEC 61215-2:2021 and IEC TS 62804-1-1:2020 (texts not read), a Chinese consultation draft that identically adopts IEC TS 62804-1:2025 (quoted as the Chinese rendering of the IEC test, not as an issued Chinese standard), the records of GB/Z 117.101-2026, two NREL preprints (2012, 2017), the IEA PVPS Task 13 reports of 2014 and 2025, and one JinkoSolar datasheet. It quotes no manufacturer PID test report, field PID audit, warranty clause on PID or encapsulant specification. Not engineering, procurement or investment advice.