Solar Panel Reliability Testing Equipment Guide

A PV module that works perfectly on day one means nothing if it loses 20% of its power in the first year. Reliability testing answers the question every module buyer asks: will it last? This guide covers the three types of reliability test equipment every PV lab and production line needs — light degradation, steady-state IV characterization, and MPPT tracking — and how TDM's Reliability and Durability Test series supports IEC 61215 and IEC 61730 qualification for both crystalline silicon and perovskite modules.

The three reliability tests every PV module must pass

Module certification under IEC 61215 (design qualification) and IEC 61730 (safety qualification) requires a battery of environmental stress tests. But from a measurement equipment perspective, three types of tests drive the majority of capital equipment decisions:

1. Light degradation (LID / LeTID)

Expose the module to continuous illumination (typically 1,000 W/m² at 25°C or elevated temperature) and measure power loss over time. LID (Light-Induced Degradation) stabilizes within days; LeTID (Light and elevated Temperature Induced Degradation) can progress for months and cause additional 5–15% loss. You need a light source that maintains stable irradiance and spectrum over weeks of continuous operation — not all solar simulators are built for endurance.

2. Steady-state IV characterization

Unlike a flash tester that captures a 10 ms IV curve, steady-state IV sweeps the module slowly enough to capture the true operating point — critical for high-capacitance modules (perovskite, HJT) where a fast flash gives artificially inflated efficiency numbers. Steady-state IV is also needed at multiple points during a degradation test to track how Voc, Jsc, FF, and Pmax evolve.

3. MPPT tracking under illumination

Maximum Power Point Tracking keeps the module at its optimal operating voltage while under continuous illumination. This is the most realistic reliability test: the module is illuminated, loaded at MPP, and its power output is logged continuously over hundreds or thousands of hours. Any degradation — from ion migration in perovskite to corrosion in crystalline silicon interconnects — shows up as a drop in MPP power that dark storage tests would miss entirely.

Why perovskite needs different reliability testing

The IEC 61215 standard was written for crystalline silicon modules. Perovskite modules fail differently, and they fail in ways that silicon-focused tests do not catch:

Failure mode	Silicon	Perovskite	Detected by
Light-induced degradation	B-O complex (LID), LeTID	Ion migration, phase segregation, halide redistribution	MPPT + periodic IV
Thermal degradation	Solder joint fatigue, encapsulant yellowing	Organic cation volatilization, interface delamination	Damp heat + IV
Humidity degradation	Corrosion of grid lines, PID	Hydrolysis of perovskite, electrode corrosion	Damp heat + EL imaging
Operational degradation	Gradual, well-characterized	Recovery effects, day-night cycling behavior	Long-duration MPPT

The critical insight: perovskite modules can show apparent recovery during dark periods — a module that looks degraded at the end of a light-soaking session may partially recover overnight. This makes continuous MPPT tracking under illumination the only test that gives a true picture of field performance.

TDM reliability testing equipment

SE910 PV Module Light Degradation Tester

The SE910 is TDM's dedicated light degradation test system. It provides continuous, stable illumination for LID and LeTID testing on full-size PV modules under IEC-compliant conditions.

Parameter	Specification
Application	Light degradation (LID/LeTID) testing
Module compatibility	Full-size crystalline silicon and perovskite modules
Standard compliance	IEC 61215, IEC 61730
Operation	Continuous illumination with stable spectrum

SE920 Steady-state PV Module IV & Degradation Tester

The SE920 adds steady-state IV characterization to the degradation test. It combines continuous illumination with a precision source-measure unit that sweeps the IV curve slowly enough to avoid capacitive artifacts — the gold standard for high-efficiency modules where every 0.1% of measured efficiency matters.

Parameter	Specification
Application	Steady-state IV + light degradation
Measurement	Voc, Jsc, FF, Pmax under continuous illumination
Key advantage	No capacitive artifact — true steady-state IV curve
Standard compliance	IEC 61215, IEC 61730

SE400 PVK MPPT Testing System

The SE400 is TDM's purpose-built MPPT reliability tester for perovskite modules. An A+A+A+ multi-band LED light source provides spectrum-tunable illumination while the MPPT tracker holds the module at its maximum power point and logs output continuously — for days, weeks, or the full 1,000-hour qualification run.

Parameter	Specification
Application	MPPT tracking under illumination (perovskite)
Light source	A+A+A+ multi-band LED
Measurement	Continuous MPP power logging + periodic IV sweeps
Duration	1,000+ hours continuous operation
Standard compliance	IEC 61215, IEC 61730 (perovskite adaptation)

How to choose: SE910 vs. SE920 vs. SE400

If you need to…	Choose
Run LID/LeTID tests on crystalline silicon modules with periodic external IV measurement	SE910
Run LID/LeTID + capture steady-state IV curves on the same instrument without moving the module	SE920
Run long-duration MPPT tracking on perovskite modules with tunable-spectrum LED illumination	SE400
Qualify modules to IEC 61215 + IEC 61730 in a test lab serving multiple technologies	SE920 + SE400

Why a complete reliability bench matters

The PV reliability testing equipment market is fragmented. Vendors that make excellent solar simulators for flash testing often do not offer long-duration degradation systems. Environmental chamber suppliers rarely provide MPPT trackers. And few platforms combine tunable-spectrum LED illumination with continuous MPPT logging for perovskite.

Engineers who need a complete reliability testing bench — light source, IV tracer, and MPPT tracker with one software interface — are often forced to integrate components from multiple suppliers. TDM's three-instrument lineup (SE910, SE920, SE400) is built to close that gap.

Get a technical consultation

Tell us your module technology, required standards, and testing throughput — our application engineers will recommend the right reliability test configuration and provide a detailed specification sheet.

Customized test configuration for your module type
IEC 61215 / IEC 61730 compliance guidance
On-site installation and calibration support

Browse the Reliability and Durability Test series, review SE910, SE920 and SE400, or contact TDM to submit an inquiry.

Frequently asked questions

What is the difference between IEC 61215 and IEC 61730?

IEC 61215 is the design qualification standard — it verifies that a module design can survive decades of outdoor exposure through accelerated tests (thermal cycling, damp heat, humidity freeze, UV exposure). IEC 61730 is the safety qualification standard — it covers electrical shock, fire, and mechanical hazards. A module needs both certifications to be sold in most markets. TDM's reliability test equipment is built to support both standards.

How long does a full IEC 61215 qualification test take?

The full IEC 61215 test sequence takes 3–6 months, depending on the module technology and the specific tests required. Light degradation testing (LID/LeTID) alone can take weeks to months under 1-sun illumination. MPPT testing at elevated temperature is typically 1,000 hours.

What is the difference between LID and LeTID?

LID (Light-Induced Degradation) is the rapid initial power loss seen in crystalline silicon modules, primarily caused by boron-oxygen complex formation. It stabilizes within days to weeks. LeTID (Light and elevated Temperature Induced Degradation) is a slower, temperature-dependent degradation mechanism that can continue for months and cause additional 5–15% power loss beyond LID. Testing for both requires long-duration illuminated exposure with periodic IV characterization.

Does perovskite require different reliability testing than crystalline silicon?

Yes — and this is still an active area of standardization. Perovskite modules show different degradation mechanisms (ion migration, phase segregation, interface degradation) that are not fully captured by silicon-focused IEC 61215 tests. MPPT tracking under illumination is especially important for perovskite because it reveals degradation that simple dark storage or thermal cycling misses. The SE400 is purpose-built for this — multi-band LED illumination with simultaneous MPPT tracking.

Which TDM instrument should I use for light degradation testing?

Start with the SE910 for dedicated light degradation testing on full-size modules. If you need simultaneous IV characterization during degradation, choose the SE920. For perovskite-specific MPPT tracking under illumination, the SE400 with A+A+A+ multi-band LED source is the right tool.

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