Top solar panel brands for reliability, quality and performance – pv magazine USA

The Renewable Energy Test Center (RETC) has released its 2024 Solar Module Index Report, assessing the reliability, quality and performance of solar panels.

Photovoltaic modules are subjected to various accelerated load tests to evaluate these parameters. Thanks to the benchmarking results, project stakeholders can select the products best suited to a specific environment, location or portfolio.

To identify the best of the best, RETC reviewed and ranked overall data distributions across three disciplines: quality, performance and reliability. Find your top performers at the end of this report.

Reliability

Ultraviolet resistance of the pad

Best contractors: JA Solar, Longi Solar, SolarSpace

Backsheet Ultraviolet Durability (BUDT) is a durability testing sequence designed to validate backplate glass-on-plate solar module designs for susceptibility to UV exposure and prevent backsheet-related failures. This BUDT sequence begins with 1,000 hours of exposure to moist heat to weaken the polymer bonds.

The featured top players did not experience any cracks in the pad during the test.

Damp heat test

Top performers: Astronergy, ES Foundry, Longi Solar, Runergy and Trina Solar

The RETC thresher test includes a moist heat test that exposes the modules to 2,000 hours, twice the time required for product certification. The test evaluates the module’s ability to withstand prolonged exposure to a humid, high-temperature environment. The test, which takes place in an environmental chamber, exposes modules to a controlled temperature of 85 C (185 F) and 85% relative humidity for a specified period of time.

RETC recognized contractors who experienced a decline of less than 2% following this exposure.

Hail durability

Best performers: JA Solar, Longi Solar

RETC’s hail strength test takes testing of UL and IEC standards a step further by exposing PV modules to greater kinetic impacts to reflect the risk posed by hail over a 25 or 30-year lifespan. In addition to ballistic impact testing, RETC performs thermal cycling and hot-spot testing to reveal potential long-term module degradation.

The best participants in this category sustained an effective kinetic energy of 20 joules or more. These modules successfully demonstrated resistance to a 45 mm (1.8 inch) diameter ice ball traveling at a terminal velocity of 30.7 m/s (68.7 mph).

Potentially induced degradation (PID)

Top Contractors: Astronergy, ES Foundry, GEP VN, Gstar, JA Solar, Longi Solar, Qcells, REC Solar, Runergy, SEG Solar, Silfab Solar, SolarSpace, Talesun, Trina Solar, VSUN Solar and Yingli Solar

Potential Induced Degradation (PID) resistance tests rack-mount modules in an environmental chamber that controls temperature and humidity and subjects them to a bias voltage of several hundred volts against the mounting structure for 192 hours (PID192 exposure). PID tests characterize the module’s resistance to degradation resulting from voltage and current leakage resulting from ion mobility between the semiconductor and other elements of the module packaging.

RETC required PV module models to withstand exposure to PID192 with a reduction in maximum power of less than 2%. At the other end of the spectrum, a maximum power degradation greater than or equal to 5% was considered a warning result.

Static and dynamic mechanical load testing

Top Contractors: Aptos Solar, Astronergy, ES Foundry, Gstar, JA Solar, Longi Solar, Runergy, Silfab Solar, SolarSpace, Trina Solar and Yingli Solar

This test subjects modules to 1,000 load cycles of +1,000 pascals and –1,000 pascals at a rate of three to seven cycles per minute. Measurements were made after this load test, characterized by electrical performance.

This year, RETC required solar module models to be resistant to SDML exposure with a reduction in maximum power of less than 2.5%. A maximum power degradation greater than or equal to 5% was considered a warning signal. In this test category, it was noted that 68% of the samples had high performing results, while 7% had red flag results.

Thermal cycle

Top Contractors: Aptos Solar, Astronergy, ES Foundry, Gstar, JA Solar, Longi Solar, Qcells, Runergy, SolarSpace, Trina Solar and Yingli Solar

The thermal cycling test requires modules to be cycled in an environmental chamber between two temperature extremes – 85 C (185 F) at the high end and –40 C (–40 F) at the low end. The RETC test covers 600 cycles, which is three times the 200 required for certification.

About 67% of the modules in this test achieved high-efficiency status with less than 2% power loss, while 9% of the brands tested had power losses of 5% or more.

Ultraviolet Induced Degradation (UVID)

Top performers: Trina Solar and VSUN Solar

UVID testing characterizes a photovoltaic module’s ability to withstand degradation caused by ultraviolet radiation. This optional test sequence exposes test samples to a UV exposure of 220 kWh/m2 (UV220), which is almost 15 times the UV exposure required for product certification.

The best devices withstand exposure to UV220 radiation with a reduction in maximum power of less than 2%. Warning modules that degraded by more than 5% accounted for 40% of the brands tested.

“Of concern is that we have observed double-digit power loss in some mass-produced, commercially available solar modules, indicating that these products can degrade by 10-16% within the first three years of field service,” RETC said.

Efficiency

Module performance

Top performers: Astronergy, Mission Solar, Qcells, REC Solar and Silfab Solar

Module conversion efficiency is determined by dividing the product’s maximum nameplate power rating under standard test conditions by its total aperture area.

RETC recognized manufacturers of solar module models with conversion efficiencies greater than 21% as high performers in the testing category. About 56% of the tested modules were considered high-performance.

Angle of incidence modifier

Top Contractors: Dehui Solar, ES Foundry, JA Solar, JinkoSolar, Longi Solar, Meyer Burger, Qcells, Runergy, Silfab Solar and SolarSpace

The angle of incidence modifier (IAM) is a performance characteristic that takes into account changes in the power output of a PV module based on changing angles of the sun relative to the plane of the array. To characterize IAM, RETC performs electrical characteristics tests at various incidence angles ranging from 0° to 90°.

Manufacturers of PV module models with an IAM greater than 88% at an incidence angle of 70° were listed as high performers in the test category.

LeTID Resistance

Top performers: Astronergy, Gstar, JinkoSolar, Longi Solar, Runergy, SEG Solar, Silfab Solar, SolarSpace, Talesun, Trina Solar, VSUN Solar, Waaree, Yingli Solar

Relatively new cell technologies may suffer long-term degradation due to exposure to light and elevated temperatures. This phenomenon, called light- and elevated temperature-induced degradation (LeTID), is investigated using a light annealing protocol followed by exposure to 75 C (167 F) for two 162-hour cycles to identify significant degradation (>5%). The test samples are then exposed to 75°C for 500 hours, followed by two additional cycles of 162 hours each.

The top-performing featured manufacturers showcased products with less than 0.5% potency loss after 486 hours of exposure.

LID resistance

Top Contractors: Astronergy, GEP VN, Gstar, JA Solar, JinkoSolar, Longi Solar, Meyer Burger, Qcells, Runergy, SEG Solar, Silfab Solar, SolarSpace, Talesun, Trina Solar, VSUN Solar, Waaree and Yingli Solar

Light-induced degradation (LID), or power loss due to exposure to sunlight, affects some types of photovoltaic cells but not others. Solar modules exposed to LID losses quickly lose performance within the first few hours or days of operation before stabilizing. RETC notes that LID resistance is highly correlated with cell type.

RETC required PV module models to withstand an LID sequence with a maximum power reduction of less than or equal to 0.5%.

Module performance

Top contractors: Auxin Solar, JA Solar, Longi Solar, Meyer Burger, Mission Solar, Qcells, REC Solar, Silfab Solar, Trina Solar, Yingli Solar

Module efficiency, or the percentage of incident solar energy converted to electricity, is a well-known and key measure of solar energy efficiency. This is closely related to cell technology and module design.

The 14 highest-scoring modules had an efficiency of 20% or more. The highest result was achieved by the TOPCon n-type cell with an efficiency of 25.8%, followed by a monocrystalline silicon module using heterojunction technology, which achieved an efficiency of 22.4%.

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