pv magazine test: January 2024 results



After one month down for upgrades, the new array was brought online in mid-January, after which, 15 days of data were collected. Results from the first bifacial heterojunction (HJT) module in the test program are included. A new bifacial tunnel oxide passivated contact (TOPCon) module, from SEG Solar, was also added to the array.

A total of five products had to be removed from this month’s results, as two presented irregular performance, requiring investigation, and three temporarily lost connection with the data collection system. The main chart, above, shows the meteo station data (irradiance and ambient temperature) for the second half of January 2024. The average bifacial boost was 4.17% for January 2024. Bifacial boost is defined as the relative advantage of the average specific energy yield of all bifacial products compared to the average specific energy yield of all monofacial passivated emitter rear contact (PERC) products.

Monthly highlight

In the monofacial product ranking for January, Recom’s older technology, mono back-surface-field product got top rank while Aiko’s TOPCon back-contact (BC) panel product ranked last. This may seem counterintuitive but a look at the climatic conditions explains everything. For most of the days that data was collected the temperature was just above, or even below 0 C. Older-technology products have maximum power point (Pmax) temperature coefficients close to -0.45% per degree Celsius, as opposed to -0.35 % per degree Celsius for PERC, -0.29 % per degree Celsius for TOPCon, and -0.26 % per degree Celsius for Aiko’s BC. For older panels, operation in a cold environment increases the power faster than modules with “better” coefficients, and this explains the observed results for January.

Bifacial boost

All in Wh/WpTotal Sep. 2023Total Oct. 2023Total Nov. 2023Total Jan. 2024
Average monthly yield103.62102.6840.3641.62
Average monthly bifacial yield108.65105.9142.0842.37
Average monthly monofacial PERC yield99.28100.3740.2040.67
Operation days29281415
Average daily yield3.573.672.882.77
Average daily bifacial yield3.753.783.012.82
Average daily monofacial PERC yield3.423.582.872.71
Bifacial TOPCon boost10.88%5.74%5.22%4.51%
Bifacial HJT boostN/AN/AN/A3.66%
Bifacial PERC boost8.21%5.32%4.23%%3.88%
All technologies bifacial boost9.16%5.52%4.69%4.17%


Specific energy yield ranking of n-type bifacial TOPCon and HJT modules

#Installation monthProductTypeSample selection methodTotal
Jan. 2024 Wh/Wp
Jan. 2024 Rank
452023/8/15Trina TSM-NEG9RC.27n-TOPCon341.811
272023/6/5Jolywood JW-D72N-400n-TOPCon342.122
532023/11/15SEG SEG-575-BTA-BGn-TOPCon342.313
502023/9/1Astronergy CHSM72N(DG)/F-BH-580n-TOPCon342.094
512023/10/31Risen RSM132-8-700BHDGn-HJT342.165
422023/6/5DAS DH144NAn-TOPCon344.136


Specific energy yield ranking of bifacial PERC modules

#Installation monthProductTypeSample selection methodTotal
Jan. 2024 Wh/Wp
Jan. 2024 Rank
372021/5/1LONGi LR4-72HBD-445MBifacial PERC342.631
282020/4/15Risen RSM114-6-405BMDGBifacial PERC342.572
412022/12/18Tongwei TH550PMB6-58SDCBifacial PERC142.283
342021/7/1JA JAM72D20-445MBBifacial PERC241.534


Specific energy yield ranking of monofacial modules

#Installation monthProductTypeSample selection methodTotal
Jan. 2024 Wh/Wp
Pmax temp. coeff. (%/degree C)Jan 2024. Rank
102018/5/24Recom RCM-275-6MB-4-BB21Mono141.58-0.451
312020/10/1JA JAM60S10-345/MRPERC241.21-0.412
302020/7/7GCL GCL-M3/72H380Cast PERC140.98-0.383
202018/11/21Phono PS380MH-24/THPERC140.85-0.394
292020/7/7CSI CS3U-390MSPERC240.73-0.385
222019/5/4Znshine ZXP6-60-275/PMulti140.46-0.476
362021/11/20JA JAM72S30-540MRPERC239.89-0.357
442023/9/1AIKO A600-MAF72MwN-back contact339.80-0.268
Note: sample selection method categorization: Sample 1 randomly selected by CEA from a large production lot; Sample 2 purchased from the market by CEA; Sample 3 provided by supplier, without random selection


Energy yield measurements

  • The energy yield comparison among various technologies, including bifacial boost, has been analyzed using products installed after the beginning of 2019.
  • The energy yield was given in Wh produced per Wp of module generation capacity and calculated by dividing the energy produced by the module by its Pmax at standard test conditions (STC) for the module. This Pmax was the maximum STC power after a process of stabilization.
  • The results have been grouped into categories, per module type.
  • The bifacial boost depends on many parameters: bifaciality factor, installation geometry, albedo of the ground, the sun angle, and diffuse irradiance. The ground, in this case, is gray gravel.

Test cooperation

pv magazine test is a cooperative effort ­involving pv magazine, CEA, Gsolar and Hoymiles. All testing procedures are carried out at Gsolar’s test laboratory in Xi’an, China. CEA supervises these tests and designed both the indoor and outdoor testing procedures. 

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