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Yingli YL645DF66 f/2
Yingli Brand review

YL645DF66 f/2

645 Wp PERC Bifacial 70%
ComparePV verdict

Middle of its segment, heavy for its output

Rank 4,257 of 14,005
Compare panels Datasheet PDF
Power (Wp)
645
Strong · top 7%
Efficiency (%)
20.80
Weak · bottom 18%
Density (Wp/m²)
207.6
Weak · bottom 12%
Temp (%/°C)
-0.340
Typical · median -0.340
Weight (kg)
38.4
Weak · 4.4 kg above median
Warranty (yrs)
30
Typical · median 30 yrs

The Yingli YLM 3.0 Plus 1 series is designed for high energy production on limited mounting surfaces, making it ideal where every square meter of roof or field space counts. These modules utilize p-type monocrystalline PERC solar cells, and their refined interconnection architecture ensures stable performance even under partial shading and uneven irradiance, common in many Polish installations. A key feature is the glass-glass construction, which enhances environmental resistance and facilitates maintaining parameters over a long period - a real advantage in projects exposed to wind, humidity, and temperature fluctuations. The series targets high reliability in challenging conditions thanks to high-quality lamination materials and robust construction. The YLM 3.0 Plus 1 is a solid choice for commercial and utility-scale PV projects, where dependable power generation and long-term durability take precedence over catalog specifications.

Ranking

217 panels in the segment PERC 600-650 W
Metric This panel Median Position in segment Overall rank
Module efficiency 20.80% 21.38% Weak · bottom 18% 10,457
Power density 207.6 213.8 Weak · bottom 12% 10,562
Temperature coefficient -0.340 -0.340 Typical 8,778
Weight per kWp 59.5 55.7 Weak · bottom 12% 12,193
Performance warranty 30 yrs 30 yrs Typical 21
Colour key Strong - top 25% Typical - middle 50% Weak - bottom 25%

Signals from the data

0 positive · 3 caution
Best for

Commercial and utility-scale.

Not ideal for

Weight-limited structures, roofs where every square metre has to count and tight roof space.

Watch-outs
59.5 kg per kWp

Bottom 12% of the PERC 600-650 W segment, against a median of 55.7.

207.6 watts per square metre

Bottom 12% of the PERC 600-650 W segment, against a median of 213.8.

20.80% module efficiency

Bottom 18% of the PERC 600-650 W segment, against a median of 21.38%.

Notes from the database
  • Module efficiency of 20.8% is 0.6pp below average for PERC 600-650W panels (median: 21.4%)
  • 207.6 W/m² power density is 6.2 W/m² below PERC 600-650W median (213.8 W/m²) - requires larger installation area
  • Temperature coefficient of -0.34%/°C matches the PERC 600-650W median
  • At 38.4 kg, this panel is 4.4 kg heavier than the PERC 600-650W median (34.0 kg) - more demanding for installation crews
  • Bifaciality factor of 70% can add 4-10% extra yield with reflective mounting surface

Specifications

Open datasheet PDF
Nominal power (Pmax) 645 Wp Nameplate at 1000 W/m², 25 °C
Module efficiency 20.80 % Weak Segment median 21.38%
Vmpp · Impp 37.30 V · 17.29 A Operating point at max power
Voc · Isc 45.10 V · 18.31 A Sizes the string length
Max system voltage 1500 V Longer strings than 1000 V modules
Dimensions 2384×1303×35 mm · 3.11 m² of roof
Weight 38.4 kg Weak Weak · 4.4 kg above median
Cells 132 · PERC Monocrystalline
Bifaciality 70 % Rear output as a share of front
Coefficient Pmax -0.340 %/°C Typical median -0.340 of its segment
Coefficient Voc · Isc -0.250 · 0.040 %/°C
NOCT 43 °C At 800 W/m², 20 °C ambient
Product warranty 12 years Hardware defects only
Performance warranty 30 years Typical median 30 yrs · median 30 yrs
End-of-warranty output 85.0 % Equals 548 W guaranteed
Degradation 2.00 → 0.45 % First year, then annual

Simulations

Live - change any input
Lifetime output & value
30 years at 1200 kWh/kWp/year and €0.50 per kWh
Power in year 30
-
Lifetime energy
-
Energy value
-
With bifacial gain
-

Degradation from this panel's own datasheet figures. No inverter, soiling or shading losses.

Heat losses
-0.340 %/°C against a segment median of -0.340
-
Bifacial gain
Rear gain over light concrete: -
-

Model: bifaciality × albedo × 0.6 view factor. A first-order estimate, not a yield simulation.

Filter these
Size
Panel Power Eff. Temp. Weight Difference
Yingli YL645DF66 f/2 645 W 20.80% -0.340 38.4 kg You are here
AIKO-A650-MAE72Mw 650 W 25.20% -0.260 27.0 kg Cooler, lighter, +4.4 pp
AIKO-A680-MDE72Mw 680 W 25.20% -0.260 29.0 kg Cooler, lighter, +4.4 pp
AIKO-A675-MDE72Mw 675 W 25.00% -0.260 29.0 kg Cooler, lighter, +4.2 pp
AIKO-A645-MAE72Mw 645 W 25.00% -0.260 27.0 kg Cooler, lighter, +4.2 pp
AIKO-A695-MAE78Dw 695 W 24.90% -0.260 34.5 kg +50 W, cooler, +4.1 pp
AIKO-G670-MCH72Mw 670 W 24.80% -0.260 28.2 kg Cooler, lighter, +4.0 pp
LR7-72HVHF-670M 670 W 24.80% -0.260 28.5 kg Cooler, lighter, +4.0 pp
YL650DF66 f/2 650 W 20.90% -0.340 38.4 kg Very close match
YL655DF66 f/2 655 W 21.10% -0.340 38.4 kg +10 W, +0.3 pp
YL660D-45f 1/2 660 W 21.20% -0.340 34.0 kg Lighter, +0.4 pp, -5 yr warranty
AIKO-A805-GRH78Dw 805 W 25.10% -0.260 39.8 kg +160 W, cooler, +4.3 pp
AIKO-A800-GRH78Dw 800 W 24.90% -0.260 39.8 kg +155 W, cooler, +4.1 pp
AIKO-A795-GRH78Dw 795 W 24.80% -0.260 39.8 kg +150 W, cooler, +4.0 pp
AIKO-A790-GRH78Dw 790 W 24.60% -0.260 39.8 kg +145 W, cooler, +3.8 pp
TSM-NEG21C.20Q-760 760 W 24.50% -0.260 38.3 kg +115 W, cooler, +3.7 pp
AIKO-A785-GRH78Dw 785 W 24.40% -0.260 39.8 kg +140 W, cooler, +3.6 pp

Found 1390 panels of the same or similar size to this one, within ±10 mm. See them here Found 1400 panels of the same or similar size to this one, within ±25 mm. See them here Found 1400 panels of the same or similar size to this one, within ±50 mm. See them here Found 1432 panels of the same or similar size to this one, within ±100 mm. See them here

Common questions

6 answered
What is the maximum power output of the Yingli YLM 3.0 Plus 1 panel?
The top variant of the YLM 3.0 Plus 1 series reaches up to 670 Wp, thanks to 132 large p-type monocrystalline PERC cells. This allows high energy yield from fewer modules, which meaningfully reduces installation time and mounting structure costs in commercial installations and utility-scale PV farms.
How does the glass-glass construction of the YLM 3.0 Plus 1 differ from standard glass-backsheet panels?
Unlike typical panels with a rear backsheet layer, the YLM 3.0 Plus 1 encapsulates its cells between two glass panes. This design better protects the cells from moisture, microcracks, and PID degradation, resulting in a slower power decline over time and greater resistance to harsh weather conditions such as strong wind or hail.
What warranty comes with the Yingli YLM 3.0 Plus 1 panels?
The manufacturer offers a 12-year product warranty along with a 30-year linear power output warranty. This means that after 30 years of operation, the panel should still retain the guaranteed minimum percentage of its initial output, a standard expectation for modern glass-glass modules from a tier 1 manufacturer.
Is the YLM 3.0 Plus 1 suited for large-scale PV farms or more for residential roofs?
This series is designed primarily for commercial installations and utility-scale PV farms, where predictable energy yield and long-term durability matter more than raw datasheet figures. Its large format and high unit power (up to 670 Wp) make it better suited to large mounting areas than to a typical single-family sloped roof.
Are the YLM 3.0 Plus 1 panels bifacial, generating power from the rear side?
No, the YLM 3.0 Plus 1 series uses standard monofacial PERC cell architecture. The glass-glass construction here is meant to boost durability and environmental resistance, not add rear-side power generation - this sets it apart from bifacial models in Yingli's lineup.
Who manufactures the YLM 3.0 Plus 1 panels, and is it a reliable tier 1 supplier?
The YLM 3.0 Plus 1 panels are made by Yingli, a Chinese manufacturer with decades of industry experience, classified as a tier 1 supplier. This reflects solid financial standing and proven manufacturing capacity, which matters when pursuing warranty claims over the multi-decade lifespan of a PV installation.
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