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590 XM+ vs 640 XL 11 of 19 identical Swap Change panels

Silfab SIL-590 XM+ vs Silfab SIL-640 XL

Silfab
SIL-590 XM+
590 Wp 22.80 % N-type Bifacial
Open panel page Datasheet PDF
VS
Silfab
SIL-640 XL
640 Wp 22.92 % N-type Bifacial
Open panel page Datasheet PDF
The verdict

640 XL leads on the differences that matter

The largest is rated power: 50 W more power. 11 of 19 comparable parameters are identical.

See all 8 differences
How alike are they
11 of 19 comparable
parameters are identical
identical differs
01

What actually differs

8 of 19 parameters
Parameter 590 XM+ 640 XL Difference
Rated power 590 Wp 640 Wp 50 W more power
Open-circuit voltage 52.50 V 57.76 V 5.26 V apart
Module area 2.581 m² 2.793 m² 0.212 m² apart
Cell count 144 156 12 cells apart
Voltage at max power 44.79 V 48.78 V 3.99 V apart
Weight per kWp 48.3 kg/kWp 46.1 kg/kWp 2.2 kg/kWp lighter
Weight 28.5 kg 29.5 kg 1.0 kg lighter
Dimensions 2278x1133x35 mm 2465x1133x35 mm 2278x1133x35 mm vs 2465x1133x35 mm
02

What it means on a roof

Thirty years of production
Each panel's own declared degradation curve, at 1,200 kWh/kWp a year
Same temp coeff. for both panels (-0.290 %/°C), so a warmer roof scales both curves by the same factor: the totals fall together and neither panel gains on the other.
590 XM+
19,830 kWh
640 XL
21,577 kWh
Lifetime gap
1,747 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 590 XM+ 640 XL
Standard test conditions 25 °C 100.0% of rated power 590 W 640 W
Cool, bright day 40 °C 95.7% of rated power 564 W 612 W
Typical summer roof 55 °C 91.3% of rated power 539 W 584 W
Hot roof 70 °C 87.0% of rated power 513 W 556 W
03

Full specification

Parameter 590 XM+ 640 XL Difference
Power and efficiency
Rated power 590 Wp 640 Wp +50 W for 640 XL
Module efficiency 22.80 % 22.92 % Effectively the same
Power density 228.6 Wp/m² 229.2 Wp/m² Effectively the same
Open-circuit voltage 52.50 V 57.76 V 5.26 V apart
Voltage at max power 44.79 V 48.78 V 3.99 V apart
Short-circuit current 13.91 A 13.76 A Effectively the same
Current at max power 13.17 A 13.12 A Effectively the same
Temperature
Temperature coefficient -0.290 %/°C -0.290 %/°C Same
Mechanical
Dimensions 2278x1133x35 mm 2465x1133x35 mm 2278x1133x35 mm vs 2465x1133x35 mm
Module area 2.581 m² 2.793 m² 0.212 m² apart
Weight 28.5 kg 29.5 kg -1.0 kg for 590 XM+
Weight per kWp 48.3 kg/kWp 46.1 kg/kWp -2.2 kg/kWp for 640 XL
Warranty and degradation
Product warranty 25 yrs 25 yrs Same
Performance warranty 30 yrs 30 yrs Same
Annual degradation 0.32 %/yr 0.30 %/yr Effectively the same
Technology
Cell technology N-type N-type Same
Cell type Monocrystalline Monocrystalline Same
Cell count 144 156 12 cells apart
Bifacial Yes Yes Same
04

Against the whole database

14,005 panels
Efficiency
#2,714 vs #2,350
640 XL leads by 364 places
Power density
#2,463 vs #2,379
640 XL leads by 84 places
Heat behaviour
#2,165 vs #2,165
Tied - the same position in the database
Weight
#2,190 vs #1,004
640 XL leads by 1,186 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#1,554 vs #650
640 XL leads by 904 places
05

More useful comparisons

Open the full database
Same series, other bin
Silfab
Silfab SIL-590 XM+ vs Silfab SIL-580-XM+-BIFACIAL
3 differences, the largest is module efficiency
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Silfab
Silfab SIL-590 XM+ vs Silfab SIL-570 XM+ BIFACIAL
4 differences, the largest is module efficiency
Same series, other bin
Silfab
Silfab SIL-590 XM+ vs Silfab SIL-570 XM+
4 differences, the largest is module efficiency
Same series, other bin
Silfab
Silfab SIL-590 XM+ vs Silfab SIL-530 XM
9 differences, the largest is rated power
Same series, other bin
Silfab
Silfab SIL-590 XM+ vs Silfab SIL-520 XM
11 differences, the largest is module efficiency
Same series, other bin
Silfab
Silfab SIL-590 XM+ vs Silfab SIL-520 QM
11 differences, the largest is module efficiency
06

Written summary

07

Questions about this pairing

Which panel is better: Silfab SIL-590 XM+ or Silfab SIL-640 XL?
According to our database: Silfab SIL-640 XL has higher module efficiency (22.92% vs 22.80%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Silfab SIL-590 XM+ and Silfab SIL-640 XL?
Silfab SIL-590 XM+ has a module efficiency of 22.80%, while Silfab SIL-640 XL is 22.92%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Silfab SIL-590 XM+ use vs Silfab SIL-640 XL?
Silfab SIL-590 XM+ uses N-type cells; Silfab SIL-640 XL uses N-type. Modern n-type technologies (TOPCon, HJT, BC) typically deliver higher efficiency and lower degradation compared to older PERC (p-type) cells.
What is the warranty on Silfab SIL-590 XM+ and Silfab SIL-640 XL?
Silfab SIL-590 XM+ has a 30 years power warranty; Silfab SIL-640 XL has a 30 years power warranty. The power warranty guarantees a minimum percentage of rated output at the end of the warranty period (typically 80-87%). Product (materials) warranties are usually shorter.
Are Silfab SIL-590 XM+ and Silfab SIL-640 XL bifacial panels?
Both Silfab SIL-590 XM+ and Silfab SIL-640 XL are bifacial - they capture reflected light from the ground, which can add 5-15% more annual energy on ground-mount or elevated rooftop installations with a light surface beneath.

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Every figure here is from the manufacturers' own datasheets - a dash means the value is not published, never an estimate. The thirty-year projection and the temperature scenarios are calculations from those figures, and each states its assumption above.