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520 XM BIFACIAL vs 580-XM+-BIFACIAL 9 of 18 identical Swap Change panels

Silfab SIL-520 XM BIFACIAL vs Silfab SIL-580-XM+-BIFACIAL

Silfab
SIL-520 XM BIFACIAL
520 Wp 21.90 % N-type Bifacial Incomplete
Open panel page Datasheet PDF
VS
Silfab
SIL-580-XM+-BIFACIAL
580 Wp 22.40 % N-type Bifacial
Open panel page Datasheet PDF
The verdict

580-XM+-BIFACIAL leads on the differences that matter

The largest is rated power: 60 W more power. 9 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it.

See all 9 differences
How alike are they
9 of 18 comparable
parameters are identical
identical differs not published
01

What actually differs

9 of 18 parameters
Parameter 520 XM BIFACIAL 580-XM+-BIFACIAL Difference
Rated power 520 Wp 580 Wp 60 W more power
Module efficiency 21.90 % 22.40 % 0.50 pp more efficient
Open-circuit voltage 47.52 V 52.27 V 4.75 V apart
Module area 2.377 m² 2.581 m² 0.204 m² apart
Power density 218.8 Wp/m² 224.7 Wp/m² 6.0 Wp/m² higher
Weight 26.2 kg 28.5 kg 2.3 kg lighter
Cell count 132 144 12 cells apart
Voltage at max power 40.48 V 44.27 V 3.79 V apart
Dimensions 2098x1133x35 mm 2278x1133x35 mm 2098x1133x35 mm vs 2278x1133x35 mm
02

What it means on a roof

Thirty years of production
Declared first-year losses, with 0.40% a year afterwards assumed for both panels, 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.
520 XM BIFACIAL
17,260 kWh
580-XM+-BIFACIAL
19,251 kWh
Lifetime gap
1,991 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 520 XM BIFACIAL 580-XM+-BIFACIAL
Standard test conditions 25 °C 100.0% of rated power 520 W 580 W
Cool, bright day 40 °C 95.7% of rated power 497 W 555 W
Typical summer roof 55 °C 91.3% of rated power 475 W 530 W
Hot roof 70 °C 87.0% of rated power 452 W 504 W
03

Full specification

Parameter 520 XM BIFACIAL 580-XM+-BIFACIAL Difference
Power and efficiency
Rated power 520 Wp 580 Wp +60 W for 580-XM+-BIFACIAL
Module efficiency 21.90 % 22.40 % +0.50 pp for 580-XM+-BIFACIAL
Power density 218.8 Wp/m² 224.7 Wp/m² +6.0 Wp/m² for 580-XM+-BIFACIAL
Open-circuit voltage 47.52 V 52.27 V 4.75 V apart
Voltage at max power 40.48 V 44.27 V 3.79 V apart
Short-circuit current 13.65 A 13.85 A Effectively the same
Current at max power 12.85 A 13.10 A Effectively the same
Temperature
Temperature coefficient -0.290 %/°C -0.290 %/°C Same
Mechanical
Dimensions 2098x1133x35 mm 2278x1133x35 mm 2098x1133x35 mm vs 2278x1133x35 mm
Module area 2.377 m² 2.581 m² 0.204 m² apart
Weight 26.2 kg 28.5 kg -2.3 kg for 520 XM BIFACIAL
Weight per kWp 50.4 kg/kWp 49.1 kg/kWp Effectively the same
Warranty and degradation
Product warranty 25 yrs 25 yrs Same
Performance warranty 30 yrs 30 yrs Same
Annual degradation - 0.30 %/yr Not published by Silfab
Technology
Cell technology N-type N-type Same
Cell type Monocrystalline Monocrystalline Same
Cell count 132 144 12 cells apart
Bifacial Yes Yes Same
04

Against the whole database

14,005 panels
Efficiency
#6,783 vs #4,774
580-XM+-BIFACIAL leads by 2,009 places
Power density
#6,837 vs #4,528
580-XM+-BIFACIAL leads by 2,309 places
Heat behaviour
#2,165 vs #2,165
Tied - the same position in the database
Weight
#3,761 vs #2,767
580-XM+-BIFACIAL leads by 994 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#4,485 vs #2,018
580-XM+-BIFACIAL leads by 2,467 places
05

More useful comparisons

Open the full database
Same series, other bin
Silfab
Silfab SIL-520 XM BIFACIAL vs Silfab SIL-520-XM-BIFACIAL
The same specification on paper
Same series, other bin
Silfab
Silfab SIL-580-XM+-BIFACIAL vs Silfab SIL-590 XM+
3 differences, the largest is module efficiency
Same series, other bin
Silfab
Silfab SIL-580-XM+-BIFACIAL vs Silfab SIL-570 XM+ BIFACIAL
3 differences, the largest is module efficiency
Same series, other bin
Silfab
Silfab SIL-580-XM+-BIFACIAL vs Silfab SIL-570 XM+
3 differences, the largest is module efficiency
Same series, other bin
Silfab
Silfab SIL-580-XM+-BIFACIAL vs Silfab SIL-530 XM
7 differences, the largest is rated power
Same series, other bin
Silfab
Silfab SIL-580-XM+-BIFACIAL vs Silfab SIL-520 XM
10 differences, the largest is rated power
06

Written summary

07

Questions about this pairing

Which panel is better: Silfab SIL-520 XM BIFACIAL or Silfab SIL-580-XM+-BIFACIAL?
According to our database: Silfab SIL-580-XM+-BIFACIAL has higher module efficiency (22.40% vs 21.90%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Silfab SIL-520 XM BIFACIAL and Silfab SIL-580-XM+-BIFACIAL?
Silfab SIL-520 XM BIFACIAL has a module efficiency of 21.90%, while Silfab SIL-580-XM+-BIFACIAL is 22.40%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Silfab SIL-520 XM BIFACIAL use vs Silfab SIL-580-XM+-BIFACIAL?
Silfab SIL-520 XM BIFACIAL uses N-type cells; Silfab SIL-580-XM+-BIFACIAL 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-520 XM BIFACIAL and Silfab SIL-580-XM+-BIFACIAL?
Silfab SIL-520 XM BIFACIAL has a 30 years power warranty; Silfab SIL-580-XM+-BIFACIAL 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-520 XM BIFACIAL and Silfab SIL-580-XM+-BIFACIAL bifacial panels?
Both Silfab SIL-520 XM BIFACIAL and Silfab SIL-580-XM+-BIFACIAL 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.