Longi Solar LR5-66HPH-515M vs Longi Solar LR5-54HPH-425M
VS
The verdict
7 differences, and they point both ways
The largest is rated power: 90 W more power. 11 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it.
See all 7 differencesHow alike are they
11
of 18 comparable
parameters are identical
parameters are identical
identical
differs
not published
01
7 of 18 parameters
What actually differs
Parameter
66HPH-515M
54HPH-425M
Difference
Rated power
515 Wp
425 Wp
90 W more power
Weight
25.3 kg
20.8 kg
4.5 kg lighter
Open-circuit voltage
46.00 V
37.96 V
8.04 V apart
Module area
2.373 m²
1.953 m²
0.421 m² apart
Voltage at max power
38.83 V
31.94 V
6.89 V apart
Cell count
132
108
24 cells apart
Dimensions
2093x1134x35 mm
1722x1134x30 mm
2093x1134x35 mm vs 1722x1134x30 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 (-0.340 %/°C), so a warmer roof scales both curves by the same factor: the totals fall together and neither panel gains on the other.
66HPH-515M
16,691 kWh
54HPH-425M
13,774 kWh
Lifetime gap
2,917 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
66HPH-515M
54HPH-425M
Standard test conditions
25 °C
100.0% of rated power
515 W
425 W
Cool, bright day
40 °C
94.9% of rated power
489 W
403 W
Typical summer roof
55 °C
89.8% of rated power
462 W
382 W
Hot roof
70 °C
84.7% of rated power
436 W
360 W
03
Full specification
Parameter
66HPH-515M
54HPH-425M
Difference
Power and efficiency
Rated power
515 Wp
425 Wp
+90 W for 66HPH-515M
Module efficiency
21.70 %
21.80 %
Effectively the same
Power density
217.0 Wp/m²
217.6 Wp/m²
Effectively the same
Open-circuit voltage
46.00 V
37.96 V
8.04 V apart
Voltage at max power
38.83 V
31.94 V
6.89 V apart
Short-circuit current
14.13 A
14.08 A
Effectively the same
Current at max power
13.27 A
13.31 A
Effectively the same
Temperature
Temperature coefficient
-0.340 %/°C
-0.340 %/°C
Same
Mechanical
Dimensions
2093x1134x35 mm
1722x1134x30 mm
2093x1134x35 mm vs 1722x1134x30 mm
Module area
2.373 m²
1.953 m²
0.421 m² apart
Weight
25.3 kg
20.8 kg
-4.5 kg for 54HPH-425M
Weight per kWp
49.1 kg/kWp
48.9 kg/kWp
Effectively the same
Warranty and degradation
Product warranty
12 yrs
12 yrs
Same
Performance warranty
25 yrs
25 yrs
Same
Annual degradation
0.55 %/yr
0.55 %/yr
Same
Technology
Cell technology
-
PERC
Not published by Longi Solar
Cell type
Monocrystalline
Monocrystalline
Same
Cell count
132
108
24 cells apart
Bifacial
No
No
Same
04
14,005 panels
Against the whole database
Efficiency
#7,421
vs
#7,022
54HPH-425M leads by 399 places
Power density
#7,426
vs
#7,172
54HPH-425M leads by 254 places
Heat behaviour
#8,778
vs
#8,778
Tied - the same position in the database
Weight
#2,764
vs
#2,624
54HPH-425M leads by 140 places
Warranty
#9,798
vs
#9,798
Tied - the same position in the database
Overall
#8,762
vs
#10,867
66HPH-515M leads by 2,105 places
05
Open the full database
More useful comparisons
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Longi Solar LR5-66HPH-515M vs Longi Solar LR5-72HPH-555M
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Longi Solar LR5-66HPH-515M vs Longi Solar LR5-72HPH-550M
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Longi Solar LR5-66HPH-515M vs Longi Solar LR5-66HPH-510M
One difference: module efficiency
06
Written summary
Checking cache...
07
Questions about this pairing
Which panel is better: Longi Solar LR5-66HPH-515M or Longi Solar LR5-54HPH-425M?
According to our database: Longi Solar LR5-54HPH-425M has higher module efficiency (21.80% vs 21.70%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Longi Solar LR5-66HPH-515M and Longi Solar LR5-54HPH-425M?
Longi Solar LR5-66HPH-515M has a module efficiency of 21.70%, while Longi Solar LR5-54HPH-425M is 21.80%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Longi Solar LR5-66HPH-515M use vs Longi Solar LR5-54HPH-425M?
Longi Solar LR5-66HPH-515M uses Monocrystalline cells; Longi Solar LR5-54HPH-425M uses PERC. 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 Longi Solar LR5-66HPH-515M and Longi Solar LR5-54HPH-425M?
Longi Solar LR5-66HPH-515M has a 25 years power warranty; Longi Solar LR5-54HPH-425M has a 25 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.
Shop prices: See 147 Longi Solar offers
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.