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54HPH-425M vs 66HPH-510M 10 of 18 identical Swap Change panels

Longi Solar LR5-54HPH-425M vs Longi Solar LR5-66HPH-510M

Longi Solar LR5-54HPH-425M
LR5-54HPH-425M
425 Wp 21.80 % PERC
Open panel page Datasheet PDF
VS
Longi Solar LR5-66HPH-510M
LR5-66HPH-510M
510 Wp 21.50 %
Open panel page Datasheet PDF
The verdict

8 differences, and they point both ways

The largest is rated power: 85 W more power. 10 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it.

See all 8 differences
How alike are they
10 of 18 comparable
parameters are identical
identical differs not published
01

What actually differs

8 of 18 parameters
Parameter 54HPH-425M 66HPH-510M Difference
Rated power 425 Wp 510 Wp 85 W more power
Weight 20.8 kg 25.3 kg 4.5 kg lighter
Open-circuit voltage 37.96 V 45.85 V 7.89 V apart
Module area 1.953 m² 2.373 m² 0.421 m² apart
Module efficiency 21.80 % 21.50 % 0.30 pp more efficient
Voltage at max power 31.94 V 38.68 V 6.74 V apart
Cell count 108 132 24 cells apart
Dimensions 1722x1134x30 mm 2093x1134x35 mm 1722x1134x30 mm vs 2093x1134x35 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.
54HPH-425M
13,774 kWh
66HPH-510M
16,529 kWh
Lifetime gap
2,755 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 54HPH-425M 66HPH-510M
Standard test conditions 25 °C 100.0% of rated power 425 W 510 W
Cool, bright day 40 °C 94.9% of rated power 403 W 484 W
Typical summer roof 55 °C 89.8% of rated power 382 W 458 W
Hot roof 70 °C 84.7% of rated power 360 W 432 W
03

Full specification

Parameter 54HPH-425M 66HPH-510M Difference
Power and efficiency
Rated power 425 Wp 510 Wp +85 W for 66HPH-510M
Module efficiency 21.80 % 21.50 % +0.30 pp for 54HPH-425M
Power density 217.6 Wp/m² 214.9 Wp/m² Effectively the same
Open-circuit voltage 37.96 V 45.85 V 7.89 V apart
Voltage at max power 31.94 V 38.68 V 6.74 V apart
Short-circuit current 14.08 A 14.05 A Effectively the same
Current at max power 13.31 A 13.19 A Effectively the same
Temperature
Temperature coefficient -0.340 %/°C -0.340 %/°C Same
Mechanical
Dimensions 1722x1134x30 mm 2093x1134x35 mm 1722x1134x30 mm vs 2093x1134x35 mm
Module area 1.953 m² 2.373 m² 0.421 m² apart
Weight 20.8 kg 25.3 kg -4.5 kg for 54HPH-425M
Weight per kWp 48.9 kg/kWp 49.6 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 108 132 24 cells apart
Bifacial No No Same
04

Against the whole database

14,005 panels
Efficiency
#7,022 vs #7,958
54HPH-425M leads by 936 places
Power density
#7,172 vs #8,033
54HPH-425M leads by 861 places
Heat behaviour
#8,778 vs #8,778
Tied - the same position in the database
Weight
#2,624 vs #3,154
54HPH-425M leads by 530 places
Warranty
#9,798 vs #9,798
Tied - the same position in the database
Overall
#10,867 vs #9,133
66HPH-510M leads by 1,734 places
05

More useful comparisons

Open the full database
Same series, other bin
Longi Solar LR5-54HPH-425M vs Longi Solar LR5-72HPH-565M
7 differences, the largest is rated power
Same series, other bin
Longi Solar LR5-54HPH-425M vs Longi Solar LR5-72HPH-560M
7 differences, the largest is rated power
Same series, other bin
Longi Solar LR5-54HPH-425M vs Longi Solar LR5-72HPH-555M
8 differences, the largest is rated power
Same series, other bin
Longi Solar LR5-54HPH-425M vs Longi Solar LR5-72HPH-550M
9 differences, the largest is rated power
Same series, other bin
Longi Solar LR5-54HPH-425M vs Longi Solar LR5-72HPH-545M
9 differences, the largest is module efficiency
Same series, other bin
Longi Solar LR5-54HPH-425M vs Longi Solar LR5-66HPH-515M
7 differences, the largest is rated power
06

Written summary

07

Questions about this pairing

Which panel is better: Longi Solar LR5-54HPH-425M or Longi Solar LR5-66HPH-510M?
According to our database: Longi Solar LR5-54HPH-425M has higher module efficiency (21.80% vs 21.50%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Longi Solar LR5-54HPH-425M and Longi Solar LR5-66HPH-510M?
Longi Solar LR5-54HPH-425M has a module efficiency of 21.80%, while Longi Solar LR5-66HPH-510M is 21.50%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Longi Solar LR5-54HPH-425M use vs Longi Solar LR5-66HPH-510M?
Longi Solar LR5-54HPH-425M uses PERC cells; Longi Solar LR5-66HPH-510M uses Monocrystalline. 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 LR5-54HPH-425M and Longi Solar LR5-66HPH-510M?
Longi Solar LR5-54HPH-425M has a 25 years power warranty; Longi Solar LR5-66HPH-510M 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 174 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.