Longi Solar LR8-66HYD-670M vs Longi Solar LR7-72HVD-635M
VS
The verdict
LR8-66HYD-670M leads on the differences that matter
The largest is module efficiency: 1.30 pp more efficient. 7 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it.
See all 11 differencesHow alike are they
7
of 18 comparable
parameters are identical
parameters are identical
identical
differs
not published
01
11 of 18 parameters
What actually differs
Parameter
LR8-66HYD-670M
LR7-72HVD-635M
Difference
Module efficiency
24.80 %
23.50 %
1.30 pp more efficient
Power density
248.0 Wp/m²
235.1 Wp/m²
13.0 Wp/m² higher
Rated power
670 Wp
635 Wp
35 W more power
Product warranty
12 yrs
15 yrs
3 yrs longer
Short-circuit current
16.86 A
15.01 A
1.85 A apart
Open-circuit voltage
50.12 V
53.50 V
3.38 V apart
Cell technology
Back Contact
N-type
Back Contact vs N-type
Weight per kWp
50.0 kg/kWp
52.8 kg/kWp
2.8 kg/kWp lighter
Cell count
132
144
12 cells apart
Current at max power
16.19 A
14.32 A
1.87 A apart
Voltage at max power
41.38 V
44.36 V
2.98 V apart
02
What it means on a roof
Thirty years of production
A 1.0% first-year loss then 0.40% a year, assumed for both panels, at 1,200 kWh/kWp a year
Same temp coeff. for both panels (-0.260 %/°C), so a warmer roof scales both curves by the same factor: the totals fall together and neither panel gains on the other.
LR8-66HYD-670M
22,480 kWh
LR7-72HVD-635M
21,306 kWh
Lifetime gap
1,174 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
LR8-66HYD-670M
LR7-72HVD-635M
Standard test conditions
25 °C
100.0% of rated power
670 W
635 W
Cool, bright day
40 °C
96.1% of rated power
644 W
610 W
Typical summer roof
55 °C
92.2% of rated power
618 W
585 W
Hot roof
70 °C
88.3% of rated power
592 W
561 W
03
Full specification
Parameter
LR8-66HYD-670M
LR7-72HVD-635M
Difference
Power and efficiency
Rated power
670 Wp
635 Wp
+35 W for LR8-66HYD-670M
Module efficiency
24.80 %
23.50 %
+1.30 pp for LR8-66HYD-670M
Power density
248.0 Wp/m²
235.1 Wp/m²
+13.0 Wp/m² for LR8-66HYD-670M
Open-circuit voltage
50.12 V
53.50 V
3.38 V apart
Voltage at max power
41.38 V
44.36 V
2.98 V apart
Short-circuit current
16.86 A
15.01 A
1.85 A apart
Current at max power
16.19 A
14.32 A
1.87 A apart
Temperature
Temperature coefficient
-0.260 %/°C
-0.260 %/°C
Same
Mechanical
Dimensions
2382x1134x30 mm
2382x1134x30 mm
Same
Module area
2.701 m²
2.701 m²
Same
Weight
33.5 kg
33.5 kg
Same
Weight per kWp
50.0 kg/kWp
52.8 kg/kWp
-2.8 kg/kWp for LR8-66HYD-670M
Warranty and degradation
Product warranty
12 yrs
15 yrs
+3 yrs for LR7-72HVD-635M
Performance warranty
30 yrs
30 yrs
Same
Annual degradation
-
0.35 %/yr
Not published by Longi Solar
Technology
Cell technology
Back Contact
N-type
Back Contact vs N-type
Cell type
Monocrystalline
Monocrystalline
Same
Cell count
132
144
12 cells apart
Bifacial
Yes
Yes
Same
04
14,005 panels
Against the whole database
Efficiency
#12
vs
#716
LR8-66HYD-670M leads by 704 places
Power density
#14
vs
#741
LR8-66HYD-670M leads by 727 places
Heat behaviour
#511
vs
#511
Tied - the same position in the database
Weight
#3,317
vs
#6,429
LR8-66HYD-670M leads by 3,112 places
Warranty
#21
vs
#21
Tied - the same position in the database
Overall
#490
vs
#1,462
LR8-66HYD-670M leads by 972 places
05
Open the full database
More useful comparisons
Same series, other bin
Longi Solar LR8-66HYD-670M vs Longi Solar LR8-66HYD-665M
One difference: module efficiency
Same series, other bin
Longi Solar LR8-66HYD-670M vs Longi Solar LR8-66HYD-660M
3 differences, the largest is module efficiency
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Longi Solar LR8-66HYD-670M vs Longi Solar LR7-72HYD-660M
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Longi Solar LR8-66HYD-670M vs Longi Solar LR8-66HYD-655M
3 differences, the largest is module efficiency
Same series, other bin
Longi Solar LR8-66HYD-670M vs Longi Solar LR7-72HYD-655M
9 differences, the largest is module efficiency
Same series, other bin
Longi Solar LR8-66HYD-670M vs Longi Solar LR8-66HYD-650M
3 differences, the largest is module efficiency
06
Written summary
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07
Questions about this pairing
Which panel is better: Longi Solar LR8-66HYD-670M or Longi Solar LR7-72HVD-635M?
According to our database: Longi Solar LR8-66HYD-670M has higher module efficiency (24.80% vs 23.50%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Longi Solar LR8-66HYD-670M and Longi Solar LR7-72HVD-635M?
Longi Solar LR8-66HYD-670M has a module efficiency of 24.80%, while Longi Solar LR7-72HVD-635M is 23.50%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Longi Solar LR8-66HYD-670M use vs Longi Solar LR7-72HVD-635M?
Longi Solar LR8-66HYD-670M uses Back Contact cells; Longi Solar LR7-72HVD-635M 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 Longi Solar LR8-66HYD-670M and Longi Solar LR7-72HVD-635M?
Longi Solar LR8-66HYD-670M has a 30 years power warranty; Longi Solar LR7-72HVD-635M 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 Longi Solar LR8-66HYD-670M and Longi Solar LR7-72HVD-635M bifacial panels?
Both Longi Solar LR8-66HYD-670M and Longi Solar LR7-72HVD-635M 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.
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.