Longi Solar LR8-66HYD-670M vs Longi Solar LR7-72HVDF-645M
VS
The verdict
LR8-66HYD-670M leads on the differences that matter
The largest is module efficiency: 0.90 pp more efficient. 8 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it.
See all 10 differencesHow alike are they
8
of 18 comparable
parameters are identical
parameters are identical
identical
differs
not published
01
10 of 18 parameters
What actually differs
Parameter
LR8-66HYD-670M
LR7-72HVDF-645M
Difference
Module efficiency
24.80 %
23.90 %
0.90 pp more efficient
Power density
248.0 Wp/m²
238.8 Wp/m²
9.3 Wp/m² higher
Rated power
670 Wp
645 Wp
25 W more power
Product warranty
12 yrs
15 yrs
3 yrs longer
Open-circuit voltage
50.12 V
54.12 V
4.00 V apart
Short-circuit current
16.86 A
15.06 A
1.80 A apart
Cell technology
Back Contact
N-type
Back Contact vs N-type
Cell count
132
144
12 cells apart
Current at max power
16.19 A
14.41 A
1.78 A apart
Voltage at max power
41.38 V
44.77 V
3.39 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
LR7-72HVDF-645M
21,641 kWh
Lifetime gap
839 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
LR8-66HYD-670M
LR7-72HVDF-645M
Standard test conditions
25 °C
100.0% of rated power
670 W
645 W
Cool, bright day
40 °C
96.1% of rated power
644 W
620 W
Typical summer roof
55 °C
92.2% of rated power
618 W
595 W
Hot roof
70 °C
88.3% of rated power
592 W
570 W
03
Full specification
Parameter
LR8-66HYD-670M
LR7-72HVDF-645M
Difference
Power and efficiency
Rated power
670 Wp
645 Wp
+25 W for LR8-66HYD-670M
Module efficiency
24.80 %
23.90 %
+0.90 pp for LR8-66HYD-670M
Power density
248.0 Wp/m²
238.8 Wp/m²
+9.3 Wp/m² for LR8-66HYD-670M
Open-circuit voltage
50.12 V
54.12 V
4.00 V apart
Voltage at max power
41.38 V
44.77 V
3.39 V apart
Short-circuit current
16.86 A
15.06 A
1.80 A apart
Current at max power
16.19 A
14.41 A
1.78 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
51.9 kg/kWp
Effectively the same
Warranty and degradation
Product warranty
12 yrs
15 yrs
+3 yrs for LR7-72HVDF-645M
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
#351
LR8-66HYD-670M leads by 339 places
Power density
#14
vs
#356
LR8-66HYD-670M leads by 342 places
Heat behaviour
#511
vs
#511
Tied - the same position in the database
Weight
#3,317
vs
#5,361
LR8-66HYD-670M leads by 2,044 places
Warranty
#21
vs
#21
Tied - the same position in the database
Overall
#490
vs
#1,084
LR8-66HYD-670M leads by 594 places
05
Open the full database
More useful comparisons
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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
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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 LR7-72HVDF-645M?
According to our database: Longi Solar LR8-66HYD-670M has higher module efficiency (24.80% vs 23.90%). 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 LR7-72HVDF-645M?
Longi Solar LR8-66HYD-670M has a module efficiency of 24.80%, while Longi Solar LR7-72HVDF-645M is 23.90%. 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 LR7-72HVDF-645M?
Longi Solar LR8-66HYD-670M uses Back Contact cells; Longi Solar LR7-72HVDF-645M 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 LR7-72HVDF-645M?
Longi Solar LR8-66HYD-670M has a 30 years power warranty; Longi Solar LR7-72HVDF-645M 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 LR7-72HVDF-645M bifacial panels?
Both Longi Solar LR8-66HYD-670M and Longi Solar LR7-72HVDF-645M 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.