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LR7-72HYD-660M vs LR8-66HYD-670M 9 of 18 identical Swap Change panels

Longi Solar LR7-72HYD-660M vs Longi Solar LR8-66HYD-670M

Longi Solar LR7-72HYD-660M
LR7-72HYD-660M
660 Wp 24.40 % N-type Bifacial
VS
Longi Solar LR8-66HYD-670M
LR8-66HYD-670M
670 Wp 24.80 % Back Contact Bifacial Incomplete
The verdict

LR8-66HYD-670M leads on the differences that matter

The largest is module efficiency: 0.40 pp more efficient. 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 LR7-72HYD-660M LR8-66HYD-670M Difference
Module efficiency 24.40 % 24.80 % 0.40 pp more efficient
Open-circuit voltage 54.42 V 50.12 V 4.30 V apart
Short-circuit current 15.30 A 16.86 A 1.56 A apart
Cell technology N-type Back Contact N-type vs Back Contact
Power density 244.3 Wp/m² 248.0 Wp/m² 3.7 Wp/m² higher
Rated power 660 Wp 670 Wp 10 W more power
Cell count 144 132 12 cells apart
Voltage at max power 45.07 V 41.38 V 3.69 V apart
Current at max power 14.65 A 16.19 A 1.54 A 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.
LR7-72HYD-660M
22,144 kWh
LR8-66HYD-670M
22,480 kWh
Lifetime gap
336 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario LR7-72HYD-660M LR8-66HYD-670M
Standard test conditions 25 °C 100.0% of rated power 660 W 670 W
Cool, bright day 40 °C 96.1% of rated power 634 W 644 W
Typical summer roof 55 °C 92.2% of rated power 609 W 618 W
Hot roof 70 °C 88.3% of rated power 583 W 592 W
03

Full specification

Parameter LR7-72HYD-660M LR8-66HYD-670M Difference
Power and efficiency
Rated power 660 Wp 670 Wp +10 W for LR8-66HYD-670M
Module efficiency 24.40 % 24.80 % +0.40 pp for LR8-66HYD-670M
Power density 244.3 Wp/m² 248.0 Wp/m² +3.7 Wp/m² for LR8-66HYD-670M
Open-circuit voltage 54.42 V 50.12 V 4.30 V apart
Voltage at max power 45.07 V 41.38 V 3.69 V apart
Short-circuit current 15.30 A 16.86 A 1.56 A apart
Current at max power 14.65 A 16.19 A 1.54 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 50.8 kg/kWp 50.0 kg/kWp Effectively the same
Warranty and degradation
Product warranty 12 yrs 12 yrs Same
Performance warranty 30 yrs 30 yrs Same
Annual degradation 0.35 %/yr - Not published by Longi Solar
Technology
Cell technology N-type Back Contact N-type vs Back Contact
Cell type Monocrystalline Monocrystalline Same
Cell count 144 132 12 cells apart
Bifacial Yes Yes Same
04

Against the whole database

14,005 panels
Efficiency
#99 vs #12
LR8-66HYD-670M leads by 87 places
Power density
#88 vs #14
LR8-66HYD-670M leads by 74 places
Heat behaviour
#511 vs #511
Tied - the same position in the database
Weight
#4,172 vs #3,317
LR8-66HYD-670M leads by 855 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#817 vs #490
LR8-66HYD-670M leads by 327 places
05

More useful comparisons

Open the full database
Same series, other bin
Longi Solar LR7-72HYD-660M vs Longi Solar LR7-72HYD-655M
One difference: module efficiency
Same series, other bin
Longi Solar LR7-72HYD-660M vs Longi Solar LR7-72HYD-650M
3 differences, the largest is module efficiency
Same series, other bin
Longi Solar LR7-72HYD-660M vs Longi Solar LR7-72HYD-645M
3 differences, the largest is module efficiency
Same series, other bin
Longi Solar LR7-72HYD-660M vs Longi Solar LR7-72HYD-640M
3 differences, the largest is module efficiency
Same series, other bin
Longi Solar LR7-72HYD-660M vs Longi Solar LR7-72HYD-635M
3 differences, the largest is module efficiency
Same series, other bin
Longi Solar LR7-72HYD-660M vs Longi Solar LR7-72HYD-630M
4 differences, the largest is module efficiency
06

Written summary

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07

Questions about this pairing

Which panel is better: Longi Solar LR7-72HYD-660M or Longi Solar LR8-66HYD-670M?
According to our database: Longi Solar LR8-66HYD-670M has higher module efficiency (24.80% vs 24.40%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Longi Solar LR7-72HYD-660M and Longi Solar LR8-66HYD-670M?
Longi Solar LR7-72HYD-660M has a module efficiency of 24.40%, while Longi Solar LR8-66HYD-670M is 24.80%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Longi Solar LR7-72HYD-660M use vs Longi Solar LR8-66HYD-670M?
Longi Solar LR7-72HYD-660M uses N-type cells; Longi Solar LR8-66HYD-670M uses Back Contact. 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 LR7-72HYD-660M and Longi Solar LR8-66HYD-670M?
Longi Solar LR7-72HYD-660M has a 30 years power warranty; Longi Solar LR8-66HYD-670M 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 LR7-72HYD-660M and Longi Solar LR8-66HYD-670M bifacial panels?
Both Longi Solar LR7-72HYD-660M and Longi Solar LR8-66HYD-670M 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.