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LR8-66HYD-670M vs LR7-60HVH-555M 4 of 18 identical Swap Change panels

Longi Solar LR8-66HYD-670M vs Longi Solar LR7-60HVH-555M

Longi Solar LR8-66HYD-670M
LR8-66HYD-670M
670 Wp 24.80 % Back Contact Bifacial Incomplete
Open panel page Datasheet PDF
VS
Longi Solar LR7-60HVH-555M
LR7-60HVH-555M
555 Wp 24.60 % N-type
Open panel page Datasheet PDF
The verdict

14 differences, and they point both ways

The largest is rated power: 115 W more power. 4 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it.

See all 14 differences
How alike are they
4 of 18 comparable
parameters are identical
identical differs not published
01

What actually differs

14 of 18 parameters
Parameter LR8-66HYD-670M LR7-60HVH-555M Difference
Rated power 670 Wp 555 Wp 115 W more power
Weight 33.5 kg 25.0 kg 8.5 kg lighter
Product warranty 12 yrs 15 yrs 3 yrs longer
Open-circuit voltage 50.12 V 45.18 V 4.94 V apart
Module area 2.701 m² 2.257 m² 0.445 m² apart
Weight per kWp 50.0 kg/kWp 45.0 kg/kWp 5.0 kg/kWp lighter
Short-circuit current 16.86 A 15.55 A 1.31 A apart
Cell technology Back Contact N-type Back Contact vs N-type
Module efficiency 24.80 % 24.60 % 0.20 pp more efficient
Cell count 132 120 12 cells apart
Voltage at max power 41.38 V 37.41 V 3.97 V apart
Bifacial Yes No Yes vs No
Current at max power 16.19 A 14.84 A 1.35 A apart
Dimensions 2382x1134x30 mm 1990x1134x30 mm 2382x1134x30 mm vs 1990x1134x30 mm
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
LR7-60HVH-555M
18,621 kWh
Lifetime gap
3,859 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario LR8-66HYD-670M LR7-60HVH-555M
Standard test conditions 25 °C 100.0% of rated power 670 W 555 W
Cool, bright day 40 °C 96.1% of rated power 644 W 533 W
Typical summer roof 55 °C 92.2% of rated power 618 W 512 W
Hot roof 70 °C 88.3% of rated power 592 W 490 W
03

Full specification

Parameter LR8-66HYD-670M LR7-60HVH-555M Difference
Power and efficiency
Rated power 670 Wp 555 Wp +115 W for LR8-66HYD-670M
Module efficiency 24.80 % 24.60 % +0.20 pp for LR8-66HYD-670M
Power density 248.0 Wp/m² 245.9 Wp/m² Effectively the same
Open-circuit voltage 50.12 V 45.18 V 4.94 V apart
Voltage at max power 41.38 V 37.41 V 3.97 V apart
Short-circuit current 16.86 A 15.55 A 1.31 A apart
Current at max power 16.19 A 14.84 A 1.35 A apart
Temperature
Temperature coefficient -0.260 %/°C -0.260 %/°C Same
Mechanical
Dimensions 2382x1134x30 mm 1990x1134x30 mm 2382x1134x30 mm vs 1990x1134x30 mm
Module area 2.701 m² 2.257 m² 0.445 m² apart
Weight 33.5 kg 25.0 kg -8.5 kg for LR7-60HVH-555M
Weight per kWp 50.0 kg/kWp 45.0 kg/kWp -5.0 kg/kWp for LR7-60HVH-555M
Warranty and degradation
Product warranty 12 yrs 15 yrs +3 yrs for LR7-60HVH-555M
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 132 120 12 cells apart
Bifacial Yes No Yes vs No
04

Against the whole database

14,005 panels
Efficiency
#12 vs #51
LR8-66HYD-670M leads by 39 places
Power density
#14 vs #70
LR8-66HYD-670M leads by 56 places
Heat behaviour
#511 vs #511
Tied - the same position in the database
Weight
#3,317 vs #604
LR7-60HVH-555M leads by 2,713 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#490 vs #2,248
LR8-66HYD-670M leads by 1,758 places
05

More useful comparisons

Open the full database
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
Same series, other bin
Longi Solar LR8-66HYD-670M vs Longi Solar LR7-72HYD-660M
9 differences, the largest is module efficiency
Same series, other bin
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

07

Questions about this pairing

Which panel is better: Longi Solar LR8-66HYD-670M or Longi Solar LR7-60HVH-555M?
According to our database: Longi Solar LR8-66HYD-670M has higher module efficiency (24.80% vs 24.60%). 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 LR7-60HVH-555M?
Longi Solar LR8-66HYD-670M has a module efficiency of 24.80%, while Longi Solar LR7-60HVH-555M is 24.60%. 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 LR7-60HVH-555M?
Longi Solar LR8-66HYD-670M uses Back Contact cells; Longi Solar LR7-60HVH-555M 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 LR7-60HVH-555M?
Longi Solar LR8-66HYD-670M has a 30 years power warranty; Longi Solar LR7-60HVH-555M 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 LR7-60HVH-555M bifacial panels?
Longi Solar LR8-66HYD-670M is bifacial (captures light from both faces); Longi Solar LR7-60HVH-555M is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath.

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.