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LR5-72HGD-590M vs LR8-66HYD-670M 4 of 18 identical Swap Change panels

Longi Solar LR5-72HGD-590M vs Longi Solar LR8-66HYD-670M

Longi Solar LR5-72HGD-590M
LR5-72HGD-590M
590 Wp 22.80 % N-type Bifacial
Open panel page Datasheet PDF
VS
Longi Solar LR8-66HYD-670M
LR8-66HYD-670M
670 Wp 24.80 % Back Contact Bifacial Incomplete
Open panel page Datasheet PDF
The verdict

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

The largest is module efficiency: 2.00 pp more efficient. 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 LR5-72HGD-590M LR8-66HYD-670M Difference
Module efficiency 22.80 % 24.80 % 2.00 pp more efficient
Rated power 590 Wp 670 Wp 80 W more power
Power density 228.4 Wp/m² 248.0 Wp/m² 19.6 Wp/m² higher
Temperature coefficient -0.280 %/°C -0.260 %/°C 0.020 %/°C better in heat
Short-circuit current 14.38 A 16.86 A 2.48 A apart
Module area 2.583 m² 2.701 m² 0.118 m² apart
Weight per kWp 53.9 kg/kWp 50.0 kg/kWp 3.9 kg/kWp lighter
Weight 31.8 kg 33.5 kg 1.7 kg lighter
Cell technology N-type Back Contact N-type vs Back Contact
Current at max power 13.59 A 16.19 A 2.60 A apart
Cell count 144 132 12 cells apart
Open-circuit voltage 51.63 V 50.12 V 1.51 V apart
Voltage at max power 43.44 V 41.38 V 2.06 V apart
Dimensions 2278x1134x30 mm 2382x1134x30 mm 2278x1134x30 mm vs 2382x1134x30 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
LR5-72HGD-590M
19,796 kWh
LR8-66HYD-670M
22,480 kWh
Lifetime gap
2,684 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario LR5-72HGD-590M LR8-66HYD-670M
Standard test conditions 25 °C 100.0% of rated power 590 W 670 W
Cool, bright day 40 °C 95.8% of rated power 565 W 644 W
Typical summer roof 55 °C 91.6% of rated power 540 W 618 W
Hot roof 70 °C 87.4% of rated power 516 W 592 W
03

Full specification

Parameter LR5-72HGD-590M LR8-66HYD-670M Difference
Power and efficiency
Rated power 590 Wp 670 Wp +80 W for LR8-66HYD-670M
Module efficiency 22.80 % 24.80 % +2.00 pp for LR8-66HYD-670M
Power density 228.4 Wp/m² 248.0 Wp/m² +19.6 Wp/m² for LR8-66HYD-670M
Open-circuit voltage 51.63 V 50.12 V 1.51 V apart
Voltage at max power 43.44 V 41.38 V 2.06 V apart
Short-circuit current 14.38 A 16.86 A 2.48 A apart
Current at max power 13.59 A 16.19 A 2.60 A apart
Temperature
Temperature coefficient -0.280 %/°C -0.260 %/°C +0.020 %/°C for LR8-66HYD-670M
Mechanical
Dimensions 2278x1134x30 mm 2382x1134x30 mm 2278x1134x30 mm vs 2382x1134x30 mm
Module area 2.583 m² 2.701 m² 0.118 m² apart
Weight 31.8 kg 33.5 kg -1.7 kg for LR5-72HGD-590M
Weight per kWp 53.9 kg/kWp 50.0 kg/kWp -3.9 kg/kWp for LR8-66HYD-670M
Warranty and degradation
Product warranty 12 yrs 12 yrs Same
Performance warranty 30 yrs 30 yrs Same
Annual degradation 0.40 %/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
#2,714 vs #12
LR8-66HYD-670M leads by 2,702 places
Power density
#2,598 vs #14
LR8-66HYD-670M leads by 2,584 places
Heat behaviour
#1,309 vs #511
LR8-66HYD-670M leads by 798 places
Weight
#8,021 vs #3,317
LR8-66HYD-670M leads by 4,704 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#3,801 vs #490
LR8-66HYD-670M leads by 3,311 places
05

More useful comparisons

Open the full database
Same series, other bin
Longi Solar LR5-72HGD-590M vs Longi Solar LR7-72HVHF-670M
15 differences, the largest is module efficiency
Same series, other bin
Longi Solar LR5-72HGD-590M vs Longi Solar LR7-72HVH-670M
15 differences, the largest is module efficiency
Same series, other bin
Longi Solar LR5-72HGD-590M vs Longi Solar LR7-72HVHF-665M
15 differences, the largest is module efficiency
Same series, other bin
Longi Solar LR5-72HGD-590M vs Longi Solar LR7-72HVDF-665M
14 differences, the largest is module efficiency
Same series, other bin
Longi Solar LR5-72HGD-590M vs Longi Solar LR7-72HVD-665M
14 differences, the largest is module efficiency
Same series, other bin
Longi Solar LR5-72HGD-590M vs Longi Solar LR7-72HVH-665M
15 differences, the largest is module efficiency
06

Written summary

07

Questions about this pairing

Which panel is better: Longi Solar LR5-72HGD-590M or Longi Solar LR8-66HYD-670M?
According to our database: Longi Solar LR8-66HYD-670M has higher module efficiency (24.80% vs 22.80%); Longi Solar LR8-66HYD-670M tolerates heat better (temp coeff -0.260%/°C vs -0.280%/°C). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Longi Solar LR5-72HGD-590M and Longi Solar LR8-66HYD-670M?
Longi Solar LR5-72HGD-590M has a module efficiency of 22.80%, 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 LR5-72HGD-590M use vs Longi Solar LR8-66HYD-670M?
Longi Solar LR5-72HGD-590M 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 LR5-72HGD-590M and Longi Solar LR8-66HYD-670M?
Longi Solar LR5-72HGD-590M 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 LR5-72HGD-590M and Longi Solar LR8-66HYD-670M bifacial panels?
Both Longi Solar LR5-72HGD-590M 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.

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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.