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LR5-72HBD-540M vs LR8-66HVD-655M 5 of 18 identical Swap Change panels

Longi Solar LR5-72HBD-540M vs Longi Solar LR8-66HVD-655M

Longi Solar LR5-72HBD-540M
LR5-72HBD-540M
540 Wp 20.90 % Bifacial
Open panel page Datasheet PDF
VS
Longi Solar LR8-66HVD-655M
LR8-66HVD-655M
655 Wp 24.25 % Back Contact Bifacial
Open panel page Datasheet PDF
The verdict

LR8-66HVD-655M leads on the differences that matter

The largest is module efficiency: 3.35 pp more efficient. 5 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it.

See all 13 differences
How alike are they
5 of 18 comparable
parameters are identical
identical differs not published
01

What actually differs

13 of 18 parameters
Parameter LR5-72HBD-540M LR8-66HVD-655M Difference
Module efficiency 20.90 % 24.25 % 3.35 pp more efficient
Temperature coefficient -0.340 %/°C -0.260 %/°C 0.080 %/°C better in heat
Rated power 540 Wp 655 Wp 115 W more power
Power density 209.0 Wp/m² 242.5 Wp/m² 33.4 Wp/m² higher
Weight per kWp 58.9 kg/kWp 51.1 kg/kWp 7.7 kg/kWp lighter
Product warranty 12 yrs 15 yrs 3 yrs longer
Annual degradation 0.45 %/yr 0.35 %/yr 0.10 %/yr slower
Short-circuit current 13.85 A 16.62 A 2.77 A apart
Module area 2.583 m² 2.701 m² 0.118 m² apart
Weight 31.8 kg 33.5 kg 1.7 kg lighter
Current at max power 12.97 A 15.94 A 2.97 A apart
Cell count 144 132 12 cells apart
Dimensions 2278x1134x30 mm 2382x1134x30 mm 2278x1134x30 mm vs 2382x1134x30 mm
02

What it means on a roof

Thirty years of production
Each panel's own declared degradation curve, at 1,200 kWh/kWp a year
LR5-72HBD-540M
17,783 kWh
LR8-66HVD-655M
22,148 kWh
Lifetime gap
4,365 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario LR5-72HBD-540M LR8-66HVD-655M
Standard test conditions 25 °C 100.0% of rated power 540 W 655 W
Cool, bright day 40 °C 94.9% of rated power 512 W 629 W
Typical summer roof 55 °C 89.8% of rated power 485 W 604 W
Hot roof 70 °C 84.7% of rated power 457 W 578 W
03

Full specification

Parameter LR5-72HBD-540M LR8-66HVD-655M Difference
Power and efficiency
Rated power 540 Wp 655 Wp +115 W for LR8-66HVD-655M
Module efficiency 20.90 % 24.25 % +3.35 pp for LR8-66HVD-655M
Power density 209.0 Wp/m² 242.5 Wp/m² +33.4 Wp/m² for LR8-66HVD-655M
Open-circuit voltage 49.50 V 49.82 V Effectively the same
Voltage at max power 41.65 V 41.08 V Effectively the same
Short-circuit current 13.85 A 16.62 A 2.77 A apart
Current at max power 12.97 A 15.94 A 2.97 A apart
Temperature
Temperature coefficient -0.340 %/°C -0.260 %/°C +0.080 %/°C for LR8-66HVD-655M
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 LR5-72HBD-540M
Weight per kWp 58.9 kg/kWp 51.1 kg/kWp -7.7 kg/kWp for LR8-66HVD-655M
Warranty and degradation
Product warranty 12 yrs 15 yrs +3 yrs for LR8-66HVD-655M
Performance warranty 30 yrs 30 yrs Same
Annual degradation 0.45 %/yr 0.35 %/yr -0.10 %/yr for LR8-66HVD-655M
Technology
Cell technology - Back Contact Not published by Longi Solar
Cell type Monocrystalline Monocrystalline Same
Cell count 144 132 12 cells apart
Bifacial Yes Yes Same
04

Against the whole database

14,129 panels
Efficiency
#10,148 vs #190
LR8-66HVD-655M leads by 9,958 places
Power density
#10,176 vs #192
LR8-66HVD-655M leads by 9,984 places
Heat behaviour
#8,846 vs #515
LR8-66HVD-655M leads by 8,331 places
Weight
#12,026 vs #4,527
LR8-66HVD-655M leads by 7,499 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#7,953 vs #731
LR8-66HVD-655M leads by 7,222 places
05

More useful comparisons

Open the full database
Same series, other bin
Longi Solar LR5-72HBD-540M vs Longi Solar LR7-72HVDF-655M
14 differences, the largest is module efficiency
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Longi Solar LR5-72HBD-540M vs Longi Solar LR7-72HVHF-655M
15 differences, the largest is module efficiency
Same series, other bin
Longi Solar LR5-72HBD-540M vs Longi Solar LR7-72HVD-655M
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Same series, other bin
Longi Solar LR5-72HBD-540M vs Longi Solar LR8-66HYD-655M
12 differences, the largest is module efficiency
Same series, other bin
Longi Solar LR5-72HBD-540M vs Longi Solar LR7-72HYD-655M
13 differences, the largest is module efficiency
Same series, other bin
Longi Solar LR5-72HBD-540M vs Longi Solar LR7-72HVH-655M
15 differences, the largest is module efficiency
06

Written summary

07

Questions about this pairing

Which panel is better: Longi Solar LR5-72HBD-540M or Longi Solar LR8-66HVD-655M?
According to our database: Longi Solar LR8-66HVD-655M has higher module efficiency (24.25% vs 20.90%); Longi Solar LR8-66HVD-655M tolerates heat better (temp coeff -0.260%/°C vs -0.340%/°C). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Longi Solar LR5-72HBD-540M and Longi Solar LR8-66HVD-655M?
Longi Solar LR5-72HBD-540M has a module efficiency of 20.90%, while Longi Solar LR8-66HVD-655M is 24.25%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Longi Solar LR5-72HBD-540M use vs Longi Solar LR8-66HVD-655M?
Longi Solar LR5-72HBD-540M uses Monocrystalline cells; Longi Solar LR8-66HVD-655M 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 LR5-72HBD-540M and Longi Solar LR8-66HVD-655M?
Longi Solar LR5-72HBD-540M has a 30 years power warranty; Longi Solar LR8-66HVD-655M 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 LR5-72HBD-540M and Longi Solar LR8-66HVD-655M bifacial panels?
Both Longi Solar LR5-72HBD-540M and Longi Solar LR8-66HVD-655M 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 157 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.