Longi Solar LR5-66HPH-500M vs Longi Solar LR5-66HPH-515M
VS
The verdict
515M leads on the differences that matter
The largest is module efficiency: 0.40 pp more efficient. 12 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it.
See all 6 differencesHow alike are they
12
of 18 comparable
parameters are identical
parameters are identical
identical
differs
not published
01
6 of 18 parameters
What actually differs
Parameter
500M
515M
Difference
Module efficiency
21.30 %
21.70 %
0.40 pp more efficient
Rated power
500 Wp
515 Wp
15 W more power
Power density
212.9 Wp/m²
217.0 Wp/m²
4.1 Wp/m² higher
Temperature coefficient
-0.350 %/°C
-0.340 %/°C
0.010 %/°C better in heat
Module area
2.349 m²
2.373 m²
0.025 m² apart
Dimensions
2073x1133x35 mm
2093x1134x35 mm
2073x1133x35 mm vs 2093x1134x35 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
500M
16,205 kWh
515M
16,691 kWh
Lifetime gap
486 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
500M
515M
Standard test conditions
25 °C
100.0% of rated power
500 W
515 W
Cool, bright day
40 °C
94.8% of rated power
474 W
489 W
Typical summer roof
55 °C
89.5% of rated power
448 W
462 W
Hot roof
70 °C
84.2% of rated power
421 W
436 W
03
Full specification
Parameter
500M
515M
Difference
Power and efficiency
Rated power
500 Wp
515 Wp
+15 W for 515M
Module efficiency
21.30 %
21.70 %
+0.40 pp for 515M
Power density
212.9 Wp/m²
217.0 Wp/m²
+4.1 Wp/m² for 515M
Open-circuit voltage
45.55 V
46.00 V
Effectively the same
Voltage at max power
38.38 V
38.83 V
Effectively the same
Short-circuit current
13.90 A
14.13 A
Effectively the same
Current at max power
13.03 A
13.27 A
Effectively the same
Temperature
Temperature coefficient
-0.350 %/°C
-0.340 %/°C
+0.010 %/°C for 515M
Mechanical
Dimensions
2073x1133x35 mm
2093x1134x35 mm
2073x1133x35 mm vs 2093x1134x35 mm
Module area
2.349 m²
2.373 m²
0.025 m² apart
Weight
25.1 kg
25.3 kg
Effectively the same
Weight per kWp
50.2 kg/kWp
49.1 kg/kWp
Effectively the same
Warranty and degradation
Product warranty
12 yrs
12 yrs
Same
Performance warranty
25 yrs
25 yrs
Same
Annual degradation
0.55 %/yr
0.55 %/yr
Same
Technology
Cell technology
PERC
-
Not published by Longi Solar
Cell type
Monocrystalline
Monocrystalline
Same
Cell count
132
132
Same
Bifacial
No
No
Same
04
14,005 panels
Against the whole database
Efficiency
#8,519
vs
#7,421
515M leads by 1,098 places
Power density
#8,599
vs
#7,426
515M leads by 1,173 places
Heat behaviour
#10,419
vs
#8,778
515M leads by 1,641 places
Weight
#3,664
vs
#2,764
515M leads by 900 places
Warranty
#9,798
vs
#9,798
Tied - the same position in the database
Overall
#9,679
vs
#8,762
515M leads by 917 places
05
Open the full database
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Longi Solar LR5-66HPH-500M vs Longi Solar LR5-72HPH-555M
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06
Written summary
Checking cache...
07
Questions about this pairing
Which panel is better: Longi Solar LR5-66HPH-500M or Longi Solar LR5-66HPH-515M?
According to our database: Longi Solar LR5-66HPH-515M has higher module efficiency (21.70% vs 21.30%); Longi Solar LR5-66HPH-515M tolerates heat better (temp coeff -0.340%/°C vs -0.350%/°C). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Longi Solar LR5-66HPH-500M and Longi Solar LR5-66HPH-515M?
Longi Solar LR5-66HPH-500M has a module efficiency of 21.30%, while Longi Solar LR5-66HPH-515M is 21.70%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Longi Solar LR5-66HPH-500M use vs Longi Solar LR5-66HPH-515M?
Longi Solar LR5-66HPH-500M uses PERC cells; Longi Solar LR5-66HPH-515M uses Monocrystalline. 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 LR5-66HPH-500M and Longi Solar LR5-66HPH-515M?
Longi Solar LR5-66HPH-500M has a 25 years power warranty; Longi Solar LR5-66HPH-515M has a 25 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.
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.

