Gokin GK-4-78HGBD-770M vs Gokin GK-4-78HGBD-775M
VS
The verdict
Identical on every published parameter
All 19 comparable parameters agree. Two records this alike are usually one panel sold under two names, or two bins of the same production line - decide on price and on who you would rather buy from.
How alike are they
19
of 19 comparable
parameters are identical
parameters are identical
identical
differs
01
0 of 19 parameters
What actually differs
Every comparable parameter agrees. The full specification is below.
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
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.
770M
26,036 kWh
775M
26,205 kWh
Lifetime gap
169 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario
770M
775M
Standard test conditions
25 °C
100.0% of rated power
770 W
775 W
Cool, bright day
40 °C
96.1% of rated power
740 W
745 W
Typical summer roof
55 °C
92.2% of rated power
710 W
715 W
Hot roof
70 °C
88.3% of rated power
680 W
684 W
03
Full specification
Parameter
770M
775M
Difference
Power and efficiency
Rated power
770 Wp
775 Wp
Effectively the same
Module efficiency
24.00 %
24.10 %
Effectively the same
Power density
239.7 Wp/m²
241.3 Wp/m²
Effectively the same
Open-circuit voltage
58.72 V
58.82 V
Effectively the same
Voltage at max power
48.77 V
48.87 V
Effectively the same
Short-circuit current
16.64 A
16.71 A
Effectively the same
Current at max power
15.79 A
15.86 A
Effectively the same
Temperature
Temperature coefficient
-0.260 %/°C
-0.260 %/°C
Same
Mechanical
Dimensions
2465x1303x33 mm
2465x1303x33 mm
Same
Module area
3.212 m²
3.212 m²
Same
Weight
38.7 kg
38.7 kg
Same
Weight per kWp
50.3 kg/kWp
49.9 kg/kWp
Effectively the same
Warranty and degradation
Product warranty
15 yrs
15 yrs
Same
Performance warranty
30 yrs
30 yrs
Same
Annual degradation
0.35 %/yr
0.35 %/yr
Same
Technology
Cell technology
Back Contact
Back Contact
Same
Cell type
Monocrystalline
Monocrystalline
Same
Cell count
156
156
Same
Bifacial
Yes
Yes
Same
04
14,005 panels
Against the whole database
Efficiency
#303
vs
#219
775M leads by 84 places
Power density
#347
vs
#227
775M leads by 120 places
Heat behaviour
#511
vs
#511
Tied - the same position in the database
Weight
#3,695
vs
#3,297
775M leads by 398 places
Warranty
#21
vs
#21
Tied - the same position in the database
Overall
#39
vs
#29
775M leads by 10 places
05
Open the full database
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06
Written summary
Checking cache...
07
Questions about this pairing
Which panel is better: Gokin GK-4-78HGBD-770M or Gokin GK-4-78HGBD-775M?
According to our database: Gokin GK-4-78HGBD-775M has higher module efficiency (24.10% vs 24.00%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Gokin GK-4-78HGBD-770M and Gokin GK-4-78HGBD-775M?
Gokin GK-4-78HGBD-770M has a module efficiency of 24.00%, while Gokin GK-4-78HGBD-775M is 24.10%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Gokin GK-4-78HGBD-770M use vs Gokin GK-4-78HGBD-775M?
Gokin GK-4-78HGBD-770M uses Back Contact cells; Gokin GK-4-78HGBD-775M 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 Gokin GK-4-78HGBD-770M and Gokin GK-4-78HGBD-775M?
Gokin GK-4-78HGBD-770M has a 30 years power warranty; Gokin GK-4-78HGBD-775M 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 Gokin GK-4-78HGBD-770M and Gokin GK-4-78HGBD-775M bifacial panels?
Both Gokin GK-4-78HGBD-770M and Gokin GK-4-78HGBD-775M 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.