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GK-4-78HGBD-775M vs GSD8K66H-735WT 6 of 19 identical Swap Change panels

Gokin GK-4-78HGBD-775M vs Sharp GSD8K66H-735WT

Gokin GK-4-78HGBD-775M
Gokin
GK-4-78HGBD-775M
775 Wp 24.10 % Back Contact Bifacial
VS
Sharp GSD8K66H-735WT
Sharp
GSD8K66H-735WT
735 Wp 23.66 % HJT Bifacial
The verdict

GK-4-78HGBD-775M leads on the differences that matter

The largest is rated power: 40 W more power. 6 of 19 comparable parameters are identical.

See all 13 differences
How alike are they
6 of 19 comparable
parameters are identical
identical differs
01

What actually differs

13 of 19 parameters
Parameter GK-4-78HGBD-775M GSD8K66H-735WT Difference
Rated power 775 Wp 735 Wp 40 W more power
Product warranty 15 yrs 25 yrs 10 yrs longer
Module efficiency 24.10 % 23.66 % 0.44 pp more efficient
Open-circuit voltage 58.82 V 51.50 V 7.32 V apart
Module area 3.212 m² 3.106 m² 0.106 m² apart
Power density 241.3 Wp/m² 236.6 Wp/m² 4.7 Wp/m² higher
Cell technology Back Contact HJT Back Contact vs HJT
Weight per kWp 49.9 kg/kWp 53.1 kg/kWp 3.1 kg/kWp lighter
Short-circuit current 16.71 A 17.72 A 1.01 A apart
Voltage at max power 48.87 V 43.60 V 5.27 V apart
Cell count 156 132 24 cells apart
Current at max power 15.86 A 16.87 A 1.01 A apart
Dimensions 2465x1303x33 mm 2384x1303x35 mm 2465x1303x33 mm vs 2384x1303x35 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
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.
GK-4-78HGBD-775M
26,205 kWh
GSD8K66H-735WT
24,853 kWh
Lifetime gap
1,352 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario GK-4-78HGBD-775M GSD8K66H-735WT
Standard test conditions 25 °C 100.0% of rated power 775 W 735 W
Cool, bright day 40 °C 96.1% of rated power 745 W 706 W
Typical summer roof 55 °C 92.2% of rated power 715 W 678 W
Hot roof 70 °C 88.3% of rated power 684 W 649 W
03

Full specification

Parameter GK-4-78HGBD-775M GSD8K66H-735WT Difference
Power and efficiency
Rated power 775 Wp 735 Wp +40 W for GK-4-78HGBD-775M
Module efficiency 24.10 % 23.66 % +0.44 pp for GK-4-78HGBD-775M
Power density 241.3 Wp/m² 236.6 Wp/m² +4.7 Wp/m² for GK-4-78HGBD-775M
Open-circuit voltage 58.82 V 51.50 V 7.32 V apart
Voltage at max power 48.87 V 43.60 V 5.27 V apart
Short-circuit current 16.71 A 17.72 A 1.01 A apart
Current at max power 15.86 A 16.87 A 1.01 A apart
Temperature
Temperature coefficient -0.260 %/°C -0.260 %/°C Same
Mechanical
Dimensions 2465x1303x33 mm 2384x1303x35 mm 2465x1303x33 mm vs 2384x1303x35 mm
Module area 3.212 m² 3.106 m² 0.106 m² apart
Weight 38.7 kg 39.0 kg Effectively the same
Weight per kWp 49.9 kg/kWp 53.1 kg/kWp -3.1 kg/kWp for GK-4-78HGBD-775M
Warranty and degradation
Product warranty 15 yrs 25 yrs +10 yrs for GSD8K66H-735WT
Performance warranty 30 yrs 30 yrs Same
Annual degradation 0.35 %/yr 0.35 %/yr Same
Technology
Cell technology Back Contact HJT Back Contact vs HJT
Cell type Monocrystalline Monocrystalline Same
Cell count 156 132 24 cells apart
Bifacial Yes Yes Same
04

Against the whole database

14,005 panels
Efficiency
#219 vs #602
GK-4-78HGBD-775M leads by 383 places
Power density
#227 vs #582
GK-4-78HGBD-775M leads by 355 places
Heat behaviour
#511 vs #511
Tied - the same position in the database
Weight
#3,297 vs #6,818
GK-4-78HGBD-775M leads by 3,521 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#29 vs #21
GSD8K66H-735WT leads by 8 places
05

More useful comparisons

Open the full database
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Sharp GSD8K66H-735WT vs Sharp GSD8K66H-740WT
The same specification on paper
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Sharp GSD8K66H-735WT vs Sharp GSD8K66H-730WT
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06

Written summary

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07

Questions about this pairing

Which panel is better: Gokin GK-4-78HGBD-775M or Sharp GSD8K66H-735WT?
According to our database: Gokin GK-4-78HGBD-775M has higher module efficiency (24.10% vs 23.66%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Gokin GK-4-78HGBD-775M and Sharp GSD8K66H-735WT?
Gokin GK-4-78HGBD-775M has a module efficiency of 24.10%, while Sharp GSD8K66H-735WT is 23.66%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Gokin GK-4-78HGBD-775M use vs Sharp GSD8K66H-735WT?
Gokin GK-4-78HGBD-775M uses Back Contact cells; Sharp GSD8K66H-735WT uses HJT. 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-775M and Sharp GSD8K66H-735WT?
Gokin GK-4-78HGBD-775M has a 30 years power warranty; Sharp GSD8K66H-735WT 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-775M and Sharp GSD8K66H-735WT bifacial panels?
Both Gokin GK-4-78HGBD-775M and Sharp GSD8K66H-735WT 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.
Compare Gokin and Sharp as manufacturers Portfolio, efficiency, cell technologies and warranty terms

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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.