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BGT78(640) vs BBT78(635) 15 of 19 identical Swap Change panels

Sunova TS-BGT78(640) vs Sunova TS-BBT78(635)

TS-BGT78(640)
640 Wp 22.90 % N-type Bifacial
Open panel page Datasheet PDF
VS
TS-BBT78(635)
635 Wp 22.70 % N-type Bifacial
Open panel page Datasheet PDF
The verdict

BBT78(635) leads on the differences that matter

The largest is weight: 5.0 kg lighter. 15 of 19 comparable parameters are identical.

See all 4 differences
How alike are they
15 of 19 comparable
parameters are identical
identical differs
01

What actually differs

4 of 19 parameters
Parameter BGT78(640) BBT78(635) Difference
Weight 34.0 kg 29.0 kg 5.0 kg lighter
Weight per kWp 53.1 kg/kWp 45.7 kg/kWp 7.5 kg/kWp lighter
Module efficiency 22.90 % 22.70 % 0.20 pp more efficient
Dimensions 2464x1134x35 mm 2465x1134x35 mm 2464x1134x35 mm vs 2465x1134x35 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 (-0.290 %/°C), so a warmer roof scales both curves by the same factor: the totals fall together and neither panel gains on the other.
BGT78(640)
21,473 kWh
BBT78(635)
21,306 kWh
Lifetime gap
167 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario BGT78(640) BBT78(635)
Standard test conditions 25 °C 100.0% of rated power 640 W 635 W
Cool, bright day 40 °C 95.7% of rated power 612 W 607 W
Typical summer roof 55 °C 91.3% of rated power 584 W 580 W
Hot roof 70 °C 87.0% of rated power 556 W 552 W
03

Full specification

Parameter BGT78(640) BBT78(635) Difference
Power and efficiency
Rated power 640 Wp 635 Wp Effectively the same
Module efficiency 22.90 % 22.70 % +0.20 pp for BGT78(640)
Power density 229.0 Wp/m² 227.2 Wp/m² Effectively the same
Open-circuit voltage 56.75 V 56.56 V Effectively the same
Voltage at max power 48.18 V 47.99 V Effectively the same
Short-circuit current 13.94 A 13.89 A Effectively the same
Current at max power 13.28 A 13.23 A Effectively the same
Temperature
Temperature coefficient -0.290 %/°C -0.290 %/°C Same
Mechanical
Dimensions 2464x1134x35 mm 2465x1134x35 mm 2464x1134x35 mm vs 2465x1134x35 mm
Module area 2.794 m² 2.795 m² Effectively the same
Weight 34.0 kg 29.0 kg -5.0 kg for BBT78(635)
Weight per kWp 53.1 kg/kWp 45.7 kg/kWp -7.5 kg/kWp for BBT78(635)
Warranty and degradation
Product warranty 15 yrs 15 yrs Same
Performance warranty 30 yrs 30 yrs Same
Annual degradation 0.40 %/yr 0.40 %/yr Same
Technology
Cell technology N-type N-type Same
Cell type Monocrystalline Monocrystalline Same
Cell count 156 156 Same
Bifacial Yes Yes Same
04

Against the whole database

14,005 panels
Efficiency
#2,359 vs #3,307
BGT78(640) leads by 948 places
Power density
#2,380 vs #3,252
BGT78(640) leads by 872 places
Heat behaviour
#2,165 vs #2,165
Tied - the same position in the database
Weight
#6,913 vs #833
BBT78(635) leads by 6,080 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#1,695 vs #1,869
BGT78(640) leads by 174 places
05

More useful comparisons

Open the full database
Same series, other bin
Sunova TS-BGT78(640) vs Sunova TS-BBT78(640)
3 differences, the largest is weight
Same series, other bin
Sunova TS-BGT78(640) vs Sunova TS-BGT78(635)
One difference: module efficiency
Same series, other bin
Sunova TS-BGT78(640) vs Sunova TS-BGT78(630)
3 differences, the largest is module efficiency
Same series, other bin
Sunova TS-BGT78(640) vs Sunova TS-BBT78(630)
6 differences, the largest is weight
Same series, other bin
Sunova TS-BGT78(640) vs Sunova TS-BBT78(625)
6 differences, the largest is module efficiency
Same series, other bin
Sunova TS-BGT78(640) vs Sunova TS-BGT78(625)
3 differences, the largest is module efficiency
06

Written summary

07

Questions about this pairing

Which panel is better: Sunova TS-BGT78(640) or Sunova TS-BBT78(635)?
According to our database: Sunova TS-BGT78(640) has higher module efficiency (22.90% vs 22.70%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Sunova TS-BGT78(640) and Sunova TS-BBT78(635)?
Sunova TS-BGT78(640) has a module efficiency of 22.90%, while Sunova TS-BBT78(635) is 22.70%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Sunova TS-BGT78(640) use vs Sunova TS-BBT78(635)?
Sunova TS-BGT78(640) uses N-type cells; Sunova TS-BBT78(635) uses N-type. 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 Sunova TS-BGT78(640) and Sunova TS-BBT78(635)?
Sunova TS-BGT78(640) has a 30 years power warranty; Sunova TS-BBT78(635) 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 Sunova TS-BGT78(640) and Sunova TS-BBT78(635) bifacial panels?
Both Sunova TS-BGT78(640) and Sunova TS-BBT78(635) 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.

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.