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66HD650 vs 66HD645 18 of 19 identical Swap Change panels

Tongwei TWMNH-66HD650 vs Tongwei TWMNH-66HD645

Tongwei TWMNH-66HD650
TWMNH-66HD650
650 Wp 24.10 % N-type Bifacial
Open panel page Datasheet PDF
VS
Tongwei TWMNH-66HD645
TWMNH-66HD645
645 Wp 23.90 % N-type Bifacial
Open panel page Datasheet PDF
The verdict

66HD650 leads on the differences that matter

The largest is module efficiency: 0.20 pp more efficient. 18 of 19 comparable parameters are identical.

See the one difference
How alike are they
18 of 19 comparable
parameters are identical
identical differs
01

What actually differs

1 of 19 parameters
Parameter 66HD650 66HD645 Difference
Module efficiency 24.10 % 23.90 % 0.20 pp more efficient
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 (-0.280 %/°C), so a warmer roof scales both curves by the same factor: the totals fall together and neither panel gains on the other.
66HD650
21,809 kWh
66HD645
21,641 kWh
Lifetime gap
168 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 66HD650 66HD645
Standard test conditions 25 °C 100.0% of rated power 650 W 645 W
Cool, bright day 40 °C 95.8% of rated power 623 W 618 W
Typical summer roof 55 °C 91.6% of rated power 595 W 591 W
Hot roof 70 °C 87.4% of rated power 568 W 564 W
03

Full specification

Parameter 66HD650 66HD645 Difference
Power and efficiency
Rated power 650 Wp 645 Wp Effectively the same
Module efficiency 24.10 % 23.90 % +0.20 pp for 66HD650
Power density 240.6 Wp/m² 238.8 Wp/m² Effectively the same
Open-circuit voltage 50.00 V 49.85 V Effectively the same
Voltage at max power 41.65 V 41.51 V Effectively the same
Short-circuit current 16.45 A 16.39 A Effectively the same
Current at max power 15.61 A 15.54 A Effectively the same
Temperature
Temperature coefficient -0.280 %/°C -0.280 %/°C Same
Mechanical
Dimensions 2382x1134x30 mm 2382x1134x30 mm Same
Module area 2.701 m² 2.701 m² Same
Weight 32.2 kg 32.2 kg Same
Weight per kWp 49.5 kg/kWp 49.9 kg/kWp Effectively the same
Warranty and degradation
Product warranty 12 yrs 12 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 132 132 Same
Bifacial Yes Yes Same
04

Against the whole database

14,005 panels
Efficiency
#219 vs #351
66HD650 leads by 132 places
Power density
#233 vs #356
66HD650 leads by 123 places
Heat behaviour
#1,309 vs #1,309
Tied - the same position in the database
Weight
#3,093 vs #3,293
66HD650 leads by 200 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#1,146 vs #1,342
66HD650 leads by 196 places
05

More useful comparisons

Open the full database
Same series, other bin
Tongwei TWMNH-66HD650 vs Tongwei TWMNF-66HD750
7 differences, the largest is rated power
Same series, other bin
Tongwei TWMNH-66HD650 vs Tongwei TWMNF-66HD745
7 differences, the largest is rated power
Same series, other bin
Tongwei TWMNH-66HD650 vs Tongwei TWMNF-66HD740
8 differences, the largest is rated power
Same series, other bin
Tongwei TWMNH-66HD650 vs Tongwei TWMHF-66HD740X
9 differences, the largest is temperature coefficient
Same series, other bin
Tongwei TWMNH-66HD650 vs Tongwei TWMNF-66HD735
9 differences, the largest is rated power
Same series, other bin
Tongwei TWMNH-66HD650 vs Tongwei TWMHF-66HD735X
10 differences, the largest is temperature coefficient
06

Written summary

07

Questions about this pairing

Which panel is better: Tongwei TWMNH-66HD650 or Tongwei TWMNH-66HD645?
According to our database: Tongwei TWMNH-66HD650 has higher module efficiency (24.10% vs 23.90%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Tongwei TWMNH-66HD650 and Tongwei TWMNH-66HD645?
Tongwei TWMNH-66HD650 has a module efficiency of 24.10%, while Tongwei TWMNH-66HD645 is 23.90%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Tongwei TWMNH-66HD650 use vs Tongwei TWMNH-66HD645?
Tongwei TWMNH-66HD650 uses N-type cells; Tongwei TWMNH-66HD645 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 Tongwei TWMNH-66HD650 and Tongwei TWMNH-66HD645?
Tongwei TWMNH-66HD650 has a 30 years power warranty; Tongwei TWMNH-66HD645 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 Tongwei TWMNH-66HD650 and Tongwei TWMNH-66HD645 bifacial panels?
Both Tongwei TWMNH-66HD650 and Tongwei TWMNH-66HD645 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 72 Tongwei 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.