Skip to main content
A660-GRH66Dw vs A645-GRH66Dw 16 of 19 identical Swap Change panels

AIKO AIKO-A660-GRH66Dw vs AIKO AIKO-A645-GRH66Dw

AIKO AIKO-A660-GRH66Dw
AIKO-A660-GRH66Dw
660 Wp 24.40 % Back Contact Bifacial
Open panel page Datasheet PDF
VS
AIKO AIKO-A645-GRH66Dw
AIKO-A645-GRH66Dw
645 Wp 23.90 % Back Contact Bifacial
Open panel page Datasheet PDF
The verdict

A660-GRH66Dw leads on the differences that matter

The largest is module efficiency: 0.50 pp more efficient. 16 of 19 comparable parameters are identical.

See all 3 differences
How alike are they
16 of 19 comparable
parameters are identical
identical differs
01

What actually differs

3 of 19 parameters
Parameter A660-GRH66Dw A645-GRH66Dw Difference
Module efficiency 24.40 % 23.90 % 0.50 pp more efficient
Power density 244.3 Wp/m² 238.8 Wp/m² 5.6 Wp/m² higher
Rated power 660 Wp 645 Wp 15 W more power
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.
A660-GRH66Dw
22,317 kWh
A645-GRH66Dw
21,809 kWh
Lifetime gap
508 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario A660-GRH66Dw A645-GRH66Dw
Standard test conditions 25 °C 100.0% of rated power 660 W 645 W
Cool, bright day 40 °C 96.1% of rated power 634 W 620 W
Typical summer roof 55 °C 92.2% of rated power 609 W 595 W
Hot roof 70 °C 88.3% of rated power 583 W 570 W
03

Full specification

Parameter A660-GRH66Dw A645-GRH66Dw Difference
Power and efficiency
Rated power 660 Wp 645 Wp +15 W for A660-GRH66Dw
Module efficiency 24.40 % 23.90 % +0.50 pp for A660-GRH66Dw
Power density 244.3 Wp/m² 238.8 Wp/m² +5.6 Wp/m² for A660-GRH66Dw
Open-circuit voltage 49.50 V 49.20 V Effectively the same
Voltage at max power 42.20 V 41.90 V Effectively the same
Short-circuit current 16.76 A 16.55 A Effectively the same
Current at max power 15.65 A 15.40 A Effectively the same
Temperature
Temperature coefficient -0.260 %/°C -0.260 %/°C Same
Mechanical
Dimensions 2382x1134x30 mm 2382x1134x30 mm Same
Module area 2.701 m² 2.701 m² Same
Weight 32.5 kg 32.5 kg Same
Weight per kWp 49.2 kg/kWp 50.4 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 132 132 Same
Bifacial Yes Yes Same
04

Against the whole database

14,005 panels
Efficiency
#99 vs #351
A660-GRH66Dw leads by 252 places
Power density
#88 vs #356
A660-GRH66Dw leads by 268 places
Heat behaviour
#511 vs #511
Tied - the same position in the database
Weight
#2,811 vs #3,767
A660-GRH66Dw leads by 956 places
Warranty
#21 vs #21
Tied - the same position in the database
Overall
#569 vs #1,073
A660-GRH66Dw leads by 504 places
05

More useful comparisons

Open the full database
Same series, other bin
AIKO AIKO-A660-GRH66Dw vs AIKO AIKO-G660-MCH72Dw
6 differences, the largest is open-circuit voltage
Same series, other bin
AIKO AIKO-A660-GRH66Dw vs AIKO AIKO-A655-GRH66Dw
One difference: module efficiency
Same series, other bin
AIKO AIKO-A660-GRH66Dw vs AIKO AIKO-A650-GRH66Dw
3 differences, the largest is module efficiency
Same series, other bin
AIKO AIKO-A660-GRH66Dw vs AIKO AIKO-A640-GRH66Dw
3 differences, the largest is module efficiency
Same manufacturer
AIKO AIKO-A660-GRH66Dw vs AIKO AIKO-A805-GRH78Dw
10 differences, the largest is module efficiency
Same manufacturer
AIKO AIKO-A660-GRH66Dw vs AIKO AIKO-A800-GRH78Dw
10 differences, the largest is rated power
06

Written summary

07

Questions about this pairing

Which panel is better: AIKO AIKO-A660-GRH66Dw or AIKO AIKO-A645-GRH66Dw?
According to our database: AIKO AIKO-A660-GRH66Dw has higher module efficiency (24.40% vs 23.90%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of AIKO AIKO-A660-GRH66Dw and AIKO AIKO-A645-GRH66Dw?
AIKO AIKO-A660-GRH66Dw has a module efficiency of 24.40%, while AIKO AIKO-A645-GRH66Dw is 23.90%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does AIKO AIKO-A660-GRH66Dw use vs AIKO AIKO-A645-GRH66Dw?
AIKO AIKO-A660-GRH66Dw uses Back Contact cells; AIKO AIKO-A645-GRH66Dw 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 AIKO AIKO-A660-GRH66Dw and AIKO AIKO-A645-GRH66Dw?
AIKO AIKO-A660-GRH66Dw has a 30 years power warranty; AIKO AIKO-A645-GRH66Dw 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 AIKO AIKO-A660-GRH66Dw and AIKO AIKO-A645-GRH66Dw bifacial panels?
Both AIKO AIKO-A660-GRH66Dw and AIKO AIKO-A645-GRH66Dw 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 174 AIKO 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.