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WSMD-660 vs WSMDi-405 9 of 19 identical Swap Change panels

Waaree WSMD-660 vs Waaree WSMDi-405

Waaree WSMD-660
WSMD-660
660 Wp 21.13 % PERC
Open panel page Datasheet PDF
VS
Waaree WSMDi-405
WSMDi-405
405 Wp 20.28 % PERC
Open panel page Datasheet PDF
The verdict

WSMD-660 leads on the differences that matter

The largest is module efficiency: 0.85 pp more efficient. 9 of 19 comparable parameters are identical.

See all 10 differences
How alike are they
9 of 19 comparable
parameters are identical
identical differs
01

What actually differs

10 of 19 parameters
Parameter WSMD-660 WSMDi-405 Difference
Module efficiency 21.13 % 20.28 % 0.85 pp more efficient
Rated power 660 Wp 405 Wp 255 W more power
Temperature coefficient -0.340 %/°C -0.365 %/°C 0.025 %/°C better in heat
Weight 34.5 kg 22.0 kg 12.5 kg lighter
Power density 211.2 Wp/m² 202.8 Wp/m² 8.4 Wp/m² higher
Short-circuit current 17.98 A 11.40 A 6.58 A apart
Module area 3.125 m² 1.997 m² 1.128 m² apart
Current at max power 17.35 A 10.61 A 6.74 A apart
Weight per kWp 52.3 kg/kWp 54.3 kg/kWp 2.0 kg/kWp lighter
Dimensions 2400x1302x35 mm 1924x1038x35 mm 2400x1302x35 mm vs 1924x1038x35 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
WSMD-660
21,390 kWh
WSMDi-405
13,126 kWh
Lifetime gap
8,264 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario WSMD-660 WSMDi-405
Standard test conditions 25 °C 100.0% of rated power 660 W 405 W
Cool, bright day 40 °C 94.5% of rated power 626 W 383 W
Typical summer roof 55 °C 89.0% of rated power 593 W 361 W
Hot roof 70 °C 83.6% of rated power 559 W 338 W
03

Full specification

Parameter WSMD-660 WSMDi-405 Difference
Power and efficiency
Rated power 660 Wp 405 Wp +255 W for WSMD-660
Module efficiency 21.13 % 20.28 % +0.85 pp for WSMD-660
Power density 211.2 Wp/m² 202.8 Wp/m² +8.4 Wp/m² for WSMD-660
Open-circuit voltage 46.40 V 45.44 V Effectively the same
Voltage at max power 38.06 V 38.22 V Effectively the same
Short-circuit current 17.98 A 11.40 A 6.58 A apart
Current at max power 17.35 A 10.61 A 6.74 A apart
Temperature
Temperature coefficient -0.340 %/°C -0.365 %/°C +0.025 %/°C for WSMD-660
Mechanical
Dimensions 2400x1302x35 mm 1924x1038x35 mm 2400x1302x35 mm vs 1924x1038x35 mm
Module area 3.125 m² 1.997 m² 1.128 m² apart
Weight 34.5 kg 22.0 kg -12.5 kg for WSMDi-405
Weight per kWp 52.3 kg/kWp 54.3 kg/kWp -2.0 kg/kWp for WSMD-660
Warranty and degradation
Product warranty 12 yrs 12 yrs Same
Performance warranty 27 yrs 27 yrs Same
Annual degradation 0.55 %/yr 0.55 %/yr Same
Technology
Cell technology PERC PERC Same
Cell type Monocrystalline Monocrystalline Same
Cell count 132 132 Same
Bifacial No No Same
04

Against the whole database

14,005 panels
Efficiency
#9,239 vs #11,853
WSMD-660 leads by 2,614 places
Power density
#9,251 vs #11,821
WSMD-660 leads by 2,570 places
Heat behaviour
#8,778 vs #13,045
WSMD-660 leads by 4,267 places
Weight
#5,732 vs #8,586
WSMD-660 leads by 2,854 places
Warranty
#9,667 vs #9,667
Tied - the same position in the database
Overall
#3,874 vs #11,980
WSMD-660 leads by 8,106 places
05

More useful comparisons

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Waaree WSMD-660 vs Waaree WSMD-650
3 differences, the largest is module efficiency
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Waaree WSMD-660 vs Waaree WSMD-645
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Waaree WSMD-660 vs Waaree WSMD-545
10 differences, the largest is rated power
Same series, other bin
Waaree WSMD-660 vs Waaree WSMD-540
10 differences, the largest is rated power
06

Written summary

07

Questions about this pairing

Which panel is better: Waaree WSMD-660 or Waaree WSMDi-405?
According to our database: Waaree WSMD-660 has higher module efficiency (21.13% vs 20.28%); Waaree WSMD-660 tolerates heat better (temp coeff -0.340%/°C vs -0.365%/°C). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Waaree WSMD-660 and Waaree WSMDi-405?
Waaree WSMD-660 has a module efficiency of 21.13%, while Waaree WSMDi-405 is 20.28%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Waaree WSMD-660 use vs Waaree WSMDi-405?
Waaree WSMD-660 uses PERC cells; Waaree WSMDi-405 uses PERC. 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 Waaree WSMD-660 and Waaree WSMDi-405?
Waaree WSMD-660 has a 27 years power warranty; Waaree WSMDi-405 has a 27 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.

Shop prices: See 26 Waaree 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.