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665MS vs 670MS 18 of 19 identical Swap Change panels

Canadian Solar CS7N-665MS vs Canadian Solar CS7N-670MS

Canadian Solar CS7N-665MS
CS7N-665MS
665 Wp 21.40 % PERC
VS
Canadian Solar CS7N-670MS
CS7N-670MS
670 Wp 21.60 % PERC
The verdict

670MS 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 665MS 670MS Difference
Module efficiency 21.40 % 21.60 % 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 (-0.340 %/°C), so a warmer roof scales both curves by the same factor: the totals fall together and neither panel gains on the other.
665MS
21,552 kWh
670MS
21,714 kWh
Lifetime gap
162 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 665MS 670MS
Standard test conditions 25 °C 100.0% of rated power 665 W 670 W
Cool, bright day 40 °C 94.9% of rated power 631 W 636 W
Typical summer roof 55 °C 89.8% of rated power 597 W 602 W
Hot roof 70 °C 84.7% of rated power 563 W 567 W
03

Full specification

Parameter 665MS 670MS Difference
Power and efficiency
Rated power 665 Wp 670 Wp Effectively the same
Module efficiency 21.40 % 21.60 % +0.20 pp for 670MS
Power density 214.1 Wp/m² 215.7 Wp/m² Effectively the same
Open-circuit voltage 45.60 V 45.80 V Effectively the same
Voltage at max power 38.50 V 38.70 V Effectively the same
Short-circuit current 18.51 A 18.55 A Effectively the same
Current at max power 17.28 A 17.32 A Effectively the same
Temperature
Temperature coefficient -0.340 %/°C -0.340 %/°C Same
Mechanical
Dimensions 2384x1303x35 mm 2384x1303x35 mm Same
Module area 3.106 m² 3.106 m² Same
Weight 33.9 kg 33.9 kg Same
Weight per kWp 51.0 kg/kWp 50.6 kg/kWp Effectively the same
Warranty and degradation
Product warranty 12 yrs 12 yrs Same
Performance warranty 25 yrs 25 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
#8,323 vs #7,652
670MS leads by 671 places
Power density
#8,250 vs #7,644
670MS leads by 606 places
Heat behaviour
#8,778 vs #8,778
Tied - the same position in the database
Weight
#4,337 vs #4,014
670MS leads by 323 places
Warranty
#9,798 vs #9,798
Tied - the same position in the database
Overall
#3,807 vs #3,373
670MS leads by 434 places
05

More useful comparisons

Open the full database
Same series, other bin
Canadian Solar CS7N-665MS vs Canadian Solar CS7N-675MS
3 differences, the largest is module efficiency
Same series, other bin
Canadian Solar CS7N-665MS vs Canadian Solar CS7N-660MS
One difference: module efficiency
Same series, other bin
Canadian Solar CS7N-665MS vs Canadian Solar CS7N-655MS
3 differences, the largest is module efficiency
Same series, other bin
Canadian Solar CS7N-665MS vs Canadian Solar CS7N-650MS
3 differences, the largest is module efficiency
Same series, other bin
Canadian Solar CS7N-665MS vs Canadian Solar CS7N-645MS
3 differences, the largest is module efficiency
Same series, other bin
Canadian Solar CS7N-665MS vs Canadian Solar CS7L-615MS
9 differences, the largest is rated power
06

Written summary

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07

Questions about this pairing

Which panel is better: Canadian Solar CS7N-665MS or Canadian Solar CS7N-670MS?
According to our database: Canadian Solar CS7N-670MS has higher module efficiency (21.60% vs 21.40%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of Canadian Solar CS7N-665MS and Canadian Solar CS7N-670MS?
Canadian Solar CS7N-665MS has a module efficiency of 21.40%, while Canadian Solar CS7N-670MS is 21.60%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does Canadian Solar CS7N-665MS use vs Canadian Solar CS7N-670MS?
Canadian Solar CS7N-665MS uses PERC cells; Canadian Solar CS7N-670MS 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 Canadian Solar CS7N-665MS and Canadian Solar CS7N-670MS?
Canadian Solar CS7N-665MS has a 25 years power warranty; Canadian Solar CS7N-670MS has a 25 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 39 Canadian Solar 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.