--- title: "Canadian Solar CS7L-615MS vs Canadian Solar CS7N-665MS - Solar Panel Comparison | ComparePV" description: "Compare Canadian Solar CS7L-615MS vs Canadian Solar CS7N-665MS side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/csi-solar-co-ltd-canadian-solar-cs7l-615ms/csi-solar-co-ltd-canadian-solar-cs7n-665ms" updated: 2026-09-11 --- # Canadian Solar CS7L-615MS vs Canadian Solar CS7N-665MS 9 differences, and they point both ways The largest is rated power: 50 W more power. 10 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Canadian Solar CS7L-615MS](https://comparepv.com/panel/csi-solar-co-ltd-canadian-solar-cs7l-615ms) | [Canadian Solar CS7N-665MS](https://comparepv.com/panel/csi-solar-co-ltd-canadian-solar-cs7n-665ms) | | Manufacturer | Canadian Solar | Canadian Solar | | Power | 615 Wp | 665 Wp | | Efficiency | 21.70 % | 21.40 % | | Technology | PERC | PERC | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | CS7L-615MS | CS7N-665MS | Difference | | --- | --- | --- | --- | | Rated power | 615 Wp | 665 Wp | +50 W for CS7N-665MS | | Weight | 30.9 kg | 33.9 kg | -3.0 kg for CS7L-615MS | | Module area | 2.830 m² | 3.106 m² | 0.276 m² apart | | Module efficiency | 21.70 % | 21.40 % | +0.30 pp for CS7L-615MS | | Open-circuit voltage | 41.90 V | 45.60 V | 3.70 V apart | | Power density | 217.3 Wp/m² | 214.1 Wp/m² | +3.2 Wp/m² for CS7L-615MS | | Cell count | 120 | 132 | 12 cells apart | | Voltage at max power | 35.40 V | 38.50 V | 3.10 V apart | | Dimensions | 2172x1303x35 mm | 2384x1303x35 mm | 2172x1303x35 mm vs 2384x1303x35 mm | ## Every compared parameter | Parameter | CS7L-615MS | CS7N-665MS | | --- | --- | --- | | Rated power | 615 Wp | 665 Wp | | Module efficiency | 21.70 % | 21.40 % | | Power density | 217.3 Wp/m² | 214.1 Wp/m² | | Open-circuit voltage | 41.90 V | 45.60 V | | Voltage at max power | 35.40 V | 38.50 V | | Short-circuit current | 18.62 A | 18.51 A | | Current at max power | 17.38 A | 17.28 A | | Temperature coefficient | -0.340 %/°C | -0.340 %/°C | | Dimensions | 2172x1303x35 mm | 2384x1303x35 mm | | Module area | 2.830 m² | 3.106 m² | | Weight | 30.9 kg | 33.9 kg | | Weight per kWp | 50.2 kg/kWp | 51.0 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 25 yrs | 25 yrs | | Annual degradation | 0.55 %/yr | 0.55 %/yr | | Cell technology | PERC | PERC | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 120 | 132 | | Bifacial | No | No | ## Thirty-year yield 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. - **Cumulative output, CS7L-615MS:** 19,932 kWh - **Cumulative output, CS7N-665MS:** 21,552 kWh - **Gap:** 1,620 kWh ## Output when hot | Condition | Cell temperature | CS7L-615MS | CS7N-665MS | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 615 W | 665 W | 100.0% of rated power | | Cool, bright day | 40 °C | 584 W | 631 W | 94.9% of rated power | | Typical summer roof | 55 °C | 552 W | 597 W | 89.8% of rated power | | Hot roof | 70 °C | 521 W | 563 W | 84.7% of rated power | ## Against the whole database | Measure | CS7L-615MS | CS7N-665MS | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #7,421 | #8,323 | 14,005 | CS7L-615MS leads by 902 places | | Power density | #7,329 | #8,250 | 14,005 | CS7L-615MS leads by 921 places | | Heat behaviour | #8,778 | #8,778 | 14,005 | Tied - the same position in the database | | Weight | #3,688 | #4,337 | 14,005 | CS7L-615MS leads by 649 places | | Warranty | #9,798 | #9,798 | 14,005 | Tied - the same position in the database | | Overall | #5,126 | #3,807 | 14,005 | CS7N-665MS leads by 1,319 places | ## Questions ### Which panel is better: Canadian Solar CS7L-615MS or Canadian Solar CS7N-665MS? According to our database: **Canadian Solar CS7L-615MS** has higher module efficiency (**21.70%** 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 CS7L-615MS and Canadian Solar CS7N-665MS? **Canadian Solar CS7L-615MS** has a module efficiency of **21.70%**, while **Canadian Solar CS7N-665MS** is **21.40%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Canadian Solar CS7L-615MS use vs Canadian Solar CS7N-665MS? **Canadian Solar CS7L-615MS** uses **PERC** cells; **Canadian Solar CS7N-665MS** 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 CS7L-615MS and Canadian Solar CS7N-665MS? **Canadian Solar CS7L-615MS** has a **25 years** power warranty; **Canadian Solar CS7N-665MS** 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. ## Related comparisons - [Canadian Solar CS7L-615MS vs Canadian Solar CS7N-675MS](https://comparepv.com/compare/csi-solar-co-ltd-canadian-solar-cs7l-615ms/csi-solar-co-ltd-canadian-solar-cs7n-675ms) - 7 differences, the largest is rated power - [Canadian Solar CS7L-615MS vs Canadian Solar CS7N-670MS](https://comparepv.com/compare/csi-solar-co-ltd-canadian-solar-cs7l-615ms/csi-solar-co-ltd-canadian-solar-cs7n-670ms) - 7 differences, the largest is rated power - [Canadian Solar CS7L-615MS vs Canadian Solar CS7N-660MS](https://comparepv.com/compare/csi-solar-co-ltd-canadian-solar-cs7l-615ms/csi-solar-co-ltd-canadian-solar-cs7n-660ms) - 9 differences, the largest is rated power - [Canadian Solar CS7L-615MS vs Canadian Solar CS7N-655MS](https://comparepv.com/compare/csi-solar-co-ltd-canadian-solar-cs7l-615ms/csi-solar-co-ltd-canadian-solar-cs7n-655ms) - 9 differences, the largest is rated power - [Canadian Solar CS7L-615MS vs Canadian Solar CS7N-650MS](https://comparepv.com/compare/csi-solar-co-ltd-canadian-solar-cs7l-615ms/csi-solar-co-ltd-canadian-solar-cs7n-650ms) - 9 differences, the largest is module efficiency - [Canadian Solar CS7L-615MS vs Canadian Solar CS7N-645MS](https://comparepv.com/compare/csi-solar-co-ltd-canadian-solar-cs7l-615ms/csi-solar-co-ltd-canadian-solar-cs7n-645ms) - 10 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/csi-solar-co-ltd-canadian-solar-cs7l-615ms/csi-solar-co-ltd-canadian-solar-cs7n-665ms Not in this file, on the page: the thirty-year yield curve year by year at a cell temperature you pick and a written summary generated on request.