--- title: "Canadian Solar CS6.2-66HB-620 vs Canadian Solar CS6.2-66HB-635 - Solar Panel Comparison | ComparePV" description: "Compare Canadian Solar CS6.2-66HB-620 vs Canadian Solar CS6.2-66HB-635 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-cs6-2-66hb-620/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-635" image: "https://comparepv.com/og/compare/panels/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-620/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-635.png" updated: 2026-09-11 --- # Canadian Solar CS6.2-66HB-620 vs Canadian Solar CS6.2-66HB-635 635 leads on the differences that matter The largest is module efficiency: 0.50 pp more efficient. 16 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Canadian Solar CS6.2-66HB-620](https://comparepv.com/panel/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-620) | [Canadian Solar CS6.2-66HB-635](https://comparepv.com/panel/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-635) | | Manufacturer | Canadian Solar | Canadian Solar | | Power | 620 Wp | 635 Wp | | Efficiency | 23.00 % | 23.50 % | | Technology | HJT | HJT | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 620 | 635 | Difference | | --- | --- | --- | --- | | Module efficiency | 23.00 % | 23.50 % | +0.50 pp for 635 | | Power density | 229.5 Wp/m² | 235.1 Wp/m² | +5.6 Wp/m² for 635 | | Rated power | 620 Wp | 635 Wp | +15 W for 635 | ## Every compared parameter | Parameter | 620 | 635 | | --- | --- | --- | | Rated power | 620 Wp | 635 Wp | | Module efficiency | 23.00 % | 23.50 % | | Power density | 229.5 Wp/m² | 235.1 Wp/m² | | Open-circuit voltage | 50.10 V | 50.30 V | | Voltage at max power | 42.60 V | 42.70 V | | Short-circuit current | 15.65 A | 15.92 A | | Current at max power | 14.58 A | 14.88 A | | Temperature coefficient | -0.240 %/°C | -0.240 %/°C | | Dimensions | 2382x1134x30 mm | 2382x1134x30 mm | | Module area | 2.701 m² | 2.701 m² | | Weight | 32.8 kg | 32.8 kg | | Weight per kWp | 52.9 kg/kWp | 51.7 kg/kWp | | Product warranty | 15 yrs | 15 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.30 %/yr | 0.30 %/yr | | Cell technology | HJT | HJT | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 132 | 132 | | Bifacial | Yes | Yes | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year Same temp coeff. for both panels (-0.240 %/°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, 620:** 21,126 kWh - **Cumulative output, 635:** 21,637 kWh - **Gap:** 511 kWh ## Output when hot | Condition | Cell temperature | 620 | 635 | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 620 W | 635 W | 100.0% of rated power | | Cool, bright day | 40 °C | 598 W | 612 W | 96.4% of rated power | | Typical summer roof | 55 °C | 575 W | 589 W | 92.8% of rated power | | Hot roof | 70 °C | 553 W | 566 W | 89.2% of rated power | ## Against the whole database | Measure | 620 | 635 | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #1,970 | #749 | 14,129 | 635 leads by 1,221 places | | Power density | #2,243 | #777 | 14,129 | 635 leads by 1,466 places | | Heat behaviour | #13 | #13 | 14,129 | Tied - the same position in the database | | Weight | #6,673 | #5,050 | 14,129 | 635 leads by 1,623 places | | Warranty | #21 | #21 | 14,129 | Tied - the same position in the database | | Overall | #2,057 | #1,463 | 14,129 | 635 leads by 594 places | ## Questions ### Which panel is better: Canadian Solar CS6.2-66HB-620 or Canadian Solar CS6.2-66HB-635? According to our database: **Canadian Solar CS6.2-66HB-635** has higher module efficiency (**23.50%** vs **23.00%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Canadian Solar CS6.2-66HB-620 and Canadian Solar CS6.2-66HB-635? **Canadian Solar CS6.2-66HB-620** has a module efficiency of **23.00%**, while **Canadian Solar CS6.2-66HB-635** is **23.50%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Canadian Solar CS6.2-66HB-620 use vs Canadian Solar CS6.2-66HB-635? **Canadian Solar CS6.2-66HB-620** uses **HJT** cells; **Canadian Solar CS6.2-66HB-635** uses **HJT**. 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 CS6.2-66HB-620 and Canadian Solar CS6.2-66HB-635? **Canadian Solar CS6.2-66HB-620** has a **30 years** power warranty; **Canadian Solar CS6.2-66HB-635** 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 Canadian Solar CS6.2-66HB-620 and Canadian Solar CS6.2-66HB-635 bifacial panels? Both **Canadian Solar CS6.2-66HB-620** and **Canadian Solar CS6.2-66HB-635** 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. ## Related comparisons - [Canadian Solar CS6.2-66HB-620 vs Canadian Solar CS6.2-66HB-645](https://comparepv.com/compare/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-620/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-645) - 4 differences, the largest is module efficiency - [Canadian Solar CS6.2-66HB-620 vs Canadian Solar CS6.2-66HB-640](https://comparepv.com/compare/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-620/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-640) - 3 differences, the largest is module efficiency - [Canadian Solar CS6.2-66HB-620 vs Canadian Solar CS6.2-66HB-630](https://comparepv.com/compare/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-620/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-630) - 3 differences, the largest is module efficiency - [Canadian Solar CS6.2-66HB-620 vs Canadian Solar CS6.2-66HB-625](https://comparepv.com/compare/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-620/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-625) - The same specification on paper - [Canadian Solar CS6.2-66HB-620 vs Canadian Solar CS7N-730TB-AG](https://comparepv.com/compare/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-620/csi-solar-co-ltd-canadian-solar-cs7n-730tb-ag) - 14 differences, the largest is temperature coefficient - [Canadian Solar CS6.2-66HB-620 vs Canadian Solar CS7N-725TB-AG](https://comparepv.com/compare/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-620/csi-solar-co-ltd-canadian-solar-cs7n-725tb-ag) - 14 differences, the largest is temperature coefficient --- Source: https://comparepv.com/compare/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-620/csi-solar-co-ltd-canadian-solar-cs6-2-66hb-635 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.