--- title: "JA Solar JAM72D42-630/LB vs JA Solar JAM72D42-635/LB - Solar Panel Comparison | ComparePV" description: "Compare JA Solar JAM72D42-630/LB vs JA Solar JAM72D42-635/LB side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/ja-solar-jam72d42-630-lb/ja-solar-jam72d42-635-lb" updated: 2026-09-11 --- # JA Solar JAM72D42-630/LB vs JA Solar JAM72D42-635/LB 635/LB leads on the differences that matter The largest is module efficiency: 0.20 pp more efficient. 18 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [JA Solar JAM72D42-630/LB](https://comparepv.com/panel/ja-solar-jam72d42-630-lb) | [JA Solar JAM72D42-635/LB](https://comparepv.com/panel/ja-solar-jam72d42-635-lb) | | Manufacturer | JA Solar | JA Solar | | Power | 630 Wp | 635 Wp | | Efficiency | 22.50 % | 22.70 % | | Technology | TOPCon | TOPCon | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 630/LB | 635/LB | Difference | | --- | --- | --- | --- | | Module efficiency | 22.50 % | 22.70 % | +0.20 pp for 635/LB | ## Every compared parameter | Parameter | 630/LB | 635/LB | | --- | --- | --- | | Rated power | 630 Wp | 635 Wp | | Module efficiency | 22.50 % | 22.70 % | | Power density | 225.4 Wp/m² | 227.2 Wp/m² | | Open-circuit voltage | 52.47 V | 52.67 V | | Voltage at max power | 43.90 V | 44.10 V | | Short-circuit current | 15.21 A | 15.26 A | | Current at max power | 14.35 A | 14.40 A | | Temperature coefficient | -0.290 %/°C | -0.290 %/°C | | Dimensions | 2465x1134x30 mm | 2465x1134x30 mm | | Module area | 2.795 m² | 2.795 m² | | Weight | 34.6 kg | 34.6 kg | | Weight per kWp | 54.9 kg/kWp | 54.5 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.40 %/yr | 0.40 %/yr | | Cell technology | TOPCon | TOPCon | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 144 | 144 | | 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 (-0.290 %/°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, 630/LB:** 21,138 kWh - **Cumulative output, 635/LB:** 21,306 kWh - **Gap:** 168 kWh ## Output when hot | Condition | Cell temperature | 630/LB | 635/LB | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 630 W | 635 W | 100.0% of rated power | | Cool, bright day | 40 °C | 603 W | 607 W | 95.7% of rated power | | Typical summer roof | 55 °C | 575 W | 580 W | 91.3% of rated power | | Hot roof | 70 °C | 548 W | 552 W | 87.0% of rated power | ## Against the whole database | Measure | 630/LB | 635/LB | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #4,222 | #3,307 | 14,005 | 635/LB leads by 915 places | | Power density | #3,907 | #3,252 | 14,005 | 635/LB leads by 655 places | | Heat behaviour | #2,165 | #2,165 | 14,005 | Tied - the same position in the database | | Weight | #9,305 | #8,832 | 14,005 | 635/LB leads by 473 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #2,749 | #2,396 | 14,005 | 635/LB leads by 353 places | ## Questions ### Which panel is better: JA Solar JAM72D42-630/LB or JA Solar JAM72D42-635/LB? According to our database: **JA Solar JAM72D42-635/LB** has higher module efficiency (**22.70%** vs **22.50%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of JA Solar JAM72D42-630/LB and JA Solar JAM72D42-635/LB? **JA Solar JAM72D42-630/LB** has a module efficiency of **22.50%**, while **JA Solar JAM72D42-635/LB** is **22.70%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does JA Solar JAM72D42-630/LB use vs JA Solar JAM72D42-635/LB? **JA Solar JAM72D42-630/LB** uses **TOPCon** cells; **JA Solar JAM72D42-635/LB** uses **TOPCon**. 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 JA Solar JAM72D42-630/LB and JA Solar JAM72D42-635/LB? **JA Solar JAM72D42-630/LB** has a **30 years** power warranty; **JA Solar JAM72D42-635/LB** 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 JA Solar JAM72D42-630/LB and JA Solar JAM72D42-635/LB bifacial panels? Both **JA Solar JAM72D42-630/LB** and **JA Solar JAM72D42-635/LB** 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 - [JA Solar JAM72D42-630/LB vs JA Solar JAM72D42-650/LB](https://comparepv.com/compare/ja-solar-jam72d42-630-lb/ja-solar-jam72d42-650-lb) - 3 differences, the largest is module efficiency - [JA Solar JAM72D42-630/LB vs JA Solar JAM72D42-645/LB](https://comparepv.com/compare/ja-solar-jam72d42-630-lb/ja-solar-jam72d42-645-lb) - 3 differences, the largest is module efficiency - [JA Solar JAM72D42-630/LB vs JA Solar JAM72D42-640/LB](https://comparepv.com/compare/ja-solar-jam72d42-630-lb/ja-solar-jam72d42-640-lb) - 3 differences, the largest is module efficiency - [JA Solar JAM72D42-630/LB vs JA Solar JAM72D42-625/LB](https://comparepv.com/compare/ja-solar-jam72d42-630-lb/ja-solar-jam72d42-625-lb) - The same specification on paper - [JA Solar JAM72D42-630/LB vs JA Solar JAM72D40-615/LB](https://comparepv.com/compare/ja-solar-jam72d42-630-lb/ja-solar-jam72d40-615-lb) - 8 differences, the largest is module efficiency - [JA Solar JAM72D42-630/LB vs JA Solar JAM72D40-610/LB](https://comparepv.com/compare/ja-solar-jam72d42-630-lb/ja-solar-jam72d40-610-lb) - 8 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/ja-solar-jam72d42-630-lb/ja-solar-jam72d42-635-lb 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.