--- title: "JA Solar JAM72S40-600/LR vs JA Solar JAM72S42-650/LR - Solar Panel Comparison | ComparePV" description: "Compare JA Solar JAM72S40-600/LR vs JA Solar JAM72S42-650/LR 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-jam72s40-600-lr/ja-solar-jam72s42-650-lr" updated: 2026-09-11 --- # JA Solar JAM72S40-600/LR vs JA Solar JAM72S42-650/LR JAM72S42-650/LR leads on the differences that matter The largest is rated power: 50 W more power. 10 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [JA Solar JAM72S40-600/LR](https://comparepv.com/panel/ja-solar-jam72s40-600-lr) | [JA Solar JAM72S42-650/LR](https://comparepv.com/panel/ja-solar-jam72s42-650-lr) | | Manufacturer | JA Solar | JA Solar | | Power | 600 Wp | 650 Wp | | Efficiency | 22.70 % | 23.30 % | | Technology | TOPCon | TOPCon | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | JAM72S40-600/LR | JAM72S42-650/LR | Difference | | --- | --- | --- | --- | | Rated power | 600 Wp | 650 Wp | +50 W for JAM72S42-650/LR | | Module efficiency | 22.70 % | 23.30 % | +0.60 pp for JAM72S42-650/LR | | Weight | 24.3 kg | 29.6 kg | -5.3 kg for JAM72S40-600/LR | | Module area | 2.646 m² | 2.795 m² | 0.150 m² apart | | Power density | 226.8 Wp/m² | 232.5 Wp/m² | +5.7 Wp/m² for JAM72S42-650/LR | | Weight per kWp | 40.5 kg/kWp | 45.5 kg/kWp | -5.0 kg/kWp for JAM72S40-600/LR | | Short-circuit current | 14.48 A | 15.41 A | 0.93 A apart | | Dimensions | 2333x1134x30 mm | 2465x1134x30 mm | 2333x1134x30 mm vs 2465x1134x30 mm | | Current at max power | 13.71 A | 14.55 A | 0.84 A apart | ## Every compared parameter | Parameter | JAM72S40-600/LR | JAM72S42-650/LR | | --- | --- | --- | | Rated power | 600 Wp | 650 Wp | | Module efficiency | 22.70 % | 23.30 % | | Power density | 226.8 Wp/m² | 232.5 Wp/m² | | Open-circuit voltage | 52.40 V | 53.27 V | | Voltage at max power | 43.76 V | 44.67 V | | Short-circuit current | 14.48 A | 15.41 A | | Current at max power | 13.71 A | 14.55 A | | Temperature coefficient | -0.290 %/°C | -0.290 %/°C | | Dimensions | 2333x1134x30 mm | 2465x1134x30 mm | | Module area | 2.646 m² | 2.795 m² | | Weight | 24.3 kg | 29.6 kg | | Weight per kWp | 40.5 kg/kWp | 45.5 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 25 yrs | 25 yrs | | Annual degradation | 0.40 %/yr | 0.40 %/yr | | Cell technology | TOPCon | TOPCon | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 144 | 144 | | 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 (-0.290 %/°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, JAM72S40-600/LR:** 20,131 kWh - **Cumulative output, JAM72S42-650/LR:** 21,809 kWh - **Gap:** 1,678 kWh ## Output when hot | Condition | Cell temperature | JAM72S40-600/LR | JAM72S42-650/LR | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 600 W | 650 W | 100.0% of rated power | | Cool, bright day | 40 °C | 574 W | 622 W | 95.7% of rated power | | Typical summer roof | 55 °C | 548 W | 593 W | 91.3% of rated power | | Hot roof | 70 °C | 522 W | 565 W | 87.0% of rated power | ## Against the whole database | Measure | JAM72S40-600/LR | JAM72S42-650/LR | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #3,307 | #1,017 | 14,005 | JAM72S42-650/LR leads by 2,290 places | | Power density | #3,467 | #1,222 | 14,005 | JAM72S42-650/LR leads by 2,245 places | | Heat behaviour | #2,165 | #2,165 | 14,005 | Tied - the same position in the database | | Weight | #164 | #761 | 14,005 | JAM72S40-600/LR leads by 597 places | | Warranty | #9,798 | #9,798 | 14,005 | Tied - the same position in the database | | Overall | #4,350 | #2,158 | 14,005 | JAM72S42-650/LR leads by 2,192 places | ## Questions ### Which panel is better: JA Solar JAM72S40-600/LR or JA Solar JAM72S42-650/LR? According to our database: **JA Solar JAM72S42-650/LR** has higher module efficiency (**23.30%** vs **22.70%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of JA Solar JAM72S40-600/LR and JA Solar JAM72S42-650/LR? **JA Solar JAM72S40-600/LR** has a module efficiency of **22.70%**, while **JA Solar JAM72S42-650/LR** is **23.30%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does JA Solar JAM72S40-600/LR use vs JA Solar JAM72S42-650/LR? **JA Solar JAM72S40-600/LR** uses **TOPCon** cells; **JA Solar JAM72S42-650/LR** 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 JAM72S40-600/LR and JA Solar JAM72S42-650/LR? **JA Solar JAM72S40-600/LR** has a **25 years** power warranty; **JA Solar JAM72S42-650/LR** 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 - [JA Solar JAM72S40-600/LR vs JA Solar JAM72S42-645/LR](https://comparepv.com/compare/ja-solar-jam72s40-600-lr/ja-solar-jam72s42-645-lr) - 9 differences, the largest is rated power - [JA Solar JAM72S40-600/LR vs JA Solar JAM72S42-640/LR](https://comparepv.com/compare/ja-solar-jam72s40-600-lr/ja-solar-jam72s42-640-lr) - 8 differences, the largest is rated power - [JA Solar JAM72S40-600/LR vs JA Solar JAM72S42-635/LR](https://comparepv.com/compare/ja-solar-jam72s40-600-lr/ja-solar-jam72s42-635-lr) - 7 differences, the largest is rated power - [JA Solar JAM72S40-600/LR vs JA Solar JAM72S42-630/LR](https://comparepv.com/compare/ja-solar-jam72s40-600-lr/ja-solar-jam72s42-630-lr) - 8 differences, the largest is rated power - [JA Solar JAM72S40-600/LR vs JA Solar JAM72S42-625/LR](https://comparepv.com/compare/ja-solar-jam72s40-600-lr/ja-solar-jam72s42-625-lr) - 9 differences, the largest is weight - [JA Solar JAM72S40-600/LR vs JA Solar JAM72S40-605/LR](https://comparepv.com/compare/ja-solar-jam72s40-600-lr/ja-solar-jam72s40-605-lr) - One difference: module efficiency --- Source: https://comparepv.com/compare/ja-solar-jam72s40-600-lr/ja-solar-jam72s42-650-lr 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.