--- title: "JA Solar JAM66D46-740/LB vs JA Solar JAM72D30-580/LB/1500V - Solar Panel Comparison | ComparePV" description: "Compare JA Solar JAM66D46-740/LB vs JA Solar JAM72D30-580/LB/1500V 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-jam66d46-740-lb/ja-solar-jam72d30-580-lb-1500v" updated: 2026-09-11 --- # JA Solar JAM66D46-740/LB vs JA Solar JAM72D30-580/LB/1500V JAM66D46-740/LB leads on the differences that matter The largest is module efficiency: 1.90 pp more efficient. 5 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [JA Solar JAM66D46-740/LB](https://comparepv.com/panel/ja-solar-jam66d46-740-lb) | [JA Solar JAM72D30-580/LB/1500V](https://comparepv.com/panel/ja-solar-jam72d30-580-lb-1500v) | | Manufacturer | JA Solar | JA Solar | | Power | 740 Wp | 580 Wp | | Efficiency | 23.80 % | 21.90 % | | Technology | TOPCon | PERC | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | JAM66D46-740/LB | JAM72D30-580/LB/1500V | Difference | | --- | --- | --- | --- | | Module efficiency | 23.80 % | 21.90 % | +1.90 pp for JAM66D46-740/LB | | Temperature coefficient | -0.290 %/°C | -0.350 %/°C | +0.060 %/°C for JAM66D46-740/LB | | Rated power | 740 Wp | 580 Wp | +160 W for JAM66D46-740/LB | | Power density | 238.2 Wp/m² | 219.2 Wp/m² | +19.0 Wp/m² for JAM66D46-740/LB | | Weight | 38.2 kg | 32.5 kg | -5.7 kg for JAM72D30-580/LB/1500V | | Short-circuit current | 18.73 A | 14.50 A | 4.23 A apart | | Module area | 3.106 m² | 2.646 m² | 0.461 m² apart | | Weight per kWp | 51.6 kg/kWp | 56.0 kg/kWp | -4.4 kg/kWp for JAM66D46-740/LB | | Cell technology | TOPCon | PERC | TOPCon vs PERC | | Current at max power | 17.64 A | 13.73 A | 3.91 A apart | | Cell count | 132 | 144 | 12 cells apart | | Annual degradation | 0.40 %/yr | 0.45 %/yr | -0.05 %/yr for JAM66D46-740/LB | | Open-circuit voltage | 49.80 V | 51.04 V | 1.24 V apart | | Dimensions | 2384x1303x33 mm | 2333x1134x30 mm | 2384x1303x33 mm vs 2333x1134x30 mm | ## Every compared parameter | Parameter | JAM66D46-740/LB | JAM72D30-580/LB/1500V | | --- | --- | --- | | Rated power | 740 Wp | 580 Wp | | Module efficiency | 23.80 % | 21.90 % | | Power density | 238.2 Wp/m² | 219.2 Wp/m² | | Open-circuit voltage | 49.80 V | 51.04 V | | Voltage at max power | 41.96 V | 42.24 V | | Short-circuit current | 18.73 A | 14.50 A | | Current at max power | 17.64 A | 13.73 A | | Temperature coefficient | -0.290 %/°C | -0.350 %/°C | | Dimensions | 2384x1303x33 mm | 2333x1134x30 mm | | Module area | 3.106 m² | 2.646 m² | | Weight | 38.2 kg | 32.5 kg | | Weight per kWp | 51.6 kg/kWp | 56.0 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.40 %/yr | 0.45 %/yr | | Cell technology | TOPCon | PERC | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 132 | 144 | | Bifacial | Yes | Yes | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year - **Cumulative output, JAM66D46-740/LB:** 24,828 kWh - **Cumulative output, JAM72D30-580/LB/1500V:** 19,100 kWh - **Gap:** 5,728 kWh ## Output when hot | Condition | Cell temperature | JAM66D46-740/LB | JAM72D30-580/LB/1500V | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 740 W | 580 W | 100.0% of rated power | | Cool, bright day | 40 °C | 708 W | 550 W | 94.8% of rated power | | Typical summer roof | 55 °C | 676 W | 519 W | 89.5% of rated power | | Hot roof | 70 °C | 643 W | 489 W | 84.2% of rated power | ## Against the whole database | Measure | JAM66D46-740/LB | JAM72D30-580/LB/1500V | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #433 | #6,783 | 14,005 | JAM66D46-740/LB leads by 6,350 places | | Power density | #431 | #6,733 | 14,005 | JAM66D46-740/LB leads by 6,302 places | | Heat behaviour | #2,165 | #10,419 | 14,005 | JAM66D46-740/LB leads by 8,254 places | | Weight | #4,997 | #10,343 | 14,005 | JAM66D46-740/LB leads by 5,346 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #185 | #5,178 | 14,005 | JAM66D46-740/LB leads by 4,993 places | ## Questions ### Which panel is better: JA Solar JAM66D46-740/LB or JA Solar JAM72D30-580/LB/1500V? According to our database: **JA Solar JAM66D46-740/LB** has higher module efficiency (**23.80%** vs **21.90%**); **JA Solar JAM66D46-740/LB** tolerates heat better (temp coeff **-0.290%/°C** vs **-0.350%/°C**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of JA Solar JAM66D46-740/LB and JA Solar JAM72D30-580/LB/1500V? **JA Solar JAM66D46-740/LB** has a module efficiency of **23.80%**, while **JA Solar JAM72D30-580/LB/1500V** is **21.90%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does JA Solar JAM66D46-740/LB use vs JA Solar JAM72D30-580/LB/1500V? **JA Solar JAM66D46-740/LB** uses **TOPCon** cells; **JA Solar JAM72D30-580/LB/1500V** 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 JA Solar JAM66D46-740/LB and JA Solar JAM72D30-580/LB/1500V? **JA Solar JAM66D46-740/LB** has a **30 years** power warranty; **JA Solar JAM72D30-580/LB/1500V** 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 JAM66D46-740/LB and JA Solar JAM72D30-580/LB/1500V bifacial panels? Both **JA Solar JAM66D46-740/LB** and **JA Solar JAM72D30-580/LB/1500V** 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 JAM66D46-740/LB vs JA Solar JAM66D46-735/LB](https://comparepv.com/compare/ja-solar-jam66d46-740-lb/ja-solar-jam66d46-735-lb) - The same specification on paper - [JA Solar JAM66D46-740/LB vs JA Solar JAM66D46-730/LB](https://comparepv.com/compare/ja-solar-jam66d46-740-lb/ja-solar-jam66d46-730-lb) - 3 differences, the largest is module efficiency - [JA Solar JAM66D46-740/LB vs JA Solar JAM66D46-725/LB](https://comparepv.com/compare/ja-solar-jam66d46-740-lb/ja-solar-jam66d46-725-lb) - 3 differences, the largest is module efficiency - [JA Solar JAM66D46-740/LB vs JA Solar JAM66D46-720/LB](https://comparepv.com/compare/ja-solar-jam66d46-740-lb/ja-solar-jam66d46-720-lb) - 3 differences, the largest is module efficiency - [JA Solar JAM66D46-740/LB vs JA Solar JAM66D46-715/LB](https://comparepv.com/compare/ja-solar-jam66d46-740-lb/ja-solar-jam66d46-715-lb) - 4 differences, the largest is module efficiency - [JA Solar JAM66D46-740/LB vs JA Solar JAM66D46-710/LB](https://comparepv.com/compare/ja-solar-jam66d46-740-lb/ja-solar-jam66d46-710-lb) - 6 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/ja-solar-jam66d46-740-lb/ja-solar-jam72d30-580-lb-1500v 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.