--- title: "JA Solar JAM78S30-585/MR vs JA Solar JAM78S30-600/MR - Solar Panel Comparison | ComparePV" description: "Compare JA Solar JAM78S30-585/MR vs JA Solar JAM78S30-600/MR 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-jam78s30-585-mr/ja-solar-jam78s30-600-mr" image: "https://comparepv.com/og/compare/panels/ja-solar-jam78s30-585-mr/ja-solar-jam78s30-600-mr.png" updated: 2026-09-11 --- # JA Solar JAM78S30-585/MR vs JA Solar JAM78S30-600/MR 600/MR leads on the differences that matter The largest is module efficiency: 0.60 pp more efficient. 16 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [JA Solar JAM78S30-585/MR](https://comparepv.com/panel/ja-solar-jam78s30-585-mr) | [JA Solar JAM78S30-600/MR](https://comparepv.com/panel/ja-solar-jam78s30-600-mr) | | Manufacturer | JA Solar | JA Solar | | Power | 585 Wp | 600 Wp | | Efficiency | 20.90 % | 21.50 % | | Technology | PERC | PERC | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 585/MR | 600/MR | Difference | | --- | --- | --- | --- | | Module efficiency | 20.90 % | 21.50 % | +0.60 pp for 600/MR | | Power density | 209.3 Wp/m² | 214.6 Wp/m² | +5.4 Wp/m² for 600/MR | | Rated power | 585 Wp | 600 Wp | +15 W for 600/MR | ## Every compared parameter | Parameter | 585/MR | 600/MR | | --- | --- | --- | | Rated power | 585 Wp | 600 Wp | | Module efficiency | 20.90 % | 21.50 % | | Power density | 209.3 Wp/m² | 214.6 Wp/m² | | Open-circuit voltage | 53.20 V | 53.50 V | | Voltage at max power | 44.56 V | 45.30 V | | Short-circuit current | 13.88 A | 14.03 A | | Current at max power | 13.13 A | 13.25 A | | Temperature coefficient | -0.350 %/°C | -0.350 %/°C | | Dimensions | 2465x1134x35 mm | 2465x1134x35 mm | | Module area | 2.795 m² | 2.795 m² | | Weight | 30.5 kg | 30.5 kg | | Weight per kWp | 52.1 kg/kWp | 50.8 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 | 156 | 156 | | 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 (-0.350 %/°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, 585/MR:** 18,959 kWh - **Cumulative output, 600/MR:** 19,445 kWh - **Gap:** 486 kWh ## Output when hot | Condition | Cell temperature | 585/MR | 600/MR | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 585 W | 600 W | 100.0% of rated power | | Cool, bright day | 40 °C | 554 W | 569 W | 94.8% of rated power | | Typical summer roof | 55 °C | 524 W | 537 W | 89.5% of rated power | | Hot roof | 70 °C | 493 W | 506 W | 84.2% of rated power | ## Against the whole database | Measure | 585/MR | 600/MR | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #10,148 | #8,022 | 14,129 | 600/MR leads by 2,126 places | | Power density | #10,074 | #8,265 | 14,129 | 600/MR leads by 1,809 places | | Heat behaviour | #10,489 | #10,489 | 14,129 | Tied - the same position in the database | | Weight | #5,648 | #4,253 | 14,129 | 600/MR leads by 1,395 places | | Warranty | #9,912 | #9,912 | 14,129 | Tied - the same position in the database | | Overall | #7,275 | #5,936 | 14,129 | 600/MR leads by 1,339 places | ## Questions ### Which panel is better: JA Solar JAM78S30-585/MR or JA Solar JAM78S30-600/MR? According to our database: **JA Solar JAM78S30-600/MR** has higher module efficiency (**21.50%** vs **20.90%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of JA Solar JAM78S30-585/MR and JA Solar JAM78S30-600/MR? **JA Solar JAM78S30-585/MR** has a module efficiency of **20.90%**, while **JA Solar JAM78S30-600/MR** is **21.50%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does JA Solar JAM78S30-585/MR use vs JA Solar JAM78S30-600/MR? **JA Solar JAM78S30-585/MR** uses **PERC** cells; **JA Solar JAM78S30-600/MR** 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 JAM78S30-585/MR and JA Solar JAM78S30-600/MR? **JA Solar JAM78S30-585/MR** has a **25 years** power warranty; **JA Solar JAM78S30-600/MR** 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 JAM78S30-585/MR vs JA Solar JAM78S30-605/MR](https://comparepv.com/compare/ja-solar-jam78s30-585-mr/ja-solar-jam78s30-605-mr) - 3 differences, the largest is module efficiency - [JA Solar JAM78S30-585/MR vs JA Solar JAM78S30-595/MR](https://comparepv.com/compare/ja-solar-jam78s30-585-mr/ja-solar-jam78s30-595-mr) - 3 differences, the largest is module efficiency - [JA Solar JAM78S30-585/MR vs JA Solar JAM78S30-590/MR](https://comparepv.com/compare/ja-solar-jam78s30-585-mr/ja-solar-jam78s30-590-mr) - One difference: module efficiency - [JA Solar JAM78S30-585/MR vs JA Solar JAM78S30-580/MR](https://comparepv.com/compare/ja-solar-jam78s30-585-mr/ja-solar-jam78s30-580-mr) - One difference: module efficiency - [JA Solar JAM78S30-585/MR vs JA Solar JAM66D46-740/LB](https://comparepv.com/compare/ja-solar-jam78s30-585-mr/ja-solar-jam66d46-740-lb) - 16 differences, the largest is module efficiency - [JA Solar JAM78S30-585/MR vs JA Solar JAM66D46-735/LB](https://comparepv.com/compare/ja-solar-jam78s30-585-mr/ja-solar-jam66d46-735-lb) - 16 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/ja-solar-jam78s30-585-mr/ja-solar-jam78s30-600-mr 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.