--- title: "JA Solar JAM78D30-585/MB/1500V vs JA Solar JAM78D30-605/MB/1500V - Solar Panel Comparison | ComparePV" description: "Compare JA Solar JAM78D30-585/MB/1500V vs JA Solar JAM78D30-605/MB/1500V side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/shanghai-ja-solar-technology-co-ltd-jam78d30-585-mb-1500v/shanghai-ja-solar-technology-co-ltd-jam78d30-605-mb-1500v" image: "https://comparepv.com/og/compare/panels/shanghai-ja-solar-technology-co-ltd-jam78d30-585-mb-1500v/shanghai-ja-solar-technology-co-ltd-jam78d30-605-mb-1500v.png" updated: 2026-09-11 --- # JA Solar JAM78D30-585/MB/1500V vs JA Solar JAM78D30-605/MB/1500V 605/MB/1500V leads on the differences that matter The largest is module efficiency: 0.70 pp more efficient. 16 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [JA Solar JAM78D30-585/MB/1500V](https://comparepv.com/panel/shanghai-ja-solar-technology-co-ltd-jam78d30-585-mb-1500v) | [JA Solar JAM78D30-605/MB/1500V](https://comparepv.com/panel/shanghai-ja-solar-technology-co-ltd-jam78d30-605-mb-1500v) | | Manufacturer | JA Solar | JA Solar | | Power | 585 Wp | 605 Wp | | Efficiency | 20.90 % | 21.60 % | | Technology | PERC | PERC | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 585/MB/1500V | 605/MB/1500V | Difference | | --- | --- | --- | --- | | Module efficiency | 20.90 % | 21.60 % | +0.70 pp for 605/MB/1500V | | Power density | 209.3 Wp/m² | 216.4 Wp/m² | +7.2 Wp/m² for 605/MB/1500V | | Rated power | 585 Wp | 605 Wp | +20 W for 605/MB/1500V | ## Every compared parameter | Parameter | 585/MB/1500V | 605/MB/1500V | | --- | --- | --- | | Rated power | 585 Wp | 605 Wp | | Module efficiency | 20.90 % | 21.60 % | | Power density | 209.3 Wp/m² | 216.4 Wp/m² | | Open-circuit voltage | 53.20 V | 53.61 V | | Voltage at max power | 44.56 V | 45.53 V | | Short-circuit current | 13.88 A | 14.08 A | | Current at max power | 13.13 A | 13.29 A | | Temperature coefficient | -0.350 %/°C | -0.350 %/°C | | Dimensions | 2465x1134x35 mm | 2465x1134x35 mm | | Module area | 2.795 m² | 2.795 m² | | Weight | 33.4 kg | 33.4 kg | | Weight per kWp | 57.1 kg/kWp | 55.2 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.45 %/yr | 0.45 %/yr | | Cell technology | PERC | PERC | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 156 | 156 | | 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 (-0.350 %/°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/MB/1500V:** 19,265 kWh - **Cumulative output, 605/MB/1500V:** 19,923 kWh - **Gap:** 658 kWh ## Output when hot | Condition | Cell temperature | 585/MB/1500V | 605/MB/1500V | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 585 W | 605 W | 100.0% of rated power | | Cool, bright day | 40 °C | 554 W | 573 W | 94.8% of rated power | | Typical summer roof | 55 °C | 524 W | 541 W | 89.5% of rated power | | Hot roof | 70 °C | 493 W | 510 W | 84.2% of rated power | ## Against the whole database | Measure | 585/MB/1500V | 605/MB/1500V | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #10,148 | #7,716 | 14,129 | 605/MB/1500V leads by 2,432 places | | Power density | #10,074 | #7,665 | 14,129 | 605/MB/1500V leads by 2,409 places | | Heat behaviour | #10,489 | #10,489 | 14,129 | Tied - the same position in the database | | Weight | #11,132 | #9,735 | 14,129 | 605/MB/1500V leads by 1,397 places | | Warranty | #21 | #21 | 14,129 | Tied - the same position in the database | | Overall | #6,198 | #4,714 | 14,129 | 605/MB/1500V leads by 1,484 places | ## Questions ### Which panel is better: JA Solar JAM78D30-585/MB/1500V or JA Solar JAM78D30-605/MB/1500V? According to our database: **JA Solar JAM78D30-605/MB/1500V** has higher module efficiency (**21.60%** 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 JAM78D30-585/MB/1500V and JA Solar JAM78D30-605/MB/1500V? **JA Solar JAM78D30-585/MB/1500V** has a module efficiency of **20.90%**, while **JA Solar JAM78D30-605/MB/1500V** is **21.60%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does JA Solar JAM78D30-585/MB/1500V use vs JA Solar JAM78D30-605/MB/1500V? **JA Solar JAM78D30-585/MB/1500V** uses **PERC** cells; **JA Solar JAM78D30-605/MB/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 JAM78D30-585/MB/1500V and JA Solar JAM78D30-605/MB/1500V? **JA Solar JAM78D30-585/MB/1500V** has a **30 years** power warranty; **JA Solar JAM78D30-605/MB/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 JAM78D30-585/MB/1500V and JA Solar JAM78D30-605/MB/1500V bifacial panels? Both **JA Solar JAM78D30-585/MB/1500V** and **JA Solar JAM78D30-605/MB/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 JAM78D30-585/MB/1500V vs JA Solar JAM78D30-600/MB/1500V](https://comparepv.com/compare/shanghai-ja-solar-technology-co-ltd-jam78d30-585-mb-1500v/shanghai-ja-solar-technology-co-ltd-jam78d30-600-mb-1500v) - 3 differences, the largest is module efficiency - [JA Solar JAM78D30-585/MB/1500V vs JA Solar JAM78D30-595/MB/1500V](https://comparepv.com/compare/shanghai-ja-solar-technology-co-ltd-jam78d30-585-mb-1500v/shanghai-ja-solar-technology-co-ltd-jam78d30-595-mb-1500v) - 3 differences, the largest is module efficiency - [JA Solar JAM78D30-585/MB/1500V vs JA Solar JAM78D30-590/MB/1500V](https://comparepv.com/compare/shanghai-ja-solar-technology-co-ltd-jam78d30-585-mb-1500v/shanghai-ja-solar-technology-co-ltd-jam78d30-590-mb-1500v) - One difference: module efficiency - [JA Solar JAM78D30-585/MB/1500V vs JA Solar JAM78D30-580/MB/1500V](https://comparepv.com/compare/shanghai-ja-solar-technology-co-ltd-jam78d30-585-mb-1500v/shanghai-ja-solar-technology-co-ltd-jam78d30-580-mb-1500v) - One difference: module efficiency - [JA Solar JAM78D30-585/MB/1500V vs JA Solar JAM72D30-580/LB/1500V](https://comparepv.com/compare/shanghai-ja-solar-technology-co-ltd-jam78d30-585-mb-1500v/ja-solar-jam72d30-580-lb-1500v) - 9 differences, the largest is module efficiency - [JA Solar JAM78D30-585/MB/1500V vs JA Solar JAM72D30-575/LB/1500V](https://comparepv.com/compare/shanghai-ja-solar-technology-co-ltd-jam78d30-585-mb-1500v/ja-solar-jam72d30-575-lb-1500v) - 10 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/shanghai-ja-solar-technology-co-ltd-jam78d30-585-mb-1500v/shanghai-ja-solar-technology-co-ltd-jam78d30-605-mb-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.