--- title: "JA Solar JAM78D40-600/MB/1500V vs JA Solar JAM78D40-605/MB/1500V - Solar Panel Comparison | ComparePV" description: "Compare JA Solar JAM78D40-600/MB/1500V vs JA Solar JAM78D40-605/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/ja-solar-jam78d40-600-mb-1500v/ja-solar-jam78d40-605-mb-1500v" updated: 2026-09-11 --- # JA Solar JAM78D40-600/MB/1500V vs JA Solar JAM78D40-605/MB/1500V Identical on every published parameter All 19 comparable parameters agree. Two records this alike are usually one panel sold under two names, or two bins of the same production line - decide on price and on who you would rather buy from. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [JA Solar JAM78D40-600/MB/1500V](https://comparepv.com/panel/ja-solar-jam78d40-600-mb-1500v) | [JA Solar JAM78D40-605/MB/1500V](https://comparepv.com/panel/ja-solar-jam78d40-605-mb-1500v) | | Manufacturer | JA Solar | JA Solar | | Power | 600 Wp | 605 Wp | | Efficiency | 21.50 % | 21.60 % | | Technology | N-type | N-type | ## Every compared parameter | Parameter | 600/MB/1500V | 605/MB/1500V | | --- | --- | --- | | Rated power | 600 Wp | 605 Wp | | Module efficiency | 21.50 % | 21.60 % | | Power density | 214.6 Wp/m² | 216.4 Wp/m² | | Open-circuit voltage | 54.75 V | 54.90 V | | Voltage at max power | 45.67 V | 45.80 V | | Short-circuit current | 14.02 A | 14.09 A | | Current at max power | 13.14 A | 13.21 A | | Temperature coefficient | -0.300 %/°C | -0.300 %/°C | | Dimensions | 2465x1134x35 mm | 2465x1134x35 mm | | Module area | 2.795 m² | 2.795 m² | | Weight | 34.6 kg | 34.6 kg | | Weight per kWp | 57.7 kg/kWp | 57.2 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.40 %/yr | 0.40 %/yr | | Cell technology | N-type | N-type | | 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 (-0.300 %/°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, 600/MB/1500V:** 20,131 kWh - **Cumulative output, 605/MB/1500V:** 20,299 kWh - **Gap:** 168 kWh ## Output when hot | Condition | Cell temperature | 600/MB/1500V | 605/MB/1500V | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 600 W | 605 W | 100.0% of rated power | | Cool, bright day | 40 °C | 573 W | 578 W | 95.5% of rated power | | Typical summer roof | 55 °C | 546 W | 551 W | 91.0% of rated power | | Hot roof | 70 °C | 519 W | 523 W | 86.5% of rated power | ## Against the whole database | Measure | 600/MB/1500V | 605/MB/1500V | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #7,958 | #7,652 | 14,005 | 605/MB/1500V leads by 306 places | | Power density | #8,200 | #7,601 | 14,005 | 605/MB/1500V leads by 599 places | | Heat behaviour | #6,093 | #6,093 | 14,005 | Tied - the same position in the database | | Weight | #11,358 | #11,122 | 14,005 | 605/MB/1500V leads by 236 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #4,969 | #4,679 | 14,005 | 605/MB/1500V leads by 290 places | ## Questions ### Which panel is better: JA Solar JAM78D40-600/MB/1500V or JA Solar JAM78D40-605/MB/1500V? According to our database: **JA Solar JAM78D40-605/MB/1500V** has higher module efficiency (**21.60%** vs **21.50%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of JA Solar JAM78D40-600/MB/1500V and JA Solar JAM78D40-605/MB/1500V? **JA Solar JAM78D40-600/MB/1500V** has a module efficiency of **21.50%**, while **JA Solar JAM78D40-605/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 JAM78D40-600/MB/1500V use vs JA Solar JAM78D40-605/MB/1500V? **JA Solar JAM78D40-600/MB/1500V** uses **N-type** cells; **JA Solar JAM78D40-605/MB/1500V** uses **N-type**. 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 JAM78D40-600/MB/1500V and JA Solar JAM78D40-605/MB/1500V? **JA Solar JAM78D40-600/MB/1500V** has a **30 years** power warranty; **JA Solar JAM78D40-605/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 JAM78D40-600/MB/1500V and JA Solar JAM78D40-605/MB/1500V bifacial panels? Both **JA Solar JAM78D40-600/MB/1500V** and **JA Solar JAM78D40-605/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 JAM78D40-600/MB/1500V vs JA Solar JAM78D40-625/MB/1500V](https://comparepv.com/compare/ja-solar-jam78d40-600-mb-1500v/ja-solar-jam78d40-625-mb-1500v) - 4 differences, the largest is module efficiency - [JA Solar JAM78D40-600/MB/1500V vs JA Solar JAM78D40-620/MB/1500V](https://comparepv.com/compare/ja-solar-jam78d40-600-mb-1500v/ja-solar-jam78d40-620-mb-1500v) - 3 differences, the largest is module efficiency - [JA Solar JAM78D40-600/MB/1500V vs JA Solar JAM78D40-615/MB/1500V](https://comparepv.com/compare/ja-solar-jam78d40-600-mb-1500v/ja-solar-jam78d40-615-mb-1500v) - 3 differences, the largest is module efficiency - [JA Solar JAM78D40-600/MB/1500V vs JA Solar JAM78D40-610/MB/1500V](https://comparepv.com/compare/ja-solar-jam78d40-600-mb-1500v/ja-solar-jam78d40-610-mb-1500v) - 3 differences, the largest is module efficiency - [JA Solar JAM78D40-600/MB/1500V vs JA Solar JAM66D46-740/LB](https://comparepv.com/compare/ja-solar-jam78d40-600-mb-1500v/ja-solar-jam66d46-740-lb) - 14 differences, the largest is module efficiency - [JA Solar JAM78D40-600/MB/1500V vs JA Solar JAM66D46-735/LB](https://comparepv.com/compare/ja-solar-jam78d40-600-mb-1500v/ja-solar-jam66d46-735-lb) - 14 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/ja-solar-jam78d40-600-mb-1500v/ja-solar-jam78d40-605-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.