--- title: "JA Solar JAM78D40-605/MB/1500V vs JA Solar JAM78D40-615/MB/1500V - Solar Panel Comparison | ComparePV" description: "Compare JA Solar JAM78D40-605/MB/1500V vs JA Solar JAM78D40-615/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-jam78d40-605-mb-1500v/ja-solar-jam78d40-615-mb-1500v" updated: 2026-09-11 --- # JA Solar JAM78D40-605/MB/1500V vs JA Solar JAM78D40-615/MB/1500V 615/MB/1500V leads on the differences that matter The largest is module efficiency: 0.40 pp more efficient. 16 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [JA Solar JAM78D40-605/MB/1500V](https://comparepv.com/panel/ja-solar-jam78d40-605-mb-1500v) | [JA Solar JAM78D40-615/MB/1500V](https://comparepv.com/panel/ja-solar-jam78d40-615-mb-1500v) | | Manufacturer | JA Solar | JA Solar | | Power | 605 Wp | 615 Wp | | Efficiency | 21.60 % | 22.00 % | | Technology | N-type | N-type | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 605/MB/1500V | 615/MB/1500V | Difference | | --- | --- | --- | --- | | Module efficiency | 21.60 % | 22.00 % | +0.40 pp for 615/MB/1500V | | Power density | 216.4 Wp/m² | 220.0 Wp/m² | +3.6 Wp/m² for 615/MB/1500V | | Rated power | 605 Wp | 615 Wp | +10 W for 615/MB/1500V | ## Every compared parameter | Parameter | 605/MB/1500V | 615/MB/1500V | | --- | --- | --- | | Rated power | 605 Wp | 615 Wp | | Module efficiency | 21.60 % | 22.00 % | | Power density | 216.4 Wp/m² | 220.0 Wp/m² | | Open-circuit voltage | 54.90 V | 55.20 V | | Voltage at max power | 45.80 V | 46.07 V | | Short-circuit current | 14.09 A | 14.23 A | | Current at max power | 13.21 A | 13.35 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 | 57.2 kg/kWp | 56.3 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, 605/MB/1500V:** 20,299 kWh - **Cumulative output, 615/MB/1500V:** 20,634 kWh - **Gap:** 335 kWh ## Output when hot | Condition | Cell temperature | 605/MB/1500V | 615/MB/1500V | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 605 W | 615 W | 100.0% of rated power | | Cool, bright day | 40 °C | 578 W | 587 W | 95.5% of rated power | | Typical summer roof | 55 °C | 551 W | 560 W | 91.0% of rated power | | Hot roof | 70 °C | 523 W | 532 W | 86.5% of rated power | ## Against the whole database | Measure | 605/MB/1500V | 615/MB/1500V | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #7,652 | #6,517 | 14,005 | 615/MB/1500V leads by 1,135 places | | Power density | #7,601 | #6,655 | 14,005 | 615/MB/1500V leads by 946 places | | Heat behaviour | #6,093 | #6,093 | 14,005 | Tied - the same position in the database | | Weight | #11,122 | #10,534 | 14,005 | 615/MB/1500V leads by 588 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #4,679 | #3,865 | 14,005 | 615/MB/1500V leads by 814 places | ## Questions ### Which panel is better: JA Solar JAM78D40-605/MB/1500V or JA Solar JAM78D40-615/MB/1500V? According to our database: **JA Solar JAM78D40-615/MB/1500V** has higher module efficiency (**22.00%** vs **21.60%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of JA Solar JAM78D40-605/MB/1500V and JA Solar JAM78D40-615/MB/1500V? **JA Solar JAM78D40-605/MB/1500V** has a module efficiency of **21.60%**, while **JA Solar JAM78D40-615/MB/1500V** is **22.00%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does JA Solar JAM78D40-605/MB/1500V use vs JA Solar JAM78D40-615/MB/1500V? **JA Solar JAM78D40-605/MB/1500V** uses **N-type** cells; **JA Solar JAM78D40-615/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 JAM78D40-605/MB/1500V and JA Solar JAM78D40-615/MB/1500V? **JA Solar JAM78D40-605/MB/1500V** has a **30 years** power warranty; **JA Solar JAM78D40-615/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 JAM78D40-605/MB/1500V and JA Solar JAM78D40-615/MB/1500V bifacial panels? Both **JA Solar JAM78D40-605/MB/1500V** and **JA Solar JAM78D40-615/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 JAM78D40-605/MB/1500V vs JA Solar JAM78D40-625/MB/1500V](https://comparepv.com/compare/ja-solar-jam78d40-605-mb-1500v/ja-solar-jam78d40-625-mb-1500v) - 3 differences, the largest is module efficiency - [JA Solar JAM78D40-605/MB/1500V vs JA Solar JAM78D40-620/MB/1500V](https://comparepv.com/compare/ja-solar-jam78d40-605-mb-1500v/ja-solar-jam78d40-620-mb-1500v) - 3 differences, the largest is module efficiency - [JA Solar JAM78D40-605/MB/1500V vs JA Solar JAM78D40-610/MB/1500V](https://comparepv.com/compare/ja-solar-jam78d40-605-mb-1500v/ja-solar-jam78d40-610-mb-1500v) - One difference: module efficiency - [JA Solar JAM78D40-605/MB/1500V vs JA Solar JAM78D40-600/MB/1500V](https://comparepv.com/compare/ja-solar-jam78d40-605-mb-1500v/ja-solar-jam78d40-600-mb-1500v) - The same specification on paper - [JA Solar JAM78D40-605/MB/1500V vs JA Solar JAM66D46-740/LB](https://comparepv.com/compare/ja-solar-jam78d40-605-mb-1500v/ja-solar-jam66d46-740-lb) - 14 differences, the largest is module efficiency - [JA Solar JAM78D40-605/MB/1500V vs JA Solar JAM66D46-735/LB](https://comparepv.com/compare/ja-solar-jam78d40-605-mb-1500v/ja-solar-jam66d46-735-lb) - 14 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/ja-solar-jam78d40-605-mb-1500v/ja-solar-jam78d40-615-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.