--- title: "JA Solar JAM66D45-605/LB 605W Solar Panel - Specs & Review | ComparePV" description: "JA Solar JAM66D45-605/LB 605W solar panel. Specs: 22.40% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/ja-solar-jam66d45-605-lb" updated: 2026-09-11 --- # JA Solar JAM66D45-605/LB Middle of its segment, heavy for its output 1,086 panels in the segment TOPCon 600-650 W ## Identity - **Manufacturer:** JA Solar - **Model:** JAM66D45-605/LB - **Series:** DeepBlue 4.0 Pro - **Rated power:** 605 W - **Cell technology:** TOPCon - **Bifacial:** yes ## How it compares Compared against segment TOPCon 600-650 W (1086 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 605 W | 620 W | Weak - bottom 15% | | | Module efficiency | 22.40% | 22.80% | Weak - bottom 23% | 4,774 | | Power density | 224.0 | 227.7 | Weak - bottom 23% | 4,780 | | Temperature coefficient | -0.290 | -0.290 | Typical | 2,165 | | Weight (kg) | 33.1 kg | 32.7 kg | Weak - bottom 21% | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 22.40% | 22.80% | Weak - bottom 23% | 4,774 | | Power density | 224.0 | 227.7 | Weak - bottom 23% | 4,780 | | Temperature coefficient | -0.290 | -0.290 | Typical | 2,165 | | Weight per kWp | 54.7 | 53.1 | Weak - bottom 21% | 9,097 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Watch out for - **54.7 kg per kWp** - Bottom 21% of the TOPCon 600-650 W segment, against a median of 53.1. - **22.40% module efficiency** - Bottom 23% of the TOPCon 600-650 W segment, against a median of 22.80%. - **224.0 watts per square metre** - Bottom 23% of the TOPCon 600-650 W segment, against a median of 227.7. - **Best for:** Commercial, utility-scale and hot-climate. - **Not ideal for:** Weight-limited structures, tight roof space and roofs where every square metre has to count. ## Specification ### Electrical - **Rated power (Pmax):** 605 W - **Efficiency:** 22.40 % - **Voltage at Pmax (Vmp):** 39.60 V - **Current at Pmax (Imp):** 15.28 A - **Open-circuit voltage (Voc):** 47.90 V - **Short-circuit current (Isc):** 16.00 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.290 %/degC - **Temperature coefficient of Voc:** -0.250 %/degC - **Temperature coefficient of Isc:** 0.045 %/degC - **NOCT:** 45 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** TOPCon - **Cell count:** 132 - **Bifacial:** yes ### Physical - **Length:** 2382 mm - **Width:** 1134 mm - **Thickness:** 30 mm - **Weight:** 33.1 kg - **Area:** 2.70 m2 - **Power density:** 224.0 Wp/m2 ### Warranty and degradation - **Product warranty:** 12 years - **Performance warranty:** 30 years - **Output guaranteed at end of warranty:** 87.4 % - **First-year degradation:** 1.00 % - **Annual degradation:** 0.40 % - **Output after 30 years:** 529 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 4774 of 14005 | | Power density | 4780 of 14005 | | Temperature coefficient | 2165 of 14005 | | Weight | 9097 of 14005 | | Warranty | 21 of 14005 | ## About this series The JA Solar DeepBlue 4.0 Pro series is a breakthrough in efficiency, based on advanced **n-type cells in Bycium+ technology**. This solution effectively eliminates light-induced degradation problems, which translates into stable energy production for decades. Thanks to the use of **SMBB technology** and high packing density, these panels offer significantly higher efficiency than standard p-type modules, while maintaining optimal dimensions for easy installation. The innovation of the series is demonstrated by an excellent temperature coefficient, which makes the installation work more efficiently on hot days, generating real savings for the investor. DeepBlue 4.0 Pro is a choice dedicated to **demanding commercial and industrial installations**, where a quick return on investment and maximizing yields from limited roof space are key. A distinguishing factor against the competition is the **optimized module format**, which allows for a reduction in BOS system costs while increasing the installed power. By choosing this series, the user receives a product with the **highest mechanical reliability** and excellent resistance to harsh weather conditions, guaranteeing energy security at the highest level. ## Notable figures - Efficiency of 22.4% matches the \*\*TOPCon 600-650W\*\* median - 224.0 W/m² power density is 3.7 W/m² below \*\*TOPCon 600-650W\*\* median (227.7 W/m²) - requires larger installation area - At -0.29%/°C, hot weather performance is typical for \*\*TOPCon 600-650W\*\* panels - Bifacial design (80% factor) captures reflected light - adds 4-12% yield on ground-mount or white roof - #4774 for efficiency, #2165 for temperature performance out of 14005 panels ## Questions ### What is the warranty on JA Solar DeepBlue 4.0 Pro panels? The DeepBlue 4.0 Pro series comes with a 12-year product warranty covering material and manufacturing defects, and a 30-year power output warranty. After 30 years of operation, the panel is guaranteed to retain at least 87.4% of its nominal power, corresponding to an annual degradation rate of just 0.3%. This is one of the strongest performance guarantees available among n-type modules on the market. ### What is Bycium+ cell technology used in the DeepBlue 4.0 Pro, and is the premium worth it? Bycium+ is JA Solar's proprietary n-type TOPCon cell implementation. Compared to p-type PERC cells, it delivers a lower temperature coefficient (approx. -0.29%/°C), no light-induced degradation (LID), and better low-irradiance performance. In practice this translates to more kilowatt-hours generated annually from the same roof area, accelerating the return on investment compared to conventional PERC modules. ### Are JA Solar DeepBlue 4.0 Pro panels bifacial, and how much extra energy can I expect from the rear side? Yes, the DeepBlue 4.0 Pro is a bifacial dual-glass module. The rear side captures reflected irradiance (albedo), delivering 5–15% additional energy yield depending on the ground surface. The gain is most pronounced over light-colored surfaces such as gravel, light concrete, or snow. For ground-mount and industrial rooftop systems this is a real production boost at no additional module cost. ### How does the DeepBlue 4.0 Pro 630W perform during hot summer days? The TOPCon Bycium+ technology delivers a power temperature coefficient of approximately -0.29%/°C. When a panel heats up to 65°C on a hot day, power loss is around 11.6%, while conventional p-type PERC modules typically lose 13–14% under the same conditions. Over a full year this adds up to measurably higher energy production with no additional investment required. ### Is the JA Solar DeepBlue 4.0 Pro 630W suitable for commercial or industrial flat-roof installations? Yes, the 630W DeepBlue 4.0 Pro variant is designed primarily for large-scale C&I (commercial and industrial) installations. Its high unit power reduces the total module count and lowers Balance of System (BoS) costs. The module withstands snow loads up to 5400 Pa and wind pressure up to 2400 Pa, meeting structural requirements for industrial flat roofs with standard racking systems. ### How does JA Solar DeepBlue 4.0 Pro compare to older p-type PERC panels from the same brand? The fundamental difference is cell technology: DeepBlue 4.0 Pro uses n-type TOPCon (Bycium+) cells, whereas older JA Solar series relied on p-type PERC. N-type eliminates LID degradation, achieves module efficiency above 23%, has a better temperature coefficient, and delivers higher bifacial gain. In real-world terms this means more energy output over the entire system lifetime from a module of comparable physical size. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/25f25cb57ef66-c3351acd5e21.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | +45 W, lighter, +2.8 pp | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | +40 W, lighter, +2.6 pp | | [Longi Solar LR7-60HVH-560M](https://comparepv.com/panel/longi-lr7-60hvh-560m) | 560 W | -45 W, lighter, +2.4 pp | | [AIKO AIKO-A640-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a640-mae72mw) | 640 W | +35 W, lighter, +2.4 pp | | [Longi Solar LR7-60HVH-555M](https://comparepv.com/panel/longi-lr7-60hvh-555m) | 555 W | -50 W, lighter, +2.2 pp | | [AIKO AIKO-A635-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a635-mae72mw) | 635 W | +30 W, lighter, +2.2 pp | | [JA Solar JAM66D45-610/LB](https://comparepv.com/panel/ja-solar-jam66d45-610-lb) | 610 W | +0.2 pp | | [JA Solar JAM66D45-615/LB](https://comparepv.com/panel/ja-solar-jam66d45-615-lb) | 615 W | +10 W, +0.4 pp | | [JA Solar JAM66D45-620/LB](https://comparepv.com/panel/ja-solar-jam66d45-620-lb) | 620 W | +15 W, +0.6 pp | | [JA Solar JAM66D45-625/LB](https://comparepv.com/panel/ja-solar-jam66d45-625-lb) | 625 W | +20 W, +0.7 pp | | [JA Solar JAM66D45-630/LB](https://comparepv.com/panel/ja-solar-jam66d45-630-lb) | 630 W | +25 W, +0.9 pp | | [JA Solar JAM66D45-635/LB](https://comparepv.com/panel/ja-solar-jam66d45-635-lb) | 635 W | +30 W, +1.1 pp | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | +75 W, lighter, +2.8 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | +70 W, lighter, +2.6 pp | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | +95 W, cooler, +2.6 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | +90 W, cooler, +2.5 pp | --- Source: https://comparepv.com/panel/ja-solar-jam66d45-605-lb Not in this file, on the page: the I-V and temperature curves lifted from the manufacturer's datasheet, a thirty-year output simulator, a bifacial gain calculator and alternatives filtered by how closely they match these dimensions.