--- title: "JA Solar JAM72S42-640/LR 640W Solar Panel - Specs & Review | ComparePV" description: "JA Solar JAM72S42-640/LR 640W solar panel. Specs: 22.90% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/ja-solar-jam72s42-640-lr" updated: 2026-09-11 --- # JA Solar JAM72S42-640/LR Light for its output, short guarantee 1,086 panels in the segment TOPCon 600-650 W ## Identity - **Manufacturer:** JA Solar - **Model:** JAM72S42-640/LR - **Series:** JAM72S42 LR - **Rated power:** 640 W - **Cell technology:** TOPCon ## How it compares Compared against segment TOPCon 600-650 W (1086 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 640 W | 620 W | Strong - top 9% | | | Module efficiency | 22.90% | 22.80% | Typical | 2,359 | | Power density | 229.0 | 227.7 | Typical | 2,389 | | Temperature coefficient | -0.290 | -0.290 | Typical | 2,165 | | Weight (kg) | 29.6 kg | 32.7 kg | Strong - top 8% | | | Performance warranty | 25 yrs | 30 yrs | Weak - bottom 3% | 9,798 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 22.90% | 22.80% | Typical | 2,359 | | Power density | 229.0 | 227.7 | Typical | 2,389 | | Temperature coefficient | -0.290 | -0.290 | Typical | 2,165 | | Weight per kWp | 46.2 | 53.1 | Strong - top 8% | 1,092 | | Performance warranty | 25 yrs | 30 yrs | Weak - bottom 3% | 9,798 | ### Strengths - **46.2 kg per kWp** - Top 8% of the TOPCon 600-650 W segment, against a median of 53.1. Ranked 1,092nd in the whole database. ### Watch out for - **25 year performance warranty** - Bottom 3% of the TOPCon 600-650 W segment, against a median of 30 yrs. Ranked 9,798th in the whole database. - **Best for:** Utility-scale, commercial and shaded-installations. - **Not ideal for:** Owners who want a long output guarantee. ## Specification ### Electrical - **Rated power (Pmax):** 640 W - **Efficiency:** 22.90 % - **Voltage at Pmax (Vmp):** 44.29 V - **Current at Pmax (Imp):** 14.45 A - **Open-circuit voltage (Voc):** 52.87 V - **Short-circuit current (Isc):** 15.31 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:** 144 ### Physical - **Length:** 2465 mm - **Width:** 1134 mm - **Thickness:** 30 mm - **Weight:** 29.6 kg - **Area:** 2.80 m2 - **Power density:** 229.0 Wp/m2 ### Warranty and degradation - **Product warranty:** 12 years - **Performance warranty:** 25 years - **Output guaranteed at end of warranty:** 88.4 % - **First-year degradation:** 1.00 % - **Annual degradation:** 0.40 % - **Output after 30 years:** 559 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 2359 of 14005 | | Power density | 2389 of 14005 | | Temperature coefficient | 2165 of 14005 | | Weight | 1092 of 14005 | | Warranty | 9798 of 14005 | ## Pros - **Low N-type TOPCon degradation rate** - TOPCon N-type cells exhibit \<1% first-year degradation and ≤0.40%/year thereafter, compared to ~2% year-1 and ~0.55%/year for legacy PERC modules. Over 25 years of operation the module retains a meaningfully higher share of rated power, directly improving the installation's LCOE. - **625–650 W output cuts BoS costs** - The 625–650 W power range enables a 1 MWp installation with ~1,540 modules instead of ~1,670 at a typical 600 W rating — roughly 8% fewer MC4 connectors, cables, mounting hardware, and labor hours. At utility-scale this translates into a significant balance-of-system cost reduction and a shorter construction schedule. - **BNEF Tier-1 manufacturer — project bankability** - JA Solar has appeared on the BloombergNEF Tier-1 module manufacturer list for multiple consecutive quarters, satisfying the requirement of supplying at least six ≥10 MW projects financed non-recourse by six different banks. This status lowers insurance risk premiums and is a standard prerequisite for financial close of utility-scale PV farms. - **23.3% efficiency matches bifacial peers** - The series peaks at 23.3% module efficiency — identical to the Astronergy ASTRO N5 (bifacial, 23.3%) and marginally above the BYD AURO N NLBK-39 (bifacial, 23.25%). The JAM72S42 LR achieves this as a monofacial module, without the added cost of dual-glass lamination or the ~40% weight penalty associated with bifacial dual-glass construction. ## Cons - **Monofacial in a bifacial-dominated peer group** - All three peer-comparable series (Astronergy ASTRO N5, BYD AURO N NLBK-39, Jinko Solar Tiger Neo 66HL4M-BDX) are bifacial modules. Ground-mounted systems with albedo >0.25 typically gain 10–25% additional energy from rear-side generation. The JAM72S42 LR cannot capture this gain, widening its LCOE disadvantage in utility-scale ground-mount projects relative to direct competitors. - **25-year power warranty vs 30 years from peers** - The BYD AURO N NLBK-39 — at comparable specs (650 W, 23.25%, N-type TOPCon) — carries a 30-year linear power output warranty. The JAM72S42 LR stops at the standard 25-year mark, which may require additional contractual safeguards or module replacement plans in projects with debt tenors exceeding 25 years. - **Efficiency 0.76 pp below Jinko Tiger Neo** - The Jinko Solar Tiger Neo 66HL4M-BDX achieves 24.06% module efficiency at the same 650 W peak power, while the JAM72S42 LR tops out at 23.3%. This 0.76 percentage-point gap translates to roughly 3.3% more roof or land area required per kWp — a meaningful drawback in space-constrained installations. ## About this series JA Solar JAM72S42 LR modules are designed for maximum energy yield from a large working surface area - especially where the cost of energy throughout the entire installation lifecycle is crucial. The application of **N-type monocrystalline cells** translates to highly stable performance over time and reduced susceptibility to efficiency drops, which appeals to investors prioritizing production predictability. The design with **half-cut segmentation** minimizes internal losses and helps maintain higher efficiency even under partial shading or uneven soiling. In practice, the JAM72S42 LR addresses the challenge of limited space in large-scale projects - enabling high-power installations with fewer modules, simplifying logistics and mounting. An additional advantage is **weather resistance**, thanks to a robust junction box and a refined lamination structure. This is the series for PV farms, industrial roofs, and large commercial installations, where **high power density** and long-term reliability are key, rather than marketing fluff. ## Notable figures - At 22.9% efficiency, this panel is on par with typical \*\*TOPCon 600-650W\*\* modules - At 228.9 W/m² power density, roof space requirements are typical for \*\*TOPCon 600-650W\*\* panels - At -0.29%/°C, hot weather performance is typical for \*\*TOPCon 600-650W\*\* panels - 29.6 kg weight - 3.1 kg lighter than \*\*TOPCon 600-650W\*\* median (32.7 kg), reducing installation effort - Ranked #2359 out of 14005 panels for efficiency in the database ## Questions ### What is the warranty on JA Solar JAM72S42 LR panels? The JAM72S42 LR series comes with a 12-year product warranty and a 25-year linear power output warranty. This means the manufacturer guarantees a defined minimum energy yield for a quarter century, which is the standard for Tier 1 modules. As a globally recognized Tier 1 manufacturer, JA Solar provides warranty terms that are critical for projects with long payback horizons. ### What is TOPCon technology and why does the JAM72S42 LR use it? TOPCon (Tunnel Oxide Passivated Contact) is a next-generation N-type cell technology that minimizes carrier recombination at the cell surface. In practice, this translates to module efficiency up to 23.3%, a lower temperature coefficient than PERC cells, and reduced LID degradation in the early years of operation. For investors, this means more predictable and stable energy production over the system's full lifetime. ### Is the JAM72S42 LR a bifacial or monofacial module? The JAM72S42 LR is a monofacial module, meaning energy is generated only through the front cell surface. This approach works well in utility-scale installations and on industrial rooftops where ground albedo is low and bifacial gain would be negligible, making a lower cost per watt the primary driver. ### What is the power output of a JAM72S42 LR panel and how many modules are needed for a 1 MW system? The maximum peak power is 650 Wp. To build a 1 MW installation, you need approximately 1,540 modules from this series. The high unit power simplifies logistics and reduces the number of cable connections and mounting points, which in utility-scale PV projects directly lowers labor and BoS costs. ### Does the JAM72S42 LR perform well under partial shading or variable irradiance? Yes. The half-cut cell design splits each cell into two halves, reducing internal mismatch losses under uneven shading. N-type TOPCon cells also deliver better low-light response compared to legacy PERC modules. In practice, this results in higher energy yield during morning and evening hours and under diffuse cloud cover. ### Is the JAM72S42 LR suitable for industrial rooftops, and what are the module dimensions? Yes, the JAM72S42 LR series is designed for large surface areas: industrial warehouses, manufacturing facilities, and utility-scale PV farms. Module dimensions are approximately 2465 × 1134 × 30 mm with a weight of around 32–33 kg. The large format requires appropriate racking and lifting equipment, but reduces the total module count and number of string connections in the project, lowering overall installation costs. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/16cfa9de032c9aa-d569e71fc400.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | Cooler, +2.3 pp, +5 yr warranty | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | +40 W, +2.3 pp, +5 yr warranty | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | +35 W, +2.1 pp, +5 yr warranty | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | Cooler, +2.1 pp, +5 yr warranty | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | +30 W, +1.9 pp, +5 yr warranty | | [Longi Solar LR7-72HVHF-670M](https://comparepv.com/panel/longi-lr7-72hvhf-670m) | 670 W | +30 W, +1.9 pp, +5 yr warranty | | [AIKO AIKO-A640-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a640-mae72mw) | 640 W | Cooler, +1.9 pp, +5 yr warranty | | [JA Solar JAM78S30-580/MR](https://comparepv.com/panel/ja-solar-jam78s30-580-mr) | 580 W | -60 W, hotter, -2.2 pp | | [JA Solar JAM78S30-585/MR](https://comparepv.com/panel/ja-solar-jam78s30-585-mr) | 585 W | -55 W, hotter, -2.0 pp | | [JA Solar JAM78S30-590/MR](https://comparepv.com/panel/ja-solar-jam78s30-590-mr) | 590 W | -50 W, hotter, -1.8 pp | | [JA Solar JAM78S30-595/MR](https://comparepv.com/panel/ja-solar-jam78s30-595-mr) | 595 W | -45 W, hotter, -1.6 pp | | [JA Solar JAM78S30-600/MR](https://comparepv.com/panel/ja-solar-jam78s30-600-mr) | 600 W | -40 W, hotter, -1.4 pp | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | +60 W, +2.1 pp, +5 yr warranty | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | +55 W, +2.0 pp, +5 yr warranty | | [Jinko Solar JKM650-670N-66QL6-BDV (670W class)](https://comparepv.com/panel/jinko-solar-jkm650-670n-66ql6-bdv-670w-class) | 670 W | +30 W, +1.9 pp, +5 yr warranty | --- Source: https://comparepv.com/panel/ja-solar-jam72s42-640-lr Not in this file, on the page: the I-V and temperature curves lifted from the manufacturer's datasheet, a thirty-year output simulator and alternatives filtered by how closely they match these dimensions.