---
title: "JA Solar JAM66D45-635/LB Solar Panel: Specs & Prices | ComparePV"
description: "JA Solar JAM66D45-635/LB solar panel: 1 shop offer from 106.48 €. Specs: 23.50% efficiency, Monocrystalline cells."
source: "https://comparepv.com/panel/ja-solar-jam66d45-635-lb"
image: "https://comparepv.com/og/panel/ja-solar-jam66d45-635-lb.png"
updated: 2026-10-28
---

# JA Solar JAM66D45-635/LB

Space saver, no clear weak spot

1,085 panels in the segment TOPCon 600-650 W


## Identity

- **Manufacturer:** JA Solar
- **Model:** JAM66D45-635/LB
- **Series:** JAM66D45 LB
- **Rated power:** 635 W
- **Cell technology:** TOPCon
- **Bifacial:** yes


## Price offers

Prices are the figure each shop printed, on that shop's side of VAT.


| Shop | Market | Price | Per kWp | Availability | Last read |
| --- | --- | --- | --- | --- | --- |
| [tienda-solar.es](https://comparepv.com/go/192120) | Spain | 106.48 € incl. VAT | 167.68 €/kWp | In stock | Last read 28 Oct 03:29 |


## How it compares

Compared against segment TOPCon 600-650 W (1085 panels).


| Measure | This panel | Segment median | Standing | Rank |
| --- | --- | --- | --- | --- |
| Power (Wp) | 635 W | 620 W | Strong - top 16% |  |
| Module efficiency | 23.50% | 22.80% | Strong - top 10% | 749 |
| Power density | 235.1 | 227.7 | Strong - top 9% | 777 |
| Temperature coefficient | -0.290 | -0.290 | Typical | 2,220 |
| Weight (kg) | 33.1 kg | 32.8 kg | Typical |  |
| Performance warranty | 30 yrs | 30 yrs | Typical | 21 |


### Full peer table


| Measure | This panel | Segment median | Standing | Rank |
| --- | --- | --- | --- | --- |
| Module efficiency | 23.50% | 22.80% | Strong - top 10% | 749 |
| Power density | 235.1 | 227.7 | Strong - top 9% | 777 |
| Temperature coefficient | -0.290 | -0.290 | Typical | 2,220 |
| Weight per kWp | 52.1 | 53.1 | Typical | 5,640 |
| Performance warranty | 30 yrs | 30 yrs | Typical | 21 |


### Strengths

- **235.1 watts per square metre** - Top 9% of the TOPCon 600-650 W segment, against a median of 227.7. Ranked 777th in the whole database.
- **23.50% module efficiency** - Top 10% of the TOPCon 600-650 W segment, against a median of 22.80%. Ranked 749th in the whole database.

- **Best for:** Commercial, utility-scale and shaded-installations.


## Specification


### Electrical

- **Rated power (Pmax):** 635 W
- **Efficiency:** 23.50 %
- **Voltage at Pmax (Vmp):** 40.99 V
- **Current at Pmax (Imp):** 15.57 A
- **Open-circuit voltage (Voc):** 49.10 V
- **Short-circuit current (Isc):** 16.95 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:** 235.1 Wp/m2


### Warranty and degradation

- **Product warranty:** 12 years
- **Performance warranty:** 30 years
- **Output guaranteed at end of warranty:** 88.4 %
- **First-year degradation:** 1.00 %
- **Annual degradation:** 0.40 %
- **Output after 30 years:** 555 W


## Rank in the whole catalogue


| Measure | Position |
| --- | --- |
| Efficiency | 749 of 14129 |
| Power density | 777 of 14129 |
| Temperature coefficient | 2220 of 14129 |
| Weight | 5640 of 14129 |
| Warranty | 21 of 14129 |


## Pros

- **Up to 24.1% efficiency - peer-group leader** - The JAM66D45 LB series reaches a module efficiency of up to 24.1%, outperforming all direct peer comparables: Astronergy ASTRO N5 (23.3%), BYD AURO N (23.25%), and Jinko Solar Tiger Neo 66HL4M-BDX (24.06%). The margin over the peer-group median is approximately 0.7-0.85 percentage points, directly reducing area requirements and BoS cost per kWp.
- **N-type TOPCon - zero LID, better Tcoeff** - N-type TOPCon cells eliminate Light-Induced Degradation (LID) inherent to P-type PERC. The power temperature coefficient is approximately -0.29%/°C (per ENF/manuals.plus data), versus -0.34 to -0.35%/°C for standard PERC - translating into measurably higher energy yield on hot summer days, especially relevant for C&I rooftop and utility-scale deployments.
- **Bifacial dual-glass - 5-15% additional yield** - A bifaciality factor of ~85% enables 5-15% additional energy harvest from albedo, depending on ground surface (concrete, light gravel). The dual-glass construction (30 mm frame) raises mechanical resistance to 5,400 Pa (snow load) and 2,400 Pa (wind), while the IP68-rated junction box guards against PID-driven humidity degradation across the full 30-year operating life.
- **30-year linear power warranty** - JA Solar guarantees retention of >87% of rated power after 30 years under a linear degradation schedule. This is among the longest warranty horizons available in the bifacial dual-glass 650 W segment and directly improves LCOE for long-duration projects - particularly relevant for non-recourse financed utility-scale PV farms.
- **JA Solar Tier 1 - #1 Wood Mackenzie H1 2025** - JA Solar is listed on the BNEF Tier 1 bankable manufacturers list and ranked first in the Wood Mackenzie Global Solar Module Manufacturer Ranking for H1 2025 with an overall score of 91.7/100. This translates directly into stronger project bankability, lower residual risk for institutional investors, and easier access to non-recourse project financing.


## Cons

- **~33 kg weight - roof structure requirements** - The dual-glass module weighs approximately 33.1 kg versus ~26-28 kg for comparable single-glass modules of similar wattage. Retrofit installations on existing C&I rooftops require structural load assessments on a case-by-case basis, adding engineering costs and potentially limiting applicability on buildings with lightweight steel purlins.


## About this series

JA Solar JAM66D45 LB series modules are designed for installations where maximum energy yield and long-term peace of mind are key considerations - on commercial and industrial rooftops as well as in large PV farms. The use of **N-type TOPCon cells** helps minimize power losses over time and improves performance in demanding conditions, such as high temperatures or lower irradiance. The **bifacial design** allows for utilizing reflected light from the backside, effectively increasing energy production without expanding the installation. Additionally, **double glazing** enhances resistance to atmospheric factors and mechanical stress, which is crucial for investments with a long horizon. From a total cost perspective, this product stands out due to its approach focused on low energy cost in the lifecycle and predictable performance. It is an excellent choice for investors who wish to combine **high reliability proven in tests** with modern technology and the potential for additional gain from the rear side of the module.


## Notable figures

- 23.5% module efficiency - 0.7pp better than the \*\*TOPCon 600-650W\*\* median of 22.8%
- 235.1 W/m² power density - 7.4 W/m² more than \*\*TOPCon 600-650W\*\* median (227.7 W/m²), more power per roof area
- At -0.29%/°C, hot weather performance is typical for \*\*TOPCon 600-650W\*\* panels
- Bifaciality factor of 80% can add 4-12% extra yield with reflective mounting surface
- In the top 5% for efficiency among all TOPCon panels


## Questions


### What warranty does the JA Solar JAM66D45 LB series come with?

The JAM66D45 LB series comes with a 12-year product warranty covering materials and workmanship, plus a 30-year linear power output warranty. After 30 years, the module is guaranteed to retain approximately 83% of its nominal output. This is one of the longer warranty standards available on the market, especially relevant for commercial rooftop and utility-scale investments with long payback horizons.


### What is TOPCon technology and why does the JAM66D45 LB series use it?

TOPCon (Tunnel Oxide Passivated Contact) is an N-type cell technology that uses a thin tunnel oxide layer to minimize carrier recombination at the cell contacts. In practice, this delivers higher module efficiency (up to ~23.3%), a lower temperature coefficient (~-0.29%/°C), and slower power degradation over time compared to PERC cells. The JAM66D45 LB series uses TOPCon specifically to lower the lifetime cost of energy (LCOE) from the installation.


### How do the bifacial JAM66D45 LB panels increase energy production, and when does it make sense?

The JAM66D45 LB modules feature up to 80% bifaciality, meaning the rear side captures light reflected from the surface beneath the array. With a high-albedo ground cover - light gravel, concrete, or snow - this can add roughly 5-15% to energy output compared to a monofacial module of the same nominal power. The actual gain depends on site albedo, tilt angle, and mounting height above ground.


### Is the JAM66D45 LB series suitable for large-scale utility PV farms?

Yes, utility-scale installations are one of the primary use cases for this series. The modules support a 1500 V DC system voltage, simplifying string design and reducing BoS costs. Front snow load resistance of 5,400 Pa and rear wind load of 2,400 Pa make them suitable for demanding locations. The double-glass construction and N-type TOPCon technology ensure predictable production throughout the full investment lifecycle.


### How does the JAM66D45 LB series perform in high-temperature conditions?

The power temperature coefficient for the JAM66D45 LB is approximately -0.29%/°C, meaning the module loses about 2.9% of its rated output for every 10°C rise above 25°C. This outperforms most PERC modules, which typically show around -0.35%/°C. The N-type TOPCon technology helps maintain higher production on hot days - particularly important on dark industrial rooftops with limited airflow.


### What are the dimensions and weight of the JAM66D45 LB module, and is it compatible with standard racking systems?

The JAM66D45 LB module measures 2382 × 1134 × 30 mm and weighs approximately 33.1 kg. This is a commercial and utility-scale format - its size and weight require a properly engineered racking system and appropriate lifting equipment during installation. It is not a standard fit for small residential rooftop systems on typical pitched roofs.


## Datasheet

[Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/cb4feec76c9f3a-965360decfa0.pdf)


## Alternatives


| Panel | Power | How it differs |
| --- | --- | --- |
| [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | Cooler, lighter, +1.7 pp |
| [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | +45 W, lighter, +1.7 pp |
| [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | +40 W, lighter, +1.5 pp |
| [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | Cooler, lighter, +1.5 pp |
| [WINAICO WST-675BKX72-A2](https://comparepv.com/panel/winaico-wst-675bkx72-a2) | 675 W | +40 W, cooler, +1.5 pp |
| [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | +35 W, lighter, +1.3 pp |
| [Longi Solar LR7-72HVHF-670M](https://comparepv.com/panel/longi-lr7-72hvhf-670m) | 670 W | +35 W, lighter, +1.3 pp |
| [JA Solar JAM66D45-605/LB](https://comparepv.com/panel/ja-solar-jam66d45-605-lb) | 605 W | -30 W, -1.1 pp |
| [JA Solar JAM66D45-610/LB](https://comparepv.com/panel/ja-solar-jam66d45-610-lb) | 610 W | -25 W, -0.9 pp |
| [JA Solar JAM66D45-615/LB](https://comparepv.com/panel/ja-solar-jam66d45-615-lb) | 615 W | -20 W, -0.7 pp |
| [JA Solar JAM66D45-620/LB](https://comparepv.com/panel/ja-solar-jam66d45-620-lb) | 620 W | -15 W, -0.5 pp |
| [JA Solar JAM66D45-625/LB](https://comparepv.com/panel/ja-solar-jam66d45-625-lb) | 625 W | -10 W, -0.4 pp |
| [JA Solar JAM66D45-630/LB](https://comparepv.com/panel/ja-solar-jam66d45-630-lb) | 630 W | Very close match |
| [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | +65 W, cooler, +1.5 pp |
| [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | +60 W, cooler, +1.4 pp |
| [Jinko Solar JKM650-670N-66QL6-BDV (670W class)](https://comparepv.com/panel/jinko-solar-jkm650-670n-66ql6-bdv-670w-class) | 670 W | +35 W, cooler, +1.3 pp |


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Source: https://comparepv.com/panel/ja-solar-jam66d45-635-lb

Not in this file, on the page: a thirty-year output simulator, a bifacial gain calculator and alternatives filtered by how closely they match these dimensions.