---
title: "JA Solar vs Just Solar - Brand Comparison | ComparePV"
description: "Compare JA Solar vs Just Solar solar panels: full portfolio, efficiency, cell technology breakdown, warranty terms and company background."
source: "https://comparepv.com/ja-solar-vs-just-solar"
---

# JA Solar vs Just Solar

JA Solar has the broader catalog (504 vs 42 models). JA Solar leads on peak efficiency at 24.80%. JA Solar leans bifacial (47% of lineup).


## The two companies


| Attribute | JA Solar | Just Solar |
| --- | --- | --- |
| Country | China |  |
| Headquarters | Beijing |  |
| Founded | 2005 |  |
| Employees | 37,289 |  |
| Annual capacity | 100+ GW/year |  |
| Tier 1 | yes | no |
| Listed | SZSE: 002459 |  |
| Website | [https://www.jasolar.com](https://www.jasolar.com) |  |

JA Solar is a global leader in the manufacturing of high-performance photovoltaic products. Founded in 2005, the company designs, develops, manufactures, and sells solar cells and modules. JA Solar's products are used in ground-mounted power plants, commercial & industrial rooftop PV systems, and residential rooftop...


## Catalog & Power


| Measure | JA Solar | Just Solar | Margin |
| --- | --- | --- | --- |
| Panel Models | 504 | 42 | +462 |
| Max Power | 740 W | 740 W |  |
| Avg Power | 456 W | 491 W | +34 W |


## Efficiency


| Measure | JA Solar | Just Solar | Margin |
| --- | --- | --- | --- |
| Max Efficiency | 24.80% | 23.82% | +0.98 pp |
| Avg Efficiency | 21.13% | 22.08% | +0.95 pp |


## Reliability & Warranty


| Measure | JA Solar | Just Solar | Margin |
| --- | --- | --- | --- |
| Avg Temp Coefficient | -0.322%/°C | -0.306%/°C | +0.016 |
| Bifacial Share | 238 (47%) | 7 (17%) | +31 pp |
| Avg Warranty | 27.9 yrs | 28.5 yrs | +0.6 yr |


## Efficiency distribution

Just Solar skews to higher efficiency: 33% of lineup is 23%+


| Efficiency band | JA Solar | Just Solar |
| --- | --- | --- |
| \<20% | 112 (22.2%) | 0 |
| 20-21% | 99 (19.6%) | 8 (19.0%) |
| 21-22% | 112 (22.2%) | 14 (33.3%) |
| 22-23% | 107 (21.2%) | 6 (14.3%) |
| 23%+ | 74 (14.7%) | 14 (33.3%) |


## Power distribution

Just Solar offers more 600W+ panels (17% of lineup)


| Power band | JA Solar | Just Solar |
| --- | --- | --- |
| \<400W | 142 (28.2%) | 7 (16.7%) |
| 400-499W | 173 (34.3%) | 21 (50.0%) |
| 500-599W | 120 (23.8%) | 7 (16.7%) |
| 600-699W | 60 (11.9%) | 0 |
| 700W+ | 9 (1.8%) | 7 (16.7%) |


## Cell technology

Dominant cell tech: **PERC** (49%)

Dominant cell tech: **TOPCon** (52%)


| Technology | JA Solar | Just Solar |
| --- | --- | --- |
| PERC | 247 (49.0%) | 0 |
| TOPCon | 146 (29.0%) | 22 (52.4%) |
| N-type | 90 (17.9%) | 0 |
| Unknown | 16 (3.2%) | 0 |
| HJT | 5 (1.0%) | 7 (16.7%) |
| Back Contact | 0 | 13 (31.0%) |


## Top panels, JA Solar


| # | Model | Power | Efficiency | Temp. coefficient | Technology |
| --- | --- | --- | --- | --- | --- |
| 1 | [JAM66D46-740/LB](https://comparepv.com/panel/ja-solar-jam66d46-740-lb) | 740 | 23.8 | -0.290 | Monocrystalline |
| 2 | [JAM66D46-735/LB](https://comparepv.com/panel/ja-solar-jam66d46-735-lb) | 735 | 23.7 | -0.290 | Monocrystalline |
| 3 | [JAM66D46-730/LB](https://comparepv.com/panel/ja-solar-jam66d46-730-lb) | 730 | 23.5 | -0.290 | Monocrystalline |
| 4 | [JAM66D46-725/LB](https://comparepv.com/panel/ja-solar-jam66d46-725-lb) | 725 | 23.3 | -0.290 | Monocrystalline |
| 5 | [JAM66D46-720/LB](https://comparepv.com/panel/ja-solar-jam66d46-720-lb) | 720 | 23.2 | -0.290 | Monocrystalline |
| 6 | [JAM66D46-715/LB](https://comparepv.com/panel/ja-solar-jam66d46-715-lb) | 715 | 23.0 | -0.290 | Monocrystalline |
| 7 | [JAM66D46-710/LB](https://comparepv.com/panel/ja-solar-jam66d46-710-lb) | 710 | 22.9 | -0.290 | Monocrystalline |
| 8 | [JAM66D46-705/LB](https://comparepv.com/panel/ja-solar-jam66d46-705-lb) | 705 | 22.7 | -0.290 | Monocrystalline |
| 9 | [JAM66D46-700/LB](https://comparepv.com/panel/ja-solar-jam66d46-700-lb) | 700 | 22.5 | -0.290 | Monocrystalline |
| 10 | [JAM66D46-695/LB](https://comparepv.com/panel/ja-solar-jam66d46-695-lb) | 695 | 22.4 | -0.290 | Monocrystalline |


## Top panels, Just Solar


| # | Model | Power | Efficiency | Temp. coefficient | Technology |
| --- | --- | --- | --- | --- | --- |
| 1 | [JST-FCMH-740W-HD](https://comparepv.com/panel/just-solar-jst-fcmh-740w-hd) | 740 | 23.8 | -0.260 | Monocrystalline |
| 2 | [JST-FCMH-735W-HD](https://comparepv.com/panel/just-solar-jst-fcmh-735w-hd) | 735 | 23.7 | -0.260 | Monocrystalline |
| 3 | [JST-FCMH-730W-HD](https://comparepv.com/panel/just-solar-jst-fcmh-730w-hd) | 730 | 23.5 | -0.260 | Monocrystalline |
| 4 | [JST-FCMH-725W-HD](https://comparepv.com/panel/just-solar-jst-fcmh-725w-hd) | 725 | 23.3 | -0.260 | Monocrystalline |
| 5 | [JST-FCMH-720W-HD](https://comparepv.com/panel/just-solar-jst-fcmh-720w-hd) | 720 | 23.2 | -0.260 | Monocrystalline |
| 6 | [JST-FCMH-715W-HD](https://comparepv.com/panel/just-solar-jst-fcmh-715w-hd) | 715 | 23.0 | -0.260 | Monocrystalline |
| 7 | [JST-FCMH-710W-HD](https://comparepv.com/panel/just-solar-jst-fcmh-710w-hd) | 710 | 22.9 | -0.260 | Monocrystalline |
| 8 | [JST-EBMH-560W-D](https://comparepv.com/panel/just-solar-jst-ebmh-560w-d) | 560 | 21.9 | -0.360 | Monocrystalline |
| 9 | [JST-EBMH-555W-D](https://comparepv.com/panel/just-solar-jst-ebmh-555w-d) | 555 | 21.7 | -0.360 | Monocrystalline |
| 10 | [JST-EBMH-550W-D](https://comparepv.com/panel/just-solar-jst-ebmh-550w-d) | 550 | 21.5 | -0.360 | Monocrystalline |


## Summary

JA Solar is one of the world's largest solar panel manufacturers, founded in 2005 and headquartered in China, with a workforce of over 37,000 employees and an annual production capacity exceeding 100 GW. Listed on the Shenzhen Stock Exchange (SZSE), the company holds Tier 1 bankable status - confirming the financial solidity and delivery track record required for project financing - and ranks second globally in solar panel shipments. JA Solar has earned "Top Performer" recognition in PVEL's scorecard for ten consecutive years through 2025, underscoring its reliability credentials. Just Solar is a considerably smaller manufacturer based in Shanghai, China, without Tier 1 bankable status. Its portfolio of 42 panel models is modest compared to JA Solar's 524, but the company pursues a focused strategy around next-generation TOPCon cell technology and positions itself as a one-stop solution provider for commercial, industrial, and residential segments worldwide.

JA Solar's portfolio is anchored by PERC technology - over 52% of its modules - supported by an expanding TOPCon and bifacial offering, with bifacial panels representing over 44% of its lineup. An average module power of 441.7 Wp and a maximum efficiency of 24.4% make it a versatile choice across utility-scale ground-mount projects, large commercial and industrial (C&I) installations, and residential rooftop systems where bankability and supply chain depth are decisive factors. Just Solar differentiates itself with a higher average module power of 490.6 Wp and a stronger average efficiency of 22.1%, driven by its TOPCon-first approach (over 52% of its portfolio). A slightly more favorable temperature coefficient (-0.306%/°C vs. -0.323%/°C for JA Solar) and a marginally longer average warranty of 28.5 years add to its appeal for developers prioritising energy density and long-term yield in commercial rooftop or C&I projects.

For most international buyers - particularly those operating within institutional procurement frameworks or requiring project finance - JA Solar's Tier 1 status, independently verified reliability, and vast production scale make it the lower-risk default. Just Solar can be a compelling option for experienced developers or installers willing to accept the non-bankable status in exchange for competitive TOPCon performance figures, but buyers should carefully assess long-term warranty enforcement capacity and supply continuity risks that are inherently higher with a smaller, less established manufacturer.

Written by claude-sonnet from the figures above.


## Other comparisons

- [JA Solar vs A.B. Energy](https://comparepv.com/ja-solar-vs-a-b-energy)
- [AE Solar vs Just Solar](https://comparepv.com/ae-solar-vs-just-solar)
- [JA Solar vs AEET](https://comparepv.com/ja-solar-vs-aeet)
- [AIKO vs Just Solar](https://comparepv.com/aiko-vs-just-solar)
- [JA Solar vs AKCOME](https://comparepv.com/ja-solar-vs-akcome)
- [ARTsolar vs Just Solar](https://comparepv.com/artsolar-vs-just-solar)


---

Source: https://comparepv.com/ja-solar-vs-just-solar

Not in this file, on the page: the distributions above drawn as charts.