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JA Solar JAM54D40-475/LB
JA Solar Brand review

JAM54D40-475/LB

475 Wp TOPCon Bifacial 80%
ComparePV verdict

Efficiency leader, no clear weak spot

Rank 5,786 of 14,005
Compare panels Datasheet PDF
Power (Wp)
475
Typical for its class
Efficiency (%)
23.80
Strong · top 3%
Density (Wp/m²)
237.7
Strong · top 3%
Temp (%/°C)
-0.290
Typical · median -0.290
Weight (kg)
22.0
Strong · 2.0 kg below median
Warranty (yrs)
30
Typical · median 30 yrs

JA Solar JAM54D40 LB series modules feature a glass-glass construction designed to genuinely increase energy yield not only from the front side but also from the rear-side reflected light. The key advantage of this series is the combination of N-type cells with the TOPCon architecture and the half-cut cell layout, resulting in better performance under partial shading and more stable energy production in varying conditions. In practice, this translates to reduced losses, higher predictability of energy output, and easier planning for self-consumption.

Thanks to the dual glass design, the panels are more resilient to demanding installation conditions - from flat roofs to ground-mounted systems, carports, and pergolas, where the rear side can additionally contribute to the yield. This makes them an excellent choice for investors seeking maximum energy output from limited space, as well as for commercial projects where the focus is on the energy cost over the lifetime and longevity, not just the nominal power.

Ranking

1,089 panels in the segment TOPCon 450-500 W
Metric This panel Median Position in segment Overall rank
Module efficiency 23.80% 22.52% Strong · top 3% 433
Power density 237.7 225.2 Strong · top 3% 467
Temperature coefficient -0.290 -0.290 Typical 2,165
Weight per kWp 46.3 52.2 Strong · top 16% 1,117
Performance warranty 30 yrs 30 yrs Typical 21
Colour key Strong - top 25% Typical - middle 50% Weak - bottom 25%

Signals from the data

8 positive · 1 caution
Best for

Residential, commercial and shaded-installations.

Strengths
23.80% module efficiency

Top 3% of the TOPCon 450-500 W segment, against a median of 22.52%. Ranked 433rd in the whole database.

237.7 watts per square metre

Top 3% of the TOPCon 450-500 W segment, against a median of 225.2. Ranked 467th in the whole database.

46.3 kg per kWp

Top 16% of the TOPCon 450-500 W segment, against a median of 52.2.

What owners get
N-type TOPCon – lower LID and better thermal performance

N-type cells exhibit LID below 0.5% (vs. ~2% for P-type PERC), with a temperature coefficient of Pmax at -0.29%/°C — among the lowest in the segment. At a typical cell temperature of 50°C, power loss is ~8.7%, versus ~10.5% for PERC modules, translating into measurably higher annual yield in warm climates.

Bifacial glass-glass – rear-side energy gain

The glass-glass construction with an active rear side delivers 5–15% additional energy output depending on ground albedo (white membrane, gravel, concrete). Double glass simultaneously provides superior mechanical resilience: snow load up to 5,400 Pa and wind load 2,400 Pa, making the series suitable for carport, pergola, and large flat-roof installations.

30-year linear power warranty, 87.4% retained after 30 years

The manufacturer guarantees annual degradation of 0.4%/year and at least 87.4% of nameplate power after 30 years of operation. Direct peer comparables — Astronergy ASTRO N7s 2.0 and Longi Hi-MO X10 Explorer — offer identical or equivalent linear power warranty terms, confirming JA Solar's competitive positioning on long-term LCOE.

Bankability: BNEF Tier 1, 100 GW production capacity

JA Solar has maintained BNEF Tier 1 bankable status continuously and reached 100 GW annual production capacity in 2025, placing it among the top global module manufacturers. Tier 1 status is required by most non-recourse project finance lenders, eliminating manufacturer bankability risk in commercial-scale deployments.

Efficiency up to 23.8% – parity with segment leaders

The top variant (475 Wp) achieves 23.8% module efficiency, matching direct peers Astronergy ASTRO N7s 2.0 (23.8%) and Sun Earth TITAN Dual GLASS (23.8%) precisely. This enables maximum energy density on constrained roof areas without the price premium typically associated with HJT technology.

Trade-offs
Product warranty range: 12–15 years across variants

Across the 9 variants in the series, the product warranty spans 12 to 15 years depending on the specific model (BF 15Y suffix vs. base variants). Variants carrying only a 12-year product warranty fall below the 15-year standard offered by Longi Hi-MO X10 Explorer and Astronergy ASTRO N7s 2.0 — buyers should verify the variant designation to avoid lower factory coverage.

Notes from the database
  • Efficiency of 23.8% is 1.3pp above the TOPCon 450-500W median (22.5%)
  • At 237.7 W/m² power density, this panel generates 12.5 W/m² more per unit area than TOPCon 450-500W median (225.2 W/m²)
  • Temperature coefficient of -0.29%/°C matches the TOPCon 450-500W median
  • At 22.0 kg, this panel is 2.0 kg lighter than TOPCon 450-500W median (24.0 kg) - easier handling during installation
  • 80% bifaciality enables rear-side power generation, boosting yield by 4-12% on reflective surfaces

Specifications

Open datasheet PDF
Nominal power (Pmax) 475 Wp Nameplate at 1000 W/m², 25 °C
Module efficiency 23.80 % Strong Segment median 22.52%
Vmpp · Impp 33.68 V · 14.11 A Operating point at max power
Voc · Isc 40.55 V · 16.19 A Sizes the string length
Max system voltage 1500 V Longer strings than 1000 V modules
Dimensions 1762×1134×30 mm · 2.00 m² of roof
Weight 22.0 kg Strong Strong · 2.0 kg below median
Cells 108 · TOPCon Monocrystalline
Bifaciality 80 % Rear output as a share of front
Coefficient Pmax -0.290 %/°C Typical median -0.290 of its segment
Coefficient Voc · Isc -0.250 · 0.045 %/°C
NOCT 45 °C At 800 W/m², 20 °C ambient
Product warranty 15 years Hardware defects only
Performance warranty 30 years Typical median 30 yrs · median 30 yrs
End-of-warranty output 87.4 % Equals 415 W guaranteed
Degradation 1.00 → 0.40 % First year, then annual

Datasheet charts

Open datasheet PDF

Measured curves published by JA Solar in this model's datasheet. A chart carrying a wattage was measured on that variant alone - only the ones that describe 475 Wp appear here. The rest cover the whole series.

Linear Performance Warranty: n-type Bifacial Double Glass Module vs Standard Module Linear Performance Warranty: n-type Bifacial Double Glass Module vs Standard Module Whole series

Simulations

Live - change any input
Lifetime output & value
30 years at 1200 kWh/kWp/year and €0.50 per kWh
Power in year 30
-
Lifetime energy
-
Energy value
-
With bifacial gain
-

Degradation from this panel's own datasheet figures. No inverter, soiling or shading losses.

Heat losses
-0.290 %/°C against a segment median of -0.290
-
Bifacial gain
Rear gain over light concrete: -
-

Model: bifaciality × albedo × 0.6 view factor. A first-order estimate, not a yield simulation.

Filter these
Size
Panel Power Eff. Temp. Weight Difference
JA Solar JAM54D40-475/LB 475 W 23.80% -0.290 22.0 kg You are here
LR7-54HJD-510M 510 W 25.00% -0.240 23.5 kg +35 W, cooler, +1.2 pp
AIKO-A495-MCE54Mw 495 W 24.80% -0.260 21.0 kg +20 W, cooler, +1.0 pp
LR7-54HJD-505M 505 W 24.70% -0.240 23.5 kg +30 W, cooler, +0.9 pp
AIKO-A490-MCE54Mw 490 W 24.50% -0.260 21.0 kg +15 W, cooler, +0.7 pp
LR7-54HJD-500M 500 W 24.50% -0.240 23.5 kg +25 W, cooler, +0.7 pp
CIPRO-TN9C54M-500W 500 W 24.50% -0.260 21.4 kg +25 W, cooler, +0.7 pp
NS-420MH-108 420 W 21.01% -0.290 24.5 kg -55 W, heavier, -2.8 pp
JAM54D41-430/LB 430 W 21.50% -0.290 22.0 kg -45 W, -2.3 pp
JAM54S40-435/LR 435 W 21.80% -0.290 20.0 kg -40 W, lighter, -2.0 pp
JAM54S40-440/LR 440 W 22.00% -0.290 20.0 kg -35 W, lighter, -1.8 pp

Found 1395 panels of the same or similar size to this one, within ±10 mm. See them here Found 1425 panels of the same or similar size to this one, within ±25 mm. See them here Found 3614 panels of the same or similar size to this one, within ±50 mm. See them here Found 3962 panels of the same or similar size to this one, within ±100 mm. See them here

Common questions

6 answered
What does TOPCon N-type cell technology mean in the JA Solar JAM54D40 LB, and how does it compare to PERC?
TOPCon (Tunnel Oxide Passivated Contact) is an N-type cell architecture that delivers lower annual degradation than PERC — approximately 0.4% per year after the first year. This means more energy produced over the full system lifetime. N-type cells are also less susceptible to PID (potential-induced degradation) and perform better at high temperatures, which matters on south-facing rooftops during summer peak production hours.
How much extra energy can I expect from the bifacial design of the JAM54D40 LB modules?
The rear side of the JAM54D40 LB modules captures light reflected from the ground surface — gravel, sand, light-colored roofing membrane, or snow. JA Solar estimates an additional bifacial gain of 5–25% depending on ground albedo and tilt angle. The highest gains are achieved in ground-mount systems and carports with light-colored surfaces where the module's rear face has good exposure to reflected irradiance.
What warranty does the JA Solar JAM54D40 LB series come with, and what does it cover?
The JAM54D40 LB series comes with a 15-year product warranty covering physical defects and workmanship, plus a 30-year linear power performance guarantee. After 30 years of operation the module retains at least 80% of its nominal output, with annual degradation of approx. 0.4%. JA Solar is a Tier 1 manufacturer, meaning the warranty is backed by a financially stable company with global service coverage.
Are the JAM54D40 LB panels suitable for flat-roof installations, carports, or pergolas?
Yes, the JAM54D40 LB series is particularly well suited for these applications. The double-glass construction provides superior mechanical strength and moisture resistance, which is critical for low-tilt or horizontal installations. On flat roofs and pergolas the bifacial rear face can generate additional energy from reflected light. At 1762×1134 mm and approx. 22 kg, the modules are compatible with standard racking and BoS hardware available on the market.
How do JA Solar JAM54D40 LB panels handle partial shading from a chimney or dormer window?
The half-cut cell layout splits each cell into two independent halves, which significantly limits the impact of localized shading on overall module output. When a chimney or dormer covers part of the panel, the unshaded cell halves continue operating without disruption. The TOPCon N-type technology also maintains stable output under diffuse light conditions, improving annual energy yield in climates with frequent overcast days.
What is the maximum power output of the JA Solar JAM54D40 LB, and is this series still available?
The JAM54D40 LB series is active and currently available. The peak power rating reaches up to 475 Wp, delivering module efficiency above 23% at compact dimensions of 1762×1134 mm. This makes it a strong choice both for residential prosumer systems with limited roof space and for commercial installations where low LCOE and long-term durability are the primary selection criteria.
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