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Silfab Brand review

SIL-640 XL

640 Wp N-type Bifacial 80%
ComparePV verdict

Light for its output, no clear weak spot

Rank 650 of 14,005
Compare panels Datasheet PDF
Power (Wp)
640
Strong · top 11%
Efficiency (%)
22.92
Typical · median 22.77%
Density (Wp/m²)
229.2
Typical · median 227.7
Temp (%/°C)
-0.290
Typical · median -0.290
Weight (kg)
29.5
Strong · 3.0 kg below median
Warranty (yrs)
30
Typical · median 30 yrs

The SIL-620/630/640 XL Bifacial series is a lineup of utility-scale modules built for large solar farms where every percentage point of energy yield per hectare matters. The panels are based on N-type cells with NTC technology, whose rear passivation layer reduces charge carrier recombination, delivering higher and more stable performance over time compared to older P-type designs. The use of half-cut cells lowers module operating temperature and minimizes losses caused by shading, which is critical for large installations with uneven irradiance. The dual-sided, bifacial construction captures additional light reflected off the ground, increasing total energy yield without expanding the installation footprint. The panels are manufactured entirely in USA-based factories, which matters for projects subject to local content requirements and Buy American incentive programs. The series also stands out for its high resistance to hail and harsh weather conditions and is backed by one of the industry's longest warranties, 25 years on the product and 30 years on linear power degradation. This is a solution built for investors and EPCs delivering large-scale projects where low LCOE and long-term investment predictability are the top priorities.

Ranking

359 panels in the segment N-type 600-650 W
Metric This panel Median Position in segment Overall rank
Module efficiency 22.92% 22.77% Typical 2,350
Power density 229.2 227.7 Typical 2,379
Temperature coefficient -0.290 -0.290 Typical 2,165
Weight per kWp 46.1 52.7 Strong · top 10% 1,004
Performance warranty 30 yrs 30 yrs Typical 21
Colour key Strong - top 25% Typical - middle 50% Weak - bottom 25%

Signals from the data

1 positive · 0 caution
Best for

Utility-scale and shaded-installations.

Strengths
46.1 kg per kWp

Top 10% of the N-type 600-650 W segment, against a median of 52.7. Ranked 1,004th in the whole database.

Notes from the database
  • At 22.9% efficiency, this panel is on par with typical N-type 600-650W modules
  • Power density of 229.2 W/m² matches the N-type 600-650W median
  • At -0.29%/°C, hot weather performance is typical for N-type 600-650W panels
  • 29.5 kg weight - 3.0 kg lighter than N-type 600-650W median (32.5 kg), reducing installation effort
  • Bifacial design (80% factor) captures reflected light - adds 4-12% yield on ground-mount or white roof

Specifications

Open datasheet PDF
Nominal power (Pmax) 640 Wp Nameplate at 1000 W/m², 25 °C
Module efficiency 22.92 % Typical Segment median 22.77%
Vmpp · Impp 48.78 V · 13.12 A Operating point at max power
Voc · Isc 57.76 V · 13.76 A Sizes the string length
Max system voltage 1500 V Longer strings than 1000 V modules
Dimensions 2465×1133×35 mm · 2.79 m² of roof
Weight 29.5 kg Strong Strong · 3.0 kg below median
Cells 156 · N-type 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 -0.240 · 0.040 %/°C
NOCT 45 °C At 800 W/m², 20 °C ambient
Product warranty 25 years Hardware defects only
Performance warranty 30 years Typical median 30 yrs · median 30 yrs
End-of-warranty output 89.3 % Equals 572 W guaranteed
Degradation 2.00 → 0.30 % First year, then annual

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
Silfab SIL-640 XL 640 W 22.92% -0.290 29.5 kg You are here
AIKO-A650-MAE72Mw 650 W 25.20% -0.260 27.0 kg Cooler, lighter, +2.3 pp
AIKO-A680-MDE72Mw 680 W 25.20% -0.260 29.0 kg +40 W, cooler, +2.3 pp
AIKO-A675-MDE72Mw 675 W 25.00% -0.260 29.0 kg +35 W, cooler, +2.1 pp
AIKO-A645-MAE72Mw 645 W 25.00% -0.260 27.0 kg Cooler, lighter, +2.1 pp
AIKO-G670-MCH72Mw 670 W 24.80% -0.260 28.2 kg +30 W, cooler, +1.9 pp
LR7-72HVHF-670M 670 W 24.80% -0.260 28.5 kg +30 W, cooler, +1.9 pp
AIKO-A640-MAE72Mw 640 W 24.80% -0.260 27.0 kg Cooler, lighter, +1.9 pp
SIL-620 XL 620 W 22.20% -0.290 29.5 kg -20 W, -0.7 pp
SIL-630 XL 630 W 22.56% -0.290 29.5 kg -10 W, -0.4 pp
AIKO-A700-MAE78Dw 700 W 25.00% -0.260 34.5 kg +60 W, heavier, +2.1 pp
AIKO-A695-MAE78Dw 695 W 24.90% -0.260 34.5 kg +55 W, heavier, +2.0 pp
JKM650-670N-66QL6-BDV (670W class) 670 W 24.80% -0.260 32.5 kg +30 W, heavier, +1.9 pp

Found 616 panels of the same or similar size to this one, within ±10 mm. See them here Found 616 panels of the same or similar size to this one, within ±25 mm. See them here Found 616 panels of the same or similar size to this one, within ±50 mm. See them here Found 1813 panels of the same or similar size to this one, within ±100 mm. See them here

Common questions

6 answered
How do the N-type NTC cells in the Silfab SIL-620/630/640 XL panels differ from older P-type panels?
N-type NTC cells feature a rear-side passivation layer that reduces carrier recombination. In practice, this delivers higher efficiency (up to about 23%), lower initial degradation, and more stable energy output over the module's lifetime compared to conventional P-type panels.
How much extra energy does the bifacial design of the Silfab XL Bifacial panels really provide?
The bifacial SIL-620/630/640 XL modules capture additional reflected light on the rear side of the panel. Silfab states that with a highly reflective surface, such as white gravel, rear-side gain can reach up to 90% of nominal power under favorable conditions, though typical utility-scale installations see a more modest single- to low-double-digit percentage boost, without increasing the plant's footprint.
What is the maximum power and efficiency of the Silfab SIL-620/630/640 XL Bifacial modules?
The series ranges from 620 W to 640 Wp, with efficiency reaching close to 23%. The panel measures 2465 x 1133 x 35 mm and weighs about 29.5 kg. The high per-module wattage reduces the number of panels needed to hit a target array capacity, lowering racking and wiring costs on large-scale projects.
What warranty comes with the Silfab NTC XL Bifacial panels, and what does it cover?
Silfab backs the series with a 25-year product warranty and a 30-year linear power warranty. This guarantees a slow, predictable degradation rate year over year, avoiding the step-down losses common in older technologies. For investors and EPCs running utility-scale projects, this is among the longest warranties on the market, simplifying LCOE modeling over multi-decade horizons.
Are the Silfab XL Bifacial panels made in the USA, and does that matter for Buy American programs?
Yes, the SIL-620/630/640 XL Bifacial modules are fully manufactured in Silfab's US factories. This is directly relevant to projects subject to domestic content requirements and Buy American-type incentive programs, including Inflation Reduction Act provisions where component origin affects eligibility for tax credits.
Does the half-cut cell technology in the Silfab XL Bifacial panels actually reduce shading losses?
Yes. Splitting cells into half-cuts lowers the current flowing through each section of the module, reducing power loss from partial shading, for example from passing clouds or soiling across a large array. The design also lowers the module's operating temperature, boosting efficiency on hot, sunny days.
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