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Suntech STP635S-C78/Nsh+
Suntech Brand review

STP635S-C78/Nsh+

635 Wp TOPCon Bifacial 80%
ComparePV verdict

Middle of its segment, heavy for its output

Rank 1,957 of 14,129
Compare panels Datasheet PDF
Power (Wp)
635
Strong · top 16%
Efficiency (%)
22.70
Typical · median 22.80%
Density (Wp/m²)
227.2
Typical · median 227.7
Temp (%/°C)
-0.290
Typical · median -0.290
Weight (kg)
34.7
Weak · 1.9 kg above median
Warranty (yrs)
30
Typical · median 30 yrs

The Suntech Ultra T 1.0 series is a photovoltaic module lineup engineered for investors seeking maximum energy yield from limited installation space. The panels use N-type TOPCon half-cut cells, delivering higher conversion efficiency and reduced power losses from shading effects and resistance. Thanks to multi busbar technology, current collection and optical utilization across the cell surface are improved, resulting in more stable energy output across varying irradiance conditions. Ultra T 1.0 modules are bifacial, double-glass panels, generating additional energy from reflected light hitting the rear side - a solution particularly attractive for utility-scale solar farms and installations on bright, reflective surfaces, where it meaningfully lowers the project's LCOE. The series also stands out for its very low power degradation, achieved through zero LID and reduced LeTID and PID effects, ensuring stable energy production over decades. The reinforced aluminum frame construction provides high resistance to mechanical loads from snow and wind, making this series a solid choice for both rooftop and ground-mounted installations in demanding climate conditions.

Ranking

1,085 panels in the segment TOPCon 600-650 W
Metric This panel Median Position in segment Overall rank
Module efficiency 22.70% 22.80% Typical 3,364
Power density 227.2 227.7 Typical 3,309
Temperature coefficient -0.290 -0.290 Typical 2,220
Weight per kWp 54.6 53.1 Weak · bottom 21% 9,102
Performance warranty 30 yrs 30 yrs Typical 21
Colour key Strong - top 25% Typical - middle 50% Weak - bottom 25%

Signals from the data

0 positive · 1 caution
Best for

Utility-scale, commercial and shaded-installations.

Not ideal for

Weight-limited structures.

Watch-outs
54.6 kg per kWp

Bottom 21% of the TOPCon 600-650 W segment, against a median of 53.1.

Notes from the database
  • Efficiency of 22.7% matches the TOPCon 600-650W median
  • At 227.2 W/m² power density, roof space requirements are typical for TOPCon 600-650W panels
  • Temperature coefficient of -0.29%/°C matches the TOPCon 600-650W median
  • At 34.7 kg, this panel is 1.9 kg heavier than the TOPCon 600-650W median (32.8 kg) - more demanding for installation crews
  • Bifaciality factor of 80% can add 4-12% extra yield with reflective mounting surface

Specifications

Open datasheet PDF
Nominal power (Pmax) 635 Wp Nameplate at 1000 W/m², 25 °C
Module efficiency 22.70 % Typical Segment median 22.80%
Vmpp · Impp 46.06 V · 13.79 A Operating point at max power
Voc · Isc 56.03 V · 14.47 A Sizes the string length
Max system voltage 1500 V Longer strings than 1000 V modules
Dimensions 2465×1134×30 mm · 2.80 m² of roof
Weight 34.7 kg Weak Weak · 1.9 kg above median
Cells 156 · 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 · 0.046 %/°C
NOCT 42 °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 555 W guaranteed
Degradation 1.00 → 0.40 % First year, then annual

Datasheet charts

Open datasheet PDF

Measured curves published by Suntech in this model's datasheet. A chart carrying a wattage was measured on that variant alone - only the ones that describe 635 Wp appear here. The rest cover the whole series.

Current-Voltage (I-V) and Power-Voltage (P-V) Curves Current-Voltage (I-V) and Power-Voltage (P-V) Curves 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
Suntech STP635S-C78/Nsh+ 635 W 22.70% -0.290 34.7 kg You are here
AIKO-A650-MAE72Mw 650 W 25.20% -0.260 27.0 kg Cooler, lighter, +2.5 pp
AIKO-A680-MDE72Mw 680 W 25.20% -0.260 29.0 kg +45 W, lighter, +2.5 pp
AIKO-A675-MDE72Mw 675 W 25.00% -0.260 29.0 kg +40 W, lighter, +2.3 pp
AIKO-A645-MAE72Mw 645 W 25.00% -0.260 27.0 kg Cooler, lighter, +2.3 pp
WST-675BKX72-A2 675 W 25.00% -0.260 32.1 kg +40 W, cooler, +2.3 pp
AIKO-G670-MCH72Mw 670 W 24.80% -0.260 28.2 kg +35 W, lighter, +2.1 pp
LR7-72HVHF-670M 670 W 24.80% -0.260 28.5 kg +35 W, lighter, +2.1 pp
STP570S-C78/Pmh+ 570 W 20.40% -0.340 35.5 kg -65 W, hotter, -2.3 pp
STP570S-C78/Pmhg 570 W 20.40% -0.360 31.1 kg -65 W, hotter, -2.3 pp
STP575S-C78/Pmh+ 575 W 20.60% -0.340 35.5 kg -60 W, hotter, -2.1 pp
STP575S-C78/Pmhg 575 W 20.60% -0.360 31.1 kg -60 W, hotter, -2.1 pp
STP580S-C78/Pmh+ 580 W 20.70% -0.340 35.5 kg -55 W, hotter, -2.0 pp
STP580S-C78/Pmhg 580 W 20.80% -0.360 31.1 kg -55 W, hotter, -1.9 pp
STP585S-C78/Pmh+ 585 W 20.90% -0.340 35.1 kg -50 W, hotter, -1.8 pp
AIKO-A700-MAE78Dw 700 W 25.00% -0.260 34.5 kg +65 W, cooler, +2.3 pp
AIKO-A695-MAE78Dw 695 W 24.90% -0.260 34.5 kg +60 W, cooler, +2.2 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 1838 panels of the same or similar size to this one, within ±100 mm. See them here

About the Ultra T series

6 answered

These answers cover the whole series. Where a figure differs, the specification above is this module's own.

How much extra power does the bifacial design of Suntech Ultra T panels actually add?
Ultra T panels use N-type TOPCon cells with a bifaciality factor of up to 85%, significantly higher than conventional PERC modules. This means the rear side, thanks to light reflected off the roof, gravel, or bright ground surfaces, can generate an additional few to over ten percent of energy above the 650 Wp front-side nominal rating. The actual gain depends on ground albedo and mounting height above the surface.
What warranty does Suntech offer on the Ultra T series and what does it cover?
Suntech provides a 15-year product warranty covering material and workmanship defects, plus a 30-year power output warranty guaranteeing a defined percentage of initial power over the module's lifetime. This long power warranty is possible thanks to the elimination of LID and reduced LeTID and PID degradation in the TOPCon cells, resulting in more stable energy yield throughout the system's lifetime.
How does TOPCon technology in Ultra T differ from standard PERC panels?
N-type TOPCon cells used in the Ultra T series have higher conversion efficiency than traditional PERC cells and lower power losses related to the temperature coefficient, meaning better performance during hot summer conditions when module temperature rises. Additionally, N-type technology is less prone to light-induced degradation, so Ultra T panels retain higher power output over the long term compared to equivalent PERC models from the same manufacturer.
Are Suntech Ultra T panels suited for solar farms or better for residential rooftops?
The glass-glass construction and bifacial design of Ultra T modules make the series particularly attractive for ground-mounted installations and solar farms on bright, reflective surfaces, where the extra rear-side yield meaningfully lowers the levelized cost of energy (LCOE). The reinforced aluminum frame with high snow and wind load resistance also makes these panels suitable for sloped and flat roofs on residential and commercial buildings in demanding climates.
Does Suntech's manufacturer status guarantee long-term reliability for an Ultra T investment?
Suntech is a Tier 1 manufacturer headquartered in China, active in the PV market for over two decades and ranked among the largest global solar module suppliers. Tier 1 status reflects financial stability and continuity of production, which matters for honoring long-term warranties, including the 30-year power warranty offered on the Ultra T series, reducing the risk of warranty service issues down the line.
How many 650 Wp Ultra T panels are needed for a 10 kWp installation?
With a unit power of 650 Wp, roughly 15-16 Ultra T panels are needed to reach a 10 kWp system size. Thanks to the high per-panel output, the target system capacity can be achieved with fewer modules than with older, lower-power panels, reducing the number of mounting brackets required and shortening rooftop installation time.
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