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Tongwei Brand review

TNC G12-66 Bifacial

705 Wp TOPCon
ComparePV verdict

Strong in heat, needs the roof space

Rank 1,007 of 14,005
Compare panels Datasheet PDF
Power (Wp)
705
Weak · bottom 22%
Efficiency (%)
22.70
Weak · bottom 23%
Density (Wp/m²)
227.0
Weak · bottom 21%
Temp (%/°C)
-0.280
Strong · top 11%
Weight (kg)
37.9
Typical · median 38.0 kg
Warranty (yrs)
30
Typical · median 30 yrs

The Tongwei TNC Series of solar panels redefines performance standards thanks to proprietary N-type cell technology, which significantly reduces energy losses at the atomic level. The use of TNC (Tongwei N-type Cell) technology allows for higher light conversion efficiency compared to conventional TOPCon solutions available on the market. The innovative design based on SMBB multi-busbar cells ensures better current flow and minimizes the risk of harmful micro-cracks, which translates into decades of trouble-free operation for the entire system. These panels effectively eliminate the problem of light-induced degradation, offering exceptional resistance to LID and LeTID phenomena. Thanks to an excellent temperature coefficient, these modules work significantly more efficiently on hot summer days, generating more energy from the same roof area. This is an ideal solution for investors looking for maximum yields in difficult lighting conditions, characteristic of the capricious Polish climate. The Tongwei TNC Series stands out from the competition thanks to full control of the silicon supply chain, guaranteeing the highest material purity and stability of electrical parameters for every module. These products are ideal for both residential micro-installations and demanding commercial projects where the priority is the lowest levelized cost of energy (LCOE).

Ranking

420 panels in the segment TOPCon 700-750 W
Metric This panel Median Position in segment Overall rank
Module efficiency 22.70% 23.00% Weak · bottom 23% 3,307
Power density 227.0 230.2 Weak · bottom 21% 3,361
Temperature coefficient -0.280 -0.290 Strong · top 11% 1,309
Weight per kWp 53.8 52.9 Typical 7,811
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 · 2 caution
Best for

Residential, commercial, utility-scale, shaded-installations and hot-climate.

Not ideal for

Roofs where every square metre has to count and tight roof space.

Strengths
-0.280 %/°C temperature coefficient

Top 11% of the TOPCon 700-750 W segment, against a median of -0.290.

Watch-outs
227.0 watts per square metre

Bottom 21% of the TOPCon 700-750 W segment, against a median of 230.2.

22.70% module efficiency

Bottom 23% of the TOPCon 700-750 W segment, against a median of 23.00%.

Notes from the database
  • Efficiency of 22.7% matches the TOPCon 700-750W median
  • 226.9 W/m² power density is 3.2 W/m² below TOPCon 700-750W median (230.2 W/m²) - requires larger installation area
  • Temperature coefficient of -0.28%/°C matches the TOPCon 700-750W median
  • In the top 24% for efficiency among all TOPCon panels

Specifications

Open datasheet PDF
Nominal power (Pmax) 705 Wp Nameplate at 1000 W/m², 25 °C
Module efficiency 22.70 % Weak Segment median 23.00%
Vmpp · Impp 40.52 V · 17.40 A Operating point at max power
Voc · Isc 48.77 V · 18.40 A Sizes the string length
Dimensions 2384×1303 mm · 3.11 m² of roof
Weight 37.9 kg Typical Typical · median 38.0 kg
Bifaciality 80 % Rear output as a share of front
Coefficient Pmax -0.280 %/°C Strong top 11% of its segment
Coefficient Voc · Isc -0.250 · 0.046 %/°C
NOCT 45 °C At 800 W/m², 20 °C ambient
Product warranty 12 years Hardware defects only
Performance warranty 30 years Typical median 30 yrs · median 30 yrs
End-of-warranty output 87.4 % Equals 616 W guaranteed
Degradation 1.00 → 0.40 % First year, then annual

Datasheet charts

Open datasheet PDF

Measured curves published by Tongwei in this model's datasheet. A chart carrying a wattage was measured on that variant alone - only the ones that describe 705 Wp appear here. The rest cover the whole series.

Linear Warranty – Degradation: 1% for 1st year, 0.40%/year from 2~30 years Linear Warranty – Degradation: 1% for 1st year, 0.40%/year from 2~30 years Whole series Current-Voltage Curve (TWMNF-66HD705) Current-Voltage Curve (TWMNF-66HD705) 705 W Power-Voltage Curve (TWMNF-66HD705) Power-Voltage Curve (TWMNF-66HD705) 705 W

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
-0.280 %/°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
Tongwei TNC G12-66 Bifacial 705 W 22.70% -0.280 37.9 kg You are here
AIKO-A680-MDE72Mw 680 W 25.20% -0.260 29.0 kg -25 W, lighter, +2.5 pp
AIKO-A675-MDE72Mw 675 W 25.00% -0.260 29.0 kg -30 W, lighter, +2.3 pp
AIKO-A700-MAE78Dw 700 W 25.00% -0.260 34.5 kg Cooler, lighter, +2.3 pp
AIKO-A695-MAE78Dw 695 W 24.90% -0.260 34.5 kg Cooler, lighter, +2.2 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
JKM650-670N-66QL6-BDV (670W class) 670 W 24.80% -0.260 32.5 kg -35 W, lighter, +2.1 pp
TWMPF-66HD655 655 W 21.10% -0.330 37.9 kg -50 W, hotter, -1.6 pp
TWMPF-66HD660 660 W 21.20% -0.330 37.9 kg -45 W, hotter, -1.5 pp
TWMPF-66HD665 665 W 21.40% -0.330 37.9 kg -40 W, hotter, -1.3 pp
TWMPF-66HD670 670 W 21.60% -0.330 37.9 kg -35 W, hotter, -1.1 pp
TWMPF-66HD675 675 W 21.70% -0.330 37.9 kg -30 W, hotter, -1.0 pp
TWMNF-66HD700XX 700 W 22.50% -0.280 37.9 kg Very close match
AIKO-A805-GRH78Dw 805 W 25.10% -0.260 39.8 kg +100 W, cooler, +2.4 pp
AIKO-A800-GRH78Dw 800 W 24.90% -0.260 39.8 kg +95 W, cooler, +2.2 pp
AIKO-A795-GRH78Dw 795 W 24.80% -0.260 39.8 kg +90 W, cooler, +2.1 pp

Found 1390 panels of the same or similar size to this one, within ±10 mm. See them here Found 1400 panels of the same or similar size to this one, within ±25 mm. See them here Found 1400 panels of the same or similar size to this one, within ±50 mm. See them here Found 1432 panels of the same or similar size to this one, within ±100 mm. See them here

Common questions

6 answered
How much power can Tongwei TNC Series panels with 710 Wp output actually generate?
TNC Series panels reach a maximum output of up to 710 Wp thanks to N-type TOPCon cell technology, delivering higher conversion efficiency on the same surface area compared to classic PERC modules. For a typical 6 kWp residential installation, about 8-9 panels are needed, meaningfully reducing the required roof area while keeping the same system capacity.
What warranty comes with Tongwei TNC Series panels?
Tongwei provides a 12-year product warranty and a 30-year linear power output warranty. This covers both manufacturing defects and excessive efficiency loss over time. Tongwei holds Tier 1 manufacturer status, confirming financial stability and a realistic ability to honor warranty claims throughout this entire period.
Do TNC Series panels perform well on hot summer days?
Yes, TNC Series modules feature a favorable temperature coefficient typical of TOPCon technology, limiting power loss at high cell operating temperatures compared to older PERC-based solutions. In practice, this means smaller efficiency drops on hot summer days, when a roof-mounted panel's temperature can significantly exceed ambient temperature.
How does the N-type TOPCon technology in TNC Series differ from standard PERC panels?
The N-type cells used in TNC Series have a purer silicon structure and an additional passivation layer, reducing carrier recombination and energy losses compared to classic P-type PERC cells. The result is higher module efficiency, lower light-induced degradation, and better resistance to LID and LeTID, translating into more stable energy yields throughout the system's lifetime.
Are Tongwei TNC Series panels resistant to microcracks and mechanical damage?
Yes, the design based on multi-busbar SMBB cells spreads current across more connection paths, reducing the risk of microcracks and limiting the impact of a single cell defect on overall panel performance. This construction improves the module's mechanical durability, which matters both during transport and installation and over years of exposure to snow and wind loads on the roof.
Is the Tongwei TNC Series a bifacial panel?
No, this configuration of the TNC Series is a monofacial panel, not bifacial. It generates energy only from irradiance hitting the front side of the module. Customers looking for extra energy gain from light reflected off the ground can ask Tongwei about separate bifacial variants offered in other product series, so it's worth checking availability when placing an order.
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