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Tongwei TWMNH-66HD645
Tongwei Brand review

TWMNH-66HD645

645 Wp N-type Bifacial 80%
ComparePV verdict

Efficiency leader, no clear weak spot

Rank 1,342 of 14,005
Compare panels Datasheet PDF
Power (Wp)
645
Strong · top 3%
Efficiency (%)
23.90
Strong · top 2%
Density (Wp/m²)
238.8
Strong · top 2%
Temp (%/°C)
-0.280
Strong · top 14%
Weight (kg)
32.2
Typical · median 32.5 kg
Warranty (yrs)
30
Typical · median 30 yrs

Tongwei TWMNH-66HD series are N-type half-cut modules designed for high energy yield in real-world operating conditions - including low irradiance and applications subject to periodic shading. The key advantage lies in combining technologies boosting both-sided gain with solutions enhancing long-term reliability: high bifaciality translates to additional rear-side generation, while ultra-low degradation helps maintain predictable energy production for years. This series also features 908 Technology (0BB), an interconnection architecture minimizing optical losses and improving resistance to micro-cracking, crucial during transport and operation. Furthermore, Stencil Printing and TPE support metallization precision and cell performance quality, contributing to stable parameters. The TWMNH-66HD is ideal for C&I and utility-scale PV farms, where low LCOE, reliability, and maximum yield per square meter matter.

Ranking

359 panels in the segment N-type 600-650 W
Metric This panel Median Position in segment Overall rank
Module efficiency 23.90% 22.77% Strong · top 2% 351
Power density 238.8 227.7 Strong · top 2% 356
Temperature coefficient -0.280 -0.290 Strong · top 14% 1,309
Weight per kWp 49.9 52.7 Typical 3,293
Performance warranty 30 yrs 30 yrs Typical 21
Colour key Strong - top 25% Typical - middle 50% Weak - bottom 25%

Signals from the data

3 positive · 0 caution
Best for

Commercial, utility-scale and shaded-installations.

Strengths
23.90% module efficiency

Top 2% of the N-type 600-650 W segment, against a median of 22.77%. Ranked 351st in the whole database.

238.8 watts per square metre

Top 2% of the N-type 600-650 W segment, against a median of 227.7. Ranked 356th in the whole database.

-0.280 %/°C temperature coefficient

Top 14% of the N-type 600-650 W segment, against a median of -0.290.

Notes from the database
  • Efficiency of 23.9% is 1.1pp above the N-type 600-650W median (22.8%)
  • Power density of 238.8 W/m² packs 11.1 W/m² more into the same footprint vs N-type 600-650W median (227.7 W/m²)
  • Temperature coefficient of -0.28%/°C matches the N-type 600-650W median
  • Bifacial design (80% factor) captures reflected light - adds 4-12% yield on ground-mount or white roof
  • Ranked #351 out of 14005 panels for efficiency in the database

Specifications

Open datasheet PDF
Nominal power (Pmax) 645 Wp Nameplate at 1000 W/m², 25 °C
Module efficiency 23.90 % Strong Segment median 22.77%
Vmpp · Impp 41.51 V · 15.54 A Operating point at max power
Voc · Isc 49.85 V · 16.39 A Sizes the string length
Max system voltage 1500 V Longer strings than 1000 V modules
Dimensions 2382×1134×30 mm · 2.70 m² of roof
Weight 32.2 kg Typical Typical · median 32.5 kg
Cells 132 · N-type Monocrystalline
Bifaciality 80 % Rear output as a share of front
Coefficient Pmax -0.280 %/°C Strong top 14% of its segment
Coefficient Voc · Isc -0.240 · 0.046 %/°C
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 564 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 645 Wp appear here. The rest cover the whole series.

Linear Power Output Warranty Linear Power Output Warranty Whole series Cell temperature 25°C Cell temperature 25°C 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
-0.280 %/°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 TWMNH-66HD645 645 W 23.90% -0.280 32.2 kg You are here
AIKO-A650-MAE72Mw 650 W 25.20% -0.260 27.0 kg Cooler, lighter, +1.3 pp
AIKO-A680-MDE72Mw 680 W 25.20% -0.260 29.0 kg +35 W, lighter, +1.3 pp
AIKO-A675-MDE72Mw 675 W 25.00% -0.260 29.0 kg +30 W, lighter, +1.1 pp
AIKO-A645-MAE72Mw 645 W 25.00% -0.260 27.0 kg Cooler, lighter, +1.1 pp
AIKO-A695-MAE78Dw 695 W 24.90% -0.260 34.5 kg +50 W, heavier, +1.0 pp
AIKO-G670-MCH72Mw 670 W 24.80% -0.260 28.2 kg +25 W, lighter, +0.9 pp
LR7-72HVHF-670M 670 W 24.80% -0.260 28.5 kg +25 W, lighter, +0.9 pp
TWMNH-48HC 450 W 16.66% -0.280 29.0 kg -195 W, lighter, -7.2 pp
TWMNH-54HD 515 W 19.07% -0.280 29.0 kg -130 W, lighter, -4.8 pp
TWMNH-66HD600 600 W 22.20% -0.280 32.5 kg -45 W, -1.7 pp
TWMNH-66HD605 605 W 22.40% -0.280 32.5 kg -40 W, -1.5 pp
TWMNH-66HD610 610 W 22.60% -0.280 32.5 kg -35 W, -1.3 pp
TWMNH-66HD615 615 W 22.80% -0.280 32.5 kg -30 W, -1.1 pp
TWMNH-66HD620 620 W 23.00% -0.280 32.5 kg -25 W, -0.9 pp
AIKO-A700-MAE78Dw 700 W 25.00% -0.260 34.5 kg +55 W, heavier, +1.1 pp
JKM650-670N-66QL6-BDV (670W class) 670 W 24.80% -0.260 32.5 kg +25 W, cooler, +0.9 pp

Found 1119 panels of the same or similar size to this one, within ±10 mm. See them here Found 1125 panels of the same or similar size to this one, within ±25 mm. See them here Found 1236 panels of the same or similar size to this one, within ±50 mm. See them here Found 1917 panels of the same or similar size to this one, within ±100 mm. See them here

Common questions

6 answered
What is the maximum power output of the Tongwei TWMNH-66HD panel and how many cells does it have?
The most powerful variant in the TWMNH-66HD series reaches 655 Wp with efficiency up to 24.2%. The module is built from 132 N-type half-cut cells in a dual-glass configuration, delivering high power density per unit area — important where roof or ground space is limited in C&I projects and PV farms.
What warranty comes with the Tongwei TWMNH-66HD solar panels?
The manufacturer provides a 12-year product warranty and a 30-year power output warranty, guaranteeing 99% of nominal power after the first year and no less than 87.4% after 30 years. Tongwei is a Tier 1 manufacturer headquartered in China, which adds confidence for long-term warranty support.
What is 908 Technology (0BB) used in the TWMNH-66HD, and what benefits does it offer?
908 Technology (0BB) is a busbar-free cell interconnection architecture based on multi-wire bonding. It reduces optical losses caused by busbar shading and improves mechanical resistance to microcracks that can occur during transport, installation, and operation. In practice, this means more stable energy output and lower risk of degradation from cell damage.
How much extra energy does bifaciality add on the TWMNH-66HD, and where does it perform best?
Thanks to high bifaciality, the module generates additional energy from its rear side by capturing light reflected off the ground — the gain depends on the mounting surface's albedo and typically ranges from a few to over a dozen percent of front-side power. This works best on PV farms with light-colored ground or gravel and in ground-mounted C&I installations where the panel is raised above the surface.
Are Tongwei TWMNH-66HD panels suitable for a sloped residential roof?
The TWMNH-66HD is a large module measuring about 2382x1134 mm and weighing around 32 kg, designed primarily for C&I installations and PV farms where maximum yield per square meter and low LCOE matter most. For typical sloped residential roofs, smaller and lighter modules are a better fit, as they're easier to transport and mount on rafters.
How does the TWMNH-66HD perform in high summer temperatures?
The module has a power temperature coefficient of -0.28%/°C, better than many P-type panels, meaning less power loss as cell operating temperature rises above 25°C. In practice, TWMNH-66HD panels lose less efficiency on hot days than older technologies, resulting in higher real-world energy production during summer.
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