Skip to main content
Tongwei Brand review

TWMHF-66HD740X

740 Wp N-type Bifacial 85%
ComparePV verdict

Efficiency leader, no clear weak spot

Rank 130 of 14,005
Compare panels Datasheet PDF
Power (Wp)
740
Strong · top 1%
Efficiency (%)
23.80
Strong · top 1%
Density (Wp/m²)
238.2
Strong · top 1%
Temp (%/°C)
-0.240
Strong · top 3%
Weight (kg)
37.0
Strong · 1.0 kg below median
Warranty (yrs)
30
Typical · median 30 yrs

The Tongwei TWMHF (66HD715-740W) series is designed to deliver maximum yield from every square meter - where power per module and accelerating project completion matter. The application of N-type cells in a half-cut architecture helps reduce resistive losses and better withstand partial shading, translating to a more stable performance in variable weather conditions.

Modules in this series utilize bifacial designs, enabling them to further harness reflected light from the ground - a tangible advantage on flat roofs, PV farms, and structures over light surfaces (e.g., light tiles, light screed). An additional benefit is low annual power degradation over the long term, facilitating energy production planning and improving investment bankability.

TWMHF 66HD is an excellent choice for installers and investors who wish to reduce the number of modules, simplify the logistical mounting, and maintain high string power without compromising reliability.

Ranking

90 panels in the segment N-type 700-750 W
Metric This panel Median Position in segment Overall rank
Module efficiency 23.80% 22.88% Strong · top 1% 433
Power density 238.2 228.6 Strong · top 1% 431
Temperature coefficient -0.240 -0.290 Strong · top 3% 13
Weight per kWp 50.0 53.5 Strong · top 14% 3,317
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
23.80% module efficiency

Top 1% of the N-type 700-750 W segment, against a median of 22.88%. Ranked 433rd in the whole database.

238.2 watts per square metre

Top 1% of the N-type 700-750 W segment, against a median of 228.6. Ranked 431st in the whole database.

-0.240 %/°C temperature coefficient

Top 3% of the N-type 700-750 W segment, against a median of -0.290. Ranked 13th in the whole database.

Notes from the database
  • At 23.8% efficiency, this panel is 0.9pp above typical N-type 700-750W modules (median: 22.9%)
  • Power density of 238.2 W/m² packs 9.6 W/m² more into the same footprint vs N-type 700-750W median (228.6 W/m²)
  • Temperature coefficient of -0.24%/°C vs median -0.29%/°C means ~2% less power loss at 65°C
  • At 37.0 kg, weight matches the N-type 700-750W median
  • Bifacial design (85% factor) captures reflected light - adds 4-13% yield on ground-mount or white roof

Specifications

Open datasheet PDF
Nominal power (Pmax) 740 Wp Nameplate at 1000 W/m², 25 °C
Module efficiency 23.80 % Strong Segment median 22.88%
Vmpp · Impp 42.32 V · 17.49 A Operating point at max power
Voc · Isc 50.62 V · 18.47 A Sizes the string length
Max system voltage 1500 V Longer strings than 1000 V modules
Dimensions 2384×1303×33 mm · 3.11 m² of roof
Weight 37.0 kg Strong Strong · 1.0 kg below median
Cells 132 · N-type Monocrystalline
Bifaciality 85 % Rear output as a share of front
Coefficient Pmax -0.240 %/°C Strong top 3% of its segment
Coefficient Voc · Isc -0.220 · 0.040 %/°C
NOCT 44 °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 88.1 % Equals 652 W guaranteed
Degradation 1.00 → 0.38 % 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 740 Wp appear here. The rest cover the whole series.

Linear Power Output Warranty Linear Power Output Warranty Whole series I-V Curve (Current vs Voltage, Cell temperature 25°C) I-V Curve (Current vs Voltage, 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
-0.240 %/°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 TWMHF-66HD740X 740 W 23.80% -0.240 37.0 kg You are here
AIKO-A700-MAE78Dw 700 W 25.00% -0.260 34.5 kg -40 W, lighter, +1.2 pp
AIKO-A695-MAE78Dw 695 W 24.90% -0.260 34.5 kg -45 W, lighter, +1.1 pp
AIKO-A690-MAE78Dw 690 W 24.70% -0.260 34.5 kg -50 W, lighter, +0.9 pp
AIKO-A790-GRH78Dw 790 W 24.60% -0.260 39.8 kg +50 W, heavier, +0.8 pp
TSM-NEG21C.20Q-760 760 W 24.50% -0.260 38.3 kg +20 W, hotter, +0.7 pp
AIKO-A785-GRH78Dw 785 W 24.40% -0.260 39.8 kg +45 W, heavier, +0.6 pp
GK-4-78HGBD-780M 780 W 24.30% -0.260 38.7 kg +40 W, hotter, +0.5 pp
AIKO-A780-GRH78Dw 780 W 24.30% -0.260 39.8 kg +40 W, heavier, +0.5 pp
JT755SLk(B) 755 W 24.30% -0.240 36.4 kg +15 W, +0.5 pp
TSM-NEG21C.20Q-755 755 W 24.30% -0.260 38.3 kg +15 W, hotter, +0.5 pp
TWMPF-66HD655 655 W 21.10% -0.330 37.9 kg -85 W, hotter, -2.7 pp
TWMPF-66HD660 660 W 21.20% -0.330 37.9 kg -80 W, hotter, -2.6 pp
TWMPF-66HD665 665 W 21.40% -0.330 37.9 kg -75 W, hotter, -2.4 pp
TWMPF-66HD670 670 W 21.60% -0.330 37.9 kg -70 W, hotter, -2.2 pp
TWMPF-66HD675 675 W 21.70% -0.330 37.9 kg -65 W, hotter, -2.1 pp
TWMNF-66HD700XX 700 W 22.50% -0.280 37.9 kg -40 W, hotter, -1.3 pp
AIKO-A805-GRH78Dw 805 W 25.10% -0.260 39.8 kg +65 W, heavier, +1.3 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
What is the maximum efficiency of Tongwei TWMHF 66HD modules and how does it translate to up to 740W output?
TWMHF 66HD modules reach efficiency up to 23.00% thanks to N-type TOPCon cells arranged in a half-cut architecture (132 cells in a 6x22 layout). With dimensions of roughly 2384x1303 mm, this allows a single module to deliver up to 740 Wp, meaning fewer modules are needed to reach a target system power and lower mounting structure and installation labor costs.
How much more energy does a bifacial TWMHF panel produce compared to a standard monofacial module?
Thanks to its bifacial design, the module also generates current from its rear side, capturing light reflected off the ground. Depending on surface albedo (light gravel, white roofing membrane, snow), the real-world energy gain can range from a few to over ten percent compared to a comparable monofacial module - bifaciality of N-type cells is typically higher than that of standard P-type cells.
What warranty comes with Tongwei TWMHF 66HD solar panels?
Tongwei, a Tier 1 manufacturer, provides a 15-year product warranty and a 30-year linear power output warranty on this module. This level of coverage and the manufacturer's reputation make it easier to secure project financing (bankability) and to plan long-term energy production from the system throughout its operating life.
Are TWMHF 66HD panels suitable for large solar farms, or better suited to rooftop installations?
Given the high power output of a single module (up to 740 Wp), a weight of about 38 kg, and dimensions of roughly 2384x1303 mm, the TWMHF 66HD series is primarily designed for large ground-mounted, utility-scale PV plants, where minimizing module count and optimizing string configuration matter most. It also works on large flat roofs, provided the mounting structure and installation logistics are properly planned.
How do TWMHF panels perform in high temperatures and under partial shading?
The module has a power temperature coefficient of -0.30%/°C, meaning a smaller power drop as operating temperature rises compared to typical P-type cells, resulting in higher energy yield in summer. The half-cut architecture further splits cells into smaller segments, reducing the impact of partial shading, such as from chimneys or trees, on overall module output.
Is Tongwei a manufacturer that can be trusted for a large-scale PV investment?
Tongwei is a Chinese, Tier 1-rated manufacturer and one of the world's largest suppliers of solar cells and modules, which translates into supply chain stability and reliable access to warranty service. Tier 1 status is also frequently required by banks and insurers when financing PV projects, making it easier to secure a loan for an installation using TWMHF modules.
Add to compare