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Tongwei Brand review

TWMNH-66HD620

620 Wp TOPCon Bifacial 80%
ComparePV verdict

Strong in heat, no clear weak spot

Rank 2,525 of 14,005
Compare panels Datasheet PDF
Power (Wp)
620
Typical for its class
Efficiency (%)
23.00
Typical · median 22.80%
Density (Wp/m²)
229.5
Typical · median 227.7
Temp (%/°C)
-0.280
Strong · top 7%
Weight (kg)
32.5
Typical · median 32.7 kg
Warranty (yrs)
30
Typical · median 30 yrs

The Tongwei TWMNH (66HD) panel series introduces a new quality to the PV sector, based on innovative N-type cell architecture. The use of TOPCon technology allows for significantly higher conversion efficiency, which directly solves the problem of limited installation space while meeting high power demands. These modules stand out with their bifacial double-glass design, which provides not only additional energy yield from the rear of the cell but, primarily, the highest resistance to demanding external factors such as ammonia or salt mist. Unlike standard products, the TWMNH series guarantees exceptionally low power degradation over the long term, translating into a more stable return on investment for owners of solar farms and large industrial facilities. A key technological element is the SMBB busbar system, which optimizes electron flow and increases the resistance of the cells to mechanical loads caused by snow or strong wind. This solution is dedicated to investors who prioritize durability and strive to achieve the lowest LCOE. Thanks to the optimization of the 66HD format, these panels offer an ideal balance between dimensions and yield, outperforming the competition in terms of stability at high temperatures, making them the most effective choice for modern solar energy in Poland.

Ranking

1,086 panels in the segment TOPCon 600-650 W
Metric This panel Median Position in segment Overall rank
Module efficiency 23.00% 22.80% Typical 1,919
Power density 229.5 227.7 Typical 2,191
Temperature coefficient -0.280 -0.290 Strong · top 7% 1,309
Weight per kWp 52.4 53.1 Typical 5,893
Performance warranty 30 yrs 30 yrs Typical 21
Colour key Strong - top 25% Typical - middle 50% Weak - bottom 25%

Price offers

2 from shops we track
Shop Country Price Per kWp Stock Offer updated Link to shop
pvshop.eu Germany 99.43 € net 160.37 €/kWp In stock 7h ago Visit shop
AZ Solar Shop Italy - - Not stated 7h ago Visit shop

Signals from the data

1 positive · 0 caution
Best for

Utility-scale, commercial and hot-climate.

Strengths
-0.280 %/°C temperature coefficient

Top 7% of the TOPCon 600-650 W segment, against a median of -0.290. Ranked 1,309th in the whole database.

Notes from the database
  • At 23.0% efficiency, this panel is on par with typical TOPCon 600-650W modules
  • Power density of 229.5 W/m² matches the TOPCon 600-650W median
  • At -0.28%/°C, hot weather performance is typical for TOPCon 600-650W panels
  • Bifacial design (80% factor) captures reflected light - adds 4-12% yield on ground-mount or white roof
  • In the top 14% for efficiency among all TOPCon panels

Specifications

Open datasheet PDF
Nominal power (Pmax) 620 Wp Nameplate at 1000 W/m², 25 °C
Module efficiency 23.00 % Typical Segment median 22.80%
Vmpp · Impp 40.82 V · 15.19 A Operating point at max power
Voc · Isc 49.10 V · 16.06 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 32.5 kg Typical Typical · median 32.7 kg
Cells 132 · TOPCon Monocrystalline
Bifaciality 80 % Rear output as a share of front
Coefficient Pmax -0.280 %/°C Strong top 7% of its segment
Coefficient Voc · Isc -0.240 · 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 542 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 620 Wp appear here. The rest cover the 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-66HD620 620 W 23.00% -0.280 32.5 kg You are here
AIKO-A650-MAE72Mw 650 W 25.20% -0.260 27.0 kg +30 W, lighter, +2.2 pp
AIKO-A645-MAE72Mw 645 W 25.00% -0.260 27.0 kg +25 W, lighter, +2.0 pp
AIKO-G670-MCH72Mw 670 W 24.80% -0.260 28.2 kg +50 W, lighter, +1.8 pp
LR7-72HVHF-670M 670 W 24.80% -0.260 28.5 kg +50 W, lighter, +1.8 pp
AIKO-A640-MAE72Mw 640 W 24.80% -0.260 27.0 kg Cooler, lighter, +1.8 pp
JKM650-670N-66QL6-BDV (670W class) 670 W 24.80% -0.260 32.5 kg +50 W, cooler, +1.8 pp
TWMNH-48HC 450 W 16.66% -0.280 29.0 kg -170 W, lighter, -6.3 pp
TWMNH-54HD 515 W 19.07% -0.280 29.0 kg -105 W, lighter, -3.9 pp
TWMNH-66HD600 600 W 22.20% -0.280 32.5 kg -20 W, -0.8 pp
TWMNH-66HD605 605 W 22.40% -0.280 32.5 kg -15 W, -0.6 pp
TWMNH-66HD610 610 W 22.60% -0.280 32.5 kg -10 W, -0.4 pp
TWMNH-66HD615 615 W 22.80% -0.280 32.5 kg Very close match
AIKO-A680-MDE72Mw 680 W 25.20% -0.260 29.0 kg +60 W, lighter, +2.2 pp
AIKO-A675-MDE72Mw 675 W 25.00% -0.260 29.0 kg +55 W, lighter, +2.0 pp
AIKO-A700-MAE78Dw 700 W 25.00% -0.260 34.5 kg +80 W, cooler, +2.0 pp
AIKO-A695-MAE78Dw 695 W 24.90% -0.260 34.5 kg +75 W, cooler, +1.9 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 TOPCon cell technology used in Tongwei TWMNH (66HD) panels and how does it differ from PERC?
TOPCon is an N-type cell technology with an additional tunnel oxide passivation layer that reduces electron recombination and raises conversion efficiency compared to older PERC cells. In practice this means higher power output from the same panel area (up to 630 Wp), better performance at high temperatures, and lower annual degradation. For investors this translates into fewer modules needed to reach the target installed capacity.
What does the double-glass bifacial design of the TWMNH 66HD panels offer?
The dual-glass construction and active rear side allow extra energy yield from reflected light, especially on bright surfaces such as gravel, white roofing, or snow, potentially boosting output by several to over a dozen percent. The double-glass design is also far more resistant to ammonia, salt mist, and humidity than a standard backsheet panel, making it well suited to livestock farms, coastal installations, and large PV farms.
What warranty comes with the Tongwei TWMNH (66HD) series?
The manufacturer offers a 12-year product warranty and a 30-year power performance warranty, guaranteeing 87.4% of nominal power after 30 years of operation. First-year degradation is capped at 1%, followed by roughly 0.4% per year thereafter. Tongwei is a Tier 1 manufacturer, which further reduces the risk of warranty servicing issues over the long term.
What types of installations are Tongwei TWMNH 630 Wp panels best suited for?
Given their dimensions of 2382×1134 mm and weight of 32.5 kg, these panels are primarily intended for large ground-mounted installations, solar farms, and industrial sites where minimizing LCOE per megawatt matters most. The high per-module power output reduces the number of panels, cabling, and mounting structure needed to build an installation of a given capacity.
What is the SMBB busbar system and how does it improve the durability of TWMNH panels?
SMBB (Super Multi Busbar) uses many thin busbars across the cell surface instead of a few wide ones, distributing current more evenly and reducing resistive losses. It also increases cell resistance to microcracks caused by mechanical stress. As a result, TWMNH panels withstand snow loads up to 5400 Pa and wind loads up to 2400 Pa, making them suitable for regions with demanding weather conditions.
How fast does the power output of Tongwei TWMNH panels decline over time?
The panels feature low linear degradation: up to 1% power loss in the first year, followed by roughly 0.4% annually thereafter. After 30 years of operation the manufacturer guarantees at least 87.4% of initial power output. This rate outperforms standard P-type cell panels, resulting in more stable and predictable revenue from the installation over its full service life.
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