Q CELLS Q.TRON BLK M-G11+ 420W vs Tongwei THN-EP08M10 580W

Our Verdict Winner: Q CELLS Q.TRON BLK M-G11+ 420W

The Q CELLS Q.TRON BLK M-G11+ 420W wins this comparison by a clear margin. It offers better long-term durability with 25-year warranty. For most residential installations, the Q CELLS Q.TRON BLK M-G11+ 420W is the stronger choice.

Power / Capacity
420W
vs
580W
Efficiency
21.6%
vs
22.5%
Warranty
25 yrs
vs
12 yrs

Key Differences

  • Q CELLS Q.TRON BLK M-G11+ 420W is rated at 420W while Tongwei THN-EP08M10 580W is rated at 580W, a 160W difference.
  • Tongwei THN-EP08M10 580W achieves 22.5% efficiency vs 21.6% for the other, a 0.9 percentage point gap.
  • Q CELLS Q.TRON BLK M-G11+ 420W comes with a 25-year product warranty vs 12 years for the other.

Specifications Breakdown

Module Efficiency

The Tongwei THN-EP08M10 580W achieves 22.5% module efficiency compared to Q CELLS Q.TRON BLK M-G11+ 420W's 21.6%, meaning Tongwei THN-EP08M10 580W converts 0.9 percentage points more sunlight into electricity per square meter. In practical terms, the Q CELLS Q.TRON BLK M-G11+ 420W produces 215.1 watts per square meter of panel area while the Tongwei THN-EP08M10 580W produces 224.5 W/m². For rooftop installations where space is limited, this efficiency gap determines how many kilowatts you can fit on your available roof area. Over a 25-year system life, even a small efficiency advantage compounds into meaningful additional energy production.

Power Output

The Tongwei THN-EP08M10 580W delivers 580W per panel versus 420W for the Q CELLS Q.TRON BLK M-G11+ 420W, a 160W difference per module. To build an 8 kW residential system, you would need 20 Q CELLS Q.TRON BLK M-G11+ 420W panels or 14 Tongwei THN-EP08M10 580W panels. Choosing the higher-wattage option saves 6 panels, reducing total racking hardware, wiring, and installation labor costs. Higher wattage per panel is particularly valuable for commercial-scale installations where panel count directly impacts balance-of-system costs.

Temperature Coefficient

Both panels share an identical temperature coefficient of -0.29%/°C, meaning they lose power at the same rate as cell temperature rises above the 25°C standard test baseline. At 65°C cell temperature, both retain 94.2% of rated power. Neither panel has a thermal performance advantage, which makes this specification a non-factor in the comparison.

Warranty Coverage

The Q CELLS Q.TRON BLK M-G11+ 420W is backed by a 25-year product warranty and 25-year performance guarantee, while the Tongwei THN-EP08M10 580W offers 12-year product and 25-year performance coverage. The Q CELLS Q.TRON BLK M-G11+ 420W provides 13 additional years of defect protection, covering manufacturing issues, material failures, and premature performance loss. Based on their published degradation rates (1% first year then 0.4%/year for Q CELLS Q.TRON BLK M-G11+ 420W; 1% first year then 0.4%/year for Tongwei THN-EP08M10 580W), after 25 years the Q CELLS Q.TRON BLK M-G11+ 420W should retain approximately 89.4% of original output versus 89.4% for the Tongwei THN-EP08M10 580W. The end-of-life output levels are closely matched.

Physical Dimensions & Weight

The Q CELLS Q.TRON BLK M-G11+ 420W measures 1722×1134×30mm and weighs 21 kg, while the Tongwei THN-EP08M10 580W measures 2278×1134×35mm at 28.5 kg. 1.95 m² of panel area for the Q CELLS Q.TRON BLK M-G11+ 420W versus 2.58 m² for the Tongwei THN-EP08M10 580W. The Q CELLS Q.TRON BLK M-G11+ 420W is 7.5 kg lighter per panel, which reduces structural load requirements on the roof and makes handling easier during installation. For a 20-panel system, that is a total weight difference of 150 kg. The more compact Q CELLS Q.TRON BLK M-G11+ 420W may be easier to fit on irregularly shaped or space-limited rooftops.

Specification Comparison

Specification Q CELLS Q.TRON BLK M-G11+ 420W Tongwei THN-EP08M10 580W
Power 420W 580W
Efficiency 21.6% 22.5%
Power Density 20.0 W/sq ft 20.9 W/sq ft
Cell Type TOPCon N-type TOPCon N-type
Bifacial No No
Weight 21 kg 28.5 kg
Temp Coefficient -0.29%/°C -0.29%/°C
Snow Load 5400 Pa 5400 Pa
Wind Load 3600 Pa 2400 Pa
Product Warranty 25 years 12 years
Performance Warranty 25 years 25 years
Degradation (Year 1) 1% 1%
Annual Degradation 0.4% 0.4%
Country South Korea China

5-Dimension Head-to-Head Analysis

1. Efficiency & Power Density

Winner: Tongwei THN-EP08M10 580W

The Tongwei THN-EP08M10 580W achieves 22.5% efficiency versus 21.6% — a 0.9 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 4.8 kW more total system capacity, or 22 kWh more annual production in an average US location.

2. Hot Climate Performance

Winner: Tie

Both panels share a temperature coefficient of -0.29%/°C — identical heat tolerance.

3. Durability & Warranty

Winner: Q CELLS Q.TRON BLK M-G11+ 420W

Q CELLS Q.TRON BLK M-G11+ 420W leads with a 25-year product warranty versus 12 years. After 25 years, expect 89.4% vs 89.4% of original output for Q CELLS Q.TRON BLK M-G11+ 420W and Tongwei THN-EP08M10 580W respectively.

4. Power Output

Winner: Tongwei THN-EP08M10 580W

The Tongwei THN-EP08M10 580W delivers 580W versus 420W per panel — 160W more. For an 8 kW system, you need 14 panels with the higher-wattage option versus 20 panels, saving 6 panels and the associated racking and labor costs.

5. Cell Technology

Winner: Tie

Both panels use TOPCon N-type cell technology. No technology advantage for either product.

Q CELLS Q.TRON BLK M-G11+ 420W

The Q.TRON BLK is Q CELLS' flagship all-black N-type panel delivering 420W with a 25-year product warranty and sleek aesthetics.

Pros

  • + 25-year product warranty
  • + Sleek all-black design
  • + N-type TOPCon technology
  • + Excellent reliability rating

Cons

  • - Moderate wattage
  • - South Korean premium pricing
  • - All-black runs slightly warmer
View full Q CELLS Q.TRON BLK M-G11+ 420W specs →

Tongwei THN-EP08M10 580W

Tongwei THN-EP08M10 is a high-output N-type TOPCon panel from one of the world's largest solar cell manufacturers.

Pros

  • + Top cell manufacturer
  • + High 580W output
  • + Competitive pricing
  • + Strong R&D backing

Cons

  • - Limited brand recognition outside China
  • - Standard warranty
  • - Newer to module market
View full Tongwei THN-EP08M10 580W specs →

Choose Q CELLS Q.TRON BLK M-G11+ 420W If...

  • Long-term warranty protection is a top priority and you plan to stay in your home for 25+ years
  • You prefer newer cell technology with a longer performance improvement runway
  • Aesthetics-focused homeowners wanting a reliable, all-black panel with strong warranty.

Choose Tongwei THN-EP08M10 580W If...

  • Your roof space is limited and you need maximum power per panel
  • You want fewer panels to reach your target system size, reducing racking and labor costs
  • You prefer newer cell technology with a longer performance improvement runway
  • Large installations seeking competitive N-type pricing from a cell technology leader.

Our Recommendation

Recommended Q CELLS Q.TRON BLK M-G11+ 420W

We recommend the Q CELLS Q.TRON BLK M-G11+ 420W for most buyers in this comparison. It wins 1 of 5 key dimensions and offers a clear advantage in the metrics that matter most for a solar panel purchase. The Tongwei THN-EP08M10 580W remains a good product, but the Q CELLS Q.TRON BLK M-G11+ 420W delivers better overall value for the majority of installations.

Frequently Asked Questions

Which is better, Q CELLS Q.TRON BLK M-G11+ 420W or Tongwei THN-EP08M10 580W?

The Q CELLS Q.TRON BLK M-G11+ 420W wins this comparison by a clear margin. It offers better long-term durability with 25-year warranty. For most residential installations, the Q CELLS Q.TRON BLK M-G11+ 420W is the stronger choice.

Which panel is more efficient, Q CELLS Q.TRON BLK M-G11+ 420W or Tongwei THN-EP08M10 580W?

The Tongwei THN-EP08M10 580W at 22.5% module efficiency. Higher efficiency means more watts per square foot of roof space, which is critical for space-constrained installations. The difference of 0.9 percentage points translates to approximately 160W per panel under standard test conditions.

Which has a better warranty, Q CELLS Q.TRON BLK M-G11+ 420W or Tongwei THN-EP08M10 580W?

The Q CELLS Q.TRON BLK M-G11+ 420W comes with a 25-year product warranty and 25-year performance guarantee. The Tongwei THN-EP08M10 580W offers 12-year product and 25-year performance warranties. Q CELLS Q.TRON BLK M-G11+ 420W provides 13 additional years of product coverage.

Which panel performs better in hot weather?

The Q CELLS Q.TRON BLK M-G11+ 420W has a temperature coefficient of -0.29%/°C and the Tongwei THN-EP08M10 580W is -0.29%/°C. Both handle heat equally. A lower (less negative) temperature coefficient is better.

How many Q CELLS Q.TRON BLK M-G11+ 420W vs Tongwei THN-EP08M10 580W panels do I need for an 8 kW system?

For an 8 kW system: you need 20 Q CELLS Q.TRON BLK M-G11+ 420W panels (420W each) or 14 Tongwei THN-EP08M10 580W panels (580W each). The Tongwei THN-EP08M10 580W requires fewer panels, saving on racking hardware and installation labor.

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Last updated: February 2026