Q CELLS Q.TRON BLK M-G11+ 420W vs Panasonic EVPV400H

Our Verdict Winner: Panasonic EVPV400H

The Panasonic EVPV400H wins this comparison by a narrow margin. It offers better long-term durability with 25-year warranty. For most residential installations, the Panasonic EVPV400H is the stronger choice.

Power / Capacity
420W
vs
400W
Efficiency
21.6%
vs
21.2%
Warranty
25 yrs
vs
25 yrs

Key Differences

  • Q CELLS Q.TRON BLK M-G11+ 420W is rated at 420W while Panasonic EVPV400H is rated at 400W, a 20W difference.
  • Q CELLS Q.TRON BLK M-G11+ 420W achieves 21.6% efficiency vs 21.2% for the other, a 0.4 percentage point gap.
  • Both carry matching 25-year product warranties.
  • Panasonic EVPV400H has a superior temperature coefficient of -0.26%/°C vs -0.29%/°C, retaining more power in hot climates.
  • Q CELLS Q.TRON BLK M-G11+ 420W uses TOPCon N-type cells while Panasonic EVPV400H uses HJT (Heterojunction) cells, representing different technology generations.

Specifications Breakdown

Module Efficiency

The Q CELLS Q.TRON BLK M-G11+ 420W achieves 21.6% module efficiency compared to Panasonic EVPV400H's 21.2%, meaning Q CELLS Q.TRON BLK M-G11+ 420W converts 0.4 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 Panasonic EVPV400H produces 204.8 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 Q CELLS Q.TRON BLK M-G11+ 420W delivers 420W per panel versus 400W for the Panasonic EVPV400H, a 20W difference per module. To build an 8 kW residential system, you would need 20 Q CELLS Q.TRON BLK M-G11+ 420W panels or 20 Panasonic EVPV400H panels. Despite the per-panel wattage difference, both require the same number of panels for this system size due to rounding. Higher wattage per panel is particularly valuable for commercial-scale installations where panel count directly impacts balance-of-system costs.

Temperature Coefficient

The Panasonic EVPV400H has a temperature coefficient of -0.26%/°C versus -0.29%/°C for the Q CELLS Q.TRON BLK M-G11+ 420W. On a hot summer day when cell temperature reaches 65°C (40°C above the 25°C STC baseline), the Panasonic EVPV400H retains 94.8% of its rated power while the other retains 94.2%. While the numerical gap is modest, it still accumulates over decades of summer production, especially in southern latitudes with prolonged peak heat hours.

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 Panasonic EVPV400H offers 25-year product and 25-year performance coverage. Both offer identical product warranty duration. Based on their published degradation rates (1% first year then 0.4%/year for Q CELLS Q.TRON BLK M-G11+ 420W; 0.5% first year then 0.35%/year for Panasonic EVPV400H), after 25 years the Q CELLS Q.TRON BLK M-G11+ 420W should retain approximately 89.4% of original output versus 91.1% for the Panasonic EVPV400H. This 1.7 percentage point gap in end-of-life output meaningfully impacts lifetime energy economics.

Physical Dimensions & Weight

The Q CELLS Q.TRON BLK M-G11+ 420W measures 1722×1134×30mm and weighs 21 kg, while the Panasonic EVPV400H measures 1722×1134×30mm at 21 kg. 1.95 m² of panel area for the Q CELLS Q.TRON BLK M-G11+ 420W versus 1.95 m² for the Panasonic EVPV400H. Their weights are closely matched, so neither panel imposes a significantly different structural load on the mounting system. Similar footprints mean both panels fit comparably on standard residential rooftop configurations.

Specification Comparison

Specification Q CELLS Q.TRON BLK M-G11+ 420W Panasonic EVPV400H
Power 420W 400W
Efficiency 21.6% 21.2%
Power Density 20.0 W/sq ft 19.0 W/sq ft
Cell Type TOPCon N-type HJT (Heterojunction)
Bifacial No Yes
Weight 21 kg 21 kg
Temp Coefficient -0.29%/°C -0.26%/°C
Snow Load 5400 Pa 5400 Pa
Wind Load 3600 Pa 2400 Pa
Product Warranty 25 years 25 years
Performance Warranty 25 years 25 years
Degradation (Year 1) 1% 0.5%
Annual Degradation 0.4% 0.35%
Country South Korea Japan

5-Dimension Head-to-Head Analysis

1. Efficiency & Power Density

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

The Q CELLS Q.TRON BLK M-G11+ 420W achieves 21.6% efficiency versus 21.2% — a 0.4 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 0.6 kW more total system capacity, or 3 kWh more annual production in an average US location.

2. Hot Climate Performance

Winner: Panasonic EVPV400H

The Panasonic EVPV400H has a better temperature coefficient of -0.26%/°C versus -0.29%/°C. On a 45°C summer day (20°C above STC), the winner retains 94.8% of rated power versus 94.2%. The difference is modest but accumulates over 25 years of summer production.

3. Durability & Warranty

Winner: Panasonic EVPV400H

Panasonic EVPV400H degrades more slowly at 0.35% per year versus 0.4%. After 25 years, expect 89.4% vs 91.1% of original output for Q CELLS Q.TRON BLK M-G11+ 420W and Panasonic EVPV400H respectively.

4. Power Output

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

The Q CELLS Q.TRON BLK M-G11+ 420W delivers 420W versus 400W per panel — 20W more. For an 8 kW system, you need 20 panels with the higher-wattage option versus 20 panels, saving 0 panels and the associated racking and labor costs.

5. Cell Technology

Winner: Panasonic EVPV400H

The Q CELLS Q.TRON BLK M-G11+ 420W uses TOPCon N-type: TOPCon (Tunnel Oxide Passivated Contact) adds a thin tunnel oxide layer to reduce recombination losses, achieving higher efficiency than PERC while being manufacturable on existing production lines. The Panasonic EVPV400H uses HJT (Heterojunction): HJT (Heterojunction) combines crystalline silicon with amorphous silicon layers, delivering the best temperature coefficient and bifacial gains, but at higher manufacturing cost. HJT (Heterojunction) represents a newer generation technology with a longer performance runway as manufacturing matures.

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 →

Panasonic EVPV400H

DISCONTINUED: Panasonic exited solar manufacturing in 2023. The EVPV400H was Panasonic's standard HJT residential panel, delivering 400W with the brand's signature quality and longevity.

Pros

  • + Panasonic reliability
  • + HJT advantages
  • + Solid 25-year warranty
  • + Good all-round performer

Cons

  • - DISCONTINUED - no longer manufactured
  • - No new units available
  • - No ongoing product support
View full Panasonic EVPV400H specs →

Choose Q CELLS Q.TRON BLK M-G11+ 420W 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
  • Aesthetics-focused homeowners wanting a reliable, all-black panel with strong warranty.

Choose Panasonic EVPV400H If...

  • You live in a hot climate (Arizona, Texas, Florida) where heat performance matters
  • You want maximum output retention over the system's 25-30 year lifespan
  • You prefer newer cell technology with a longer performance improvement runway
  • No longer available for new installations.

Our Recommendation

Recommended Panasonic EVPV400H

Both the Q CELLS Q.TRON BLK M-G11+ 420W and Panasonic EVPV400H are excellent solar panel options, and the margin between them is narrow. The Panasonic EVPV400H wins 3 of 5 comparison dimensions by a slim margin. Your decision may come down to local pricing, installer availability, and which specific performance metrics matter most for your project. Either product is a solid investment.

Frequently Asked Questions

Which is better, Q CELLS Q.TRON BLK M-G11+ 420W or Panasonic EVPV400H?

The Panasonic EVPV400H wins this comparison by a narrow margin. It offers better long-term durability with 25-year warranty. For most residential installations, the Panasonic EVPV400H is the stronger choice.

Which panel is more efficient, Q CELLS Q.TRON BLK M-G11+ 420W or Panasonic EVPV400H?

The Q CELLS Q.TRON BLK M-G11+ 420W at 21.6% module efficiency. Higher efficiency means more watts per square foot of roof space, which is critical for space-constrained installations. The difference of 0.4 percentage points translates to approximately 20W per panel under standard test conditions.

Which has a better warranty, Q CELLS Q.TRON BLK M-G11+ 420W or Panasonic EVPV400H?

The Q CELLS Q.TRON BLK M-G11+ 420W comes with a 25-year product warranty and 25-year performance guarantee. The Panasonic EVPV400H offers 25-year product and 25-year performance warranties. Both offer identical warranty terms.

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 Panasonic EVPV400H is -0.26%/°C. Panasonic EVPV400H retains more power in heat — important in states like Arizona, Texas, and Florida. A lower (less negative) temperature coefficient is better.

How many Q CELLS Q.TRON BLK M-G11+ 420W vs Panasonic EVPV400H 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 20 Panasonic EVPV400H panels (400W each). The Q CELLS Q.TRON BLK M-G11+ 420W requires fewer panels, saving on racking hardware and installation labor.

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Last updated: February 2026