Maxeon Maxeon 6 425W vs Panasonic EVPV400H

Our Verdict Winner: Maxeon Maxeon 6 425W

The Maxeon Maxeon 6 425W wins this comparison by a decisive margin. It leads in efficiency (22.2% vs 21.2%) and matches or exceeds on warranty (40 vs 25 years). For most residential installations, the Maxeon Maxeon 6 425W is the stronger choice.

Power / Capacity
425W
vs
400W
Efficiency
22.2%
vs
21.2%
Warranty
40 yrs
vs
25 yrs

Key Differences

  • Maxeon Maxeon 6 425W is rated at 425W while Panasonic EVPV400H is rated at 400W, a 25W difference.
  • Maxeon Maxeon 6 425W achieves 22.2% efficiency vs 21.2% for the other, a 1.0 percentage point gap.
  • Maxeon Maxeon 6 425W comes with a 40-year product warranty vs 25 years for the other.
  • Panasonic EVPV400H has a superior temperature coefficient of -0.26%/°C vs -0.27%/°C, retaining more power in hot climates.
  • Maxeon Maxeon 6 425W uses IBC (Interdigitated Back Contact) cells while Panasonic EVPV400H uses HJT (Heterojunction) cells, representing different technology generations.

Specifications Breakdown

Module Efficiency

The Maxeon Maxeon 6 425W achieves 22.2% module efficiency compared to Panasonic EVPV400H's 21.2%, meaning Maxeon Maxeon 6 425W converts 1.0 percentage points more sunlight into electricity per square meter. In practical terms, the Maxeon Maxeon 6 425W produces 220.0 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 Maxeon Maxeon 6 425W delivers 425W per panel versus 400W for the Panasonic EVPV400H, a 25W difference per module. To build an 8 kW residential system, you would need 19 Maxeon Maxeon 6 425W panels or 20 Panasonic EVPV400H panels. Choosing the higher-wattage option saves 1 panel, 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

The Panasonic EVPV400H has a temperature coefficient of -0.26%/°C versus -0.27%/°C for the Maxeon Maxeon 6 425W. 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 94.6%. 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 Maxeon Maxeon 6 425W is backed by a 40-year product warranty and 40-year performance guarantee, while the Panasonic EVPV400H offers 25-year product and 25-year performance coverage. The Maxeon Maxeon 6 425W provides 15 additional years of defect protection, covering manufacturing issues, material failures, and premature performance loss. Based on their published degradation rates (0.25% first year then 0.25%/year for Maxeon Maxeon 6 425W; 0.5% first year then 0.35%/year for Panasonic EVPV400H), after 25 years the Maxeon Maxeon 6 425W should retain approximately 93.8% of original output versus 91.1% for the Panasonic EVPV400H. This 2.7 percentage point gap in end-of-life output meaningfully impacts lifetime energy economics.

Physical Dimensions & Weight

The Maxeon Maxeon 6 425W measures 1872×1032×30mm and weighs 20.5 kg, while the Panasonic EVPV400H measures 1722×1134×30mm at 21 kg. 1.93 m² of panel area for the Maxeon Maxeon 6 425W 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 Maxeon Maxeon 6 425W Panasonic EVPV400H
Power 425W 400W
Efficiency 22.2% 21.2%
Power Density 20.4 W/sq ft 19.0 W/sq ft
Cell Type IBC (Interdigitated Back Contact) HJT (Heterojunction)
Bifacial Yes Yes
Weight 20.5 kg 21 kg
Temp Coefficient -0.27%/°C -0.26%/°C
Snow Load 5400 Pa 5400 Pa
Wind Load 3600 Pa 2400 Pa
Product Warranty 40 years 25 years
Performance Warranty 40 years 25 years
Degradation (Year 1) 0.25% 0.5%
Annual Degradation 0.25% 0.35%
Country Malaysia Japan

5-Dimension Head-to-Head Analysis

1. Efficiency & Power Density

Winner: Maxeon Maxeon 6 425W

The Maxeon Maxeon 6 425W achieves 22.2% efficiency versus 21.2% — a 1.0 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 0.8 kW more total system capacity, or 4 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 -0.27%/°C. On a 45°C summer day (20°C above STC), the winner retains 94.8% of rated power versus 94.6%. The difference is modest but accumulates over 25 years of summer production.

3. Durability & Warranty

Winner: Maxeon Maxeon 6 425W

Maxeon Maxeon 6 425W leads with a 40-year product warranty versus 25 years. Maxeon Maxeon 6 425W degrades more slowly at 0.25% per year versus 0.35%. After 25 years, expect 93.8% vs 91.1% of original output for Maxeon Maxeon 6 425W and Panasonic EVPV400H respectively.

4. Power Output

Winner: Maxeon Maxeon 6 425W

The Maxeon Maxeon 6 425W delivers 425W versus 400W per panel — 25W more. For an 8 kW system, you need 19 panels with the higher-wattage option versus 20 panels, saving 1 panels and the associated racking and labor costs.

5. Cell Technology

Winner: Tie

The Maxeon Maxeon 6 425W uses IBC (Interdigitated Back Contact): IBC (Interdigitated Back Contact) moves all electrical contacts to the rear of the cell, maximizing front-side light capture for the highest possible efficiency. 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. Both are equivalent-generation technologies.

Maxeon Maxeon 6 425W

The Maxeon 6 delivers 425W with 22.2% efficiency and the same industry-leading 40-year warranty as the Maxeon 7 series.

Pros

  • + 40-year complete warranty
  • + 22.2% IBC efficiency
  • + Excellent aesthetics
  • + Ultra-low degradation

Cons

  • - Very high cost per watt
  • - Limited installer network
  • - Fewer wattage options
View full Maxeon Maxeon 6 425W 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 Maxeon Maxeon 6 425W 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
  • Long-term warranty protection is a top priority and you plan to stay in your home for 40+ years
  • You want maximum output retention over the system's 25-30 year lifespan
  • Homeowners seeking a premium panel with the longest warranty available.

Choose Panasonic EVPV400H If...

  • You live in a hot climate (Arizona, Texas, Florida) where heat performance matters
  • You prefer newer cell technology with a longer performance improvement runway
  • No longer available for new installations.

Our Recommendation

Recommended Maxeon Maxeon 6 425W

The Maxeon Maxeon 6 425W is the decisive winner in this solar panel comparison, outperforming the Panasonic EVPV400H in 3 of 5 dimensions. Unless you have a specific requirement that the Panasonic EVPV400H uniquely addresses, the Maxeon Maxeon 6 425W is the stronger choice for virtually every installation scenario.

Frequently Asked Questions

Which is better, Maxeon Maxeon 6 425W or Panasonic EVPV400H?

The Maxeon Maxeon 6 425W wins this comparison by a decisive margin. It leads in efficiency (22.2% vs 21.2%) and matches or exceeds on warranty (40 vs 25 years). For most residential installations, the Maxeon Maxeon 6 425W is the stronger choice.

Which panel is more efficient, Maxeon Maxeon 6 425W or Panasonic EVPV400H?

The Maxeon Maxeon 6 425W at 22.2% module efficiency. Higher efficiency means more watts per square foot of roof space, which is critical for space-constrained installations. The difference of 1.0 percentage points translates to approximately 25W per panel under standard test conditions.

Which has a better warranty, Maxeon Maxeon 6 425W or Panasonic EVPV400H?

The Maxeon Maxeon 6 425W comes with a 40-year product warranty and 40-year performance guarantee. The Panasonic EVPV400H offers 25-year product and 25-year performance warranties. Maxeon Maxeon 6 425W provides 15 additional years of product coverage.

Which panel performs better in hot weather?

The Maxeon Maxeon 6 425W has a temperature coefficient of -0.27%/°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 Maxeon Maxeon 6 425W vs Panasonic EVPV400H panels do I need for an 8 kW system?

For an 8 kW system: you need 19 Maxeon Maxeon 6 425W panels (425W each) or 20 Panasonic EVPV400H panels (400W each). The Maxeon Maxeon 6 425W requires fewer panels, saving on racking hardware and installation labor.

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Last updated: February 2026