Solaria PowerXT 400R Pure Black vs Hyundai HiE-S420VG
The Hyundai HiE-S420VG wins this comparison by a clear margin. It leads in efficiency (21.5% vs 20.5%) and matches or exceeds on warranty (25 vs 25 years). For most residential installations, the Hyundai HiE-S420VG is the stronger choice.
Key Differences
- • Solaria PowerXT 400R Pure Black is rated at 400W while Hyundai HiE-S420VG is rated at 420W, a 20W difference.
- • Hyundai HiE-S420VG achieves 21.5% efficiency vs 20.5% for the other, a 1.0 percentage point gap.
- • Both carry matching 25-year product warranties.
- • Hyundai HiE-S420VG has a superior temperature coefficient of -0.3%/°C vs -0.34%/°C, retaining more power in hot climates.
- • Solaria PowerXT 400R Pure Black uses Shingled Mono PERC cells while Hyundai HiE-S420VG uses TOPCon N-type cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The Hyundai HiE-S420VG achieves 21.5% module efficiency compared to Solaria PowerXT 400R Pure Black's 20.5%, meaning Hyundai HiE-S420VG converts 1.0 percentage points more sunlight into electricity per square meter. In practical terms, the Solaria PowerXT 400R Pure Black produces 205.3 watts per square meter of panel area while the Hyundai HiE-S420VG produces 215.1 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 Hyundai HiE-S420VG delivers 420W per panel versus 400W for the Solaria PowerXT 400R Pure Black, a 20W difference per module. To build an 8 kW residential system, you would need 20 Solaria PowerXT 400R Pure Black panels or 20 Hyundai HiE-S420VG 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 Hyundai HiE-S420VG has a temperature coefficient of -0.3%/°C versus -0.34%/°C for the Solaria PowerXT 400R Pure Black. On a hot summer day when cell temperature reaches 65°C (40°C above the 25°C STC baseline), the Hyundai HiE-S420VG retains 94.0% of its rated power while the other retains 93.2%. 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 Solaria PowerXT 400R Pure Black is backed by a 25-year product warranty and 25-year performance guarantee, while the Hyundai HiE-S420VG offers 25-year product and 25-year performance coverage. Both offer identical product warranty duration. Based on their published degradation rates (1.5% first year then 0.4%/year for Solaria PowerXT 400R Pure Black; 1% first year then 0.4%/year for Hyundai HiE-S420VG), after 25 years the Solaria PowerXT 400R Pure Black should retain approximately 88.9% of original output versus 89.4% for the Hyundai HiE-S420VG. The end-of-life output levels are closely matched.
Physical Dimensions & Weight
The Solaria PowerXT 400R Pure Black measures 1812×1075×40mm and weighs 21.5 kg, while the Hyundai HiE-S420VG measures 1722×1134×30mm at 21 kg. 1.95 m² of panel area for the Solaria PowerXT 400R Pure Black versus 1.95 m² for the Hyundai HiE-S420VG. 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 | Solaria PowerXT 400R Pure Black | Hyundai HiE-S420VG |
|---|---|---|
| Power | 400W | 420W |
| Efficiency | 20.5% | 21.5% |
| Power Density | 19.1 W/sq ft | 20.0 W/sq ft |
| Cell Type | Shingled Mono PERC | TOPCon N-type |
| Bifacial | No | No |
| Weight | 21.5 kg | 21 kg |
| Temp Coefficient | -0.34%/°C | -0.3%/°C |
| Snow Load | 5400 Pa | 5400 Pa |
| Wind Load | 2400 Pa | 2400 Pa |
| Product Warranty | 25 years | 25 years |
| Performance Warranty | 25 years | 25 years |
| Degradation (Year 1) | 1.5% | 1% |
| Annual Degradation | 0.4% | 0.4% |
| Country | USA | South Korea |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: Hyundai HiE-S420VGThe Hyundai HiE-S420VG achieves 21.5% efficiency versus 20.5% — a 1.0 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: Hyundai HiE-S420VGThe Hyundai HiE-S420VG has a better temperature coefficient of -0.3%/°C versus -0.34%/°C. On a 45°C summer day (20°C above STC), the winner retains 94.0% of rated power versus 93.2%. The difference is modest but accumulates over 25 years of summer production.
3. Durability & Warranty
Winner: TieBoth panels offer identical 25-year product warranties and 0.4% annual degradation. Neither has a durability advantage.
4. Power Output
Winner: Hyundai HiE-S420VGThe Hyundai HiE-S420VG 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: Hyundai HiE-S420VGThe Solaria PowerXT 400R Pure Black uses Shingled Mono PERC: PERC (Passivated Emitter Rear Cell) is the current mainstream technology, offering good efficiency at the lowest manufacturing cost. The Hyundai HiE-S420VG 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. TOPCon N-type represents a newer generation technology with a longer performance runway as manufacturing matures.
Solaria PowerXT 400R Pure Black
The Solaria PowerXT 400R Pure Black is the compact residential variant of Solaria's shingled-cell panel line, delivering 400W in a smaller form factor optimized for constrained rooftops. The shingled cell architecture produces a completely uniform black surface — no visible busbars, cell gaps, or gridlines — making it one of the most aesthetically appealing panels on the market. Manufactured in Fremont, California, it qualifies for domestic content bonus ITC credits. The 400W output in a compact footprint makes it suitable for smaller residential roofs where every square foot counts.
Pros
- + Industry-leading all-black aesthetics — completely uniform surface
- + Compact size fits constrained residential rooftops
- + US-manufactured — domestic content ITC bonus eligible
- + Shingled cells improve shade tolerance and eliminate hot spots
- + 25-year dual warranty (product + performance)
- + No busbar visibility for premium curb appeal
Cons
- - 400W output lower than larger-format competitors
- - Higher per-watt cost for the aesthetic and US-made premium
- - Smaller installer network than mainstream brands
- - 20.5% efficiency is good but not class-leading
Hyundai HiE-S420VG
The Hyundai HiE-S420VG is a 420W residential-format TOPCon N-type panel in the popular 108-cell configuration (1722 x 1134mm), matching the most common residential panel size for easy racking and roof fit. Korean manufacturing provides supply chain diversification, and the TOPCon N-type cells deliver better temperature performance (-0.30%/°C) and lower degradation than PERC alternatives. The standard residential form factor ensures compatibility with all major racking systems.
Pros
- + Standard 108-cell residential size — fits any racking system
- + Korean-made TOPCon N-type with 21.5% efficiency
- + -0.30%/°C temperature coefficient for hot climate performance
- + 25+25 year warranty backed by Hyundai corporate
- + Non-Chinese manufacturing for tariff and UFLPA considerations
- + 420W competitive output in standard residential format
Cons
- - 420W is competitive but not class-leading for 108-cell panels
- - Slightly higher per-watt cost than Chinese equivalents
- - Smaller US installer network and distribution
- - Less brand recognition in solar market despite Hyundai name
Choose Solaria PowerXT 400R Pure Black If...
- ✓ Homeowners with visible roof installations who demand the best-looking all-black panel with American manufacturing and domestic content tax benefits.
Choose Hyundai HiE-S420VG 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 live in a hot climate (Arizona, Texas, Florida) where heat performance matters
- ✓ You prefer newer cell technology with a longer performance improvement runway
- ✓ Residential homeowners wanting a standard-size Korean-manufactured TOPCon panel that fits any roof and racking system with strong corporate warranty backing.
Our Recommendation
We recommend the Hyundai HiE-S420VG for most buyers in this comparison. It wins 4 of 5 key dimensions and offers a clear advantage in the metrics that matter most for a solar panel purchase. The Solaria PowerXT 400R Pure Black remains a good product, but the Hyundai HiE-S420VG delivers better overall value for the majority of installations.
Frequently Asked Questions
Which is better, Solaria PowerXT 400R Pure Black or Hyundai HiE-S420VG?
The Hyundai HiE-S420VG wins this comparison by a clear margin. It leads in efficiency (21.5% vs 20.5%) and matches or exceeds on warranty (25 vs 25 years). For most residential installations, the Hyundai HiE-S420VG is the stronger choice.
Which panel is more efficient, Solaria PowerXT 400R Pure Black or Hyundai HiE-S420VG?
The Hyundai HiE-S420VG at 21.5% 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 20W per panel under standard test conditions.
Which has a better warranty, Solaria PowerXT 400R Pure Black or Hyundai HiE-S420VG?
The Solaria PowerXT 400R Pure Black comes with a 25-year product warranty and 25-year performance guarantee. The Hyundai HiE-S420VG offers 25-year product and 25-year performance warranties. Both offer identical warranty terms.
Which panel performs better in hot weather?
The Solaria PowerXT 400R Pure Black has a temperature coefficient of -0.34%/°C and the Hyundai HiE-S420VG is -0.3%/°C. Hyundai HiE-S420VG retains more power in heat — important in states like Arizona, Texas, and Florida. A lower (less negative) temperature coefficient is better.
How many Solaria PowerXT 400R Pure Black vs Hyundai HiE-S420VG panels do I need for an 8 kW system?
For an 8 kW system: you need 20 Solaria PowerXT 400R Pure Black panels (400W each) or 20 Hyundai HiE-S420VG panels (420W each). The Hyundai HiE-S420VG requires fewer panels, saving on racking hardware and installation labor.
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Last updated: February 2026