Silfab SIL-500-NX 500W vs Hyundai HiE-S420VG

Our Verdict Winner: Silfab SIL-500-NX 500W

The Silfab SIL-500-NX 500W wins this comparison by a clear margin. It leads in efficiency (21.8% vs 21.5%) and matches or exceeds on warranty (25 vs 25 years). For most residential installations, the Silfab SIL-500-NX 500W is the stronger choice.

Power / Capacity

500W

420W

Efficiency

21.8%

21.5%

Warranty

25 yrs

Key Differences

• Silfab SIL-500-NX 500W is rated at 500W while Hyundai HiE-S420VG is rated at 420W, a 80W difference.
• Silfab SIL-500-NX 500W achieves 21.8% efficiency vs 21.5% for the other, a 0.3 percentage point gap.
• Both carry matching 25-year product warranties.
• Silfab SIL-500-NX 500W has a superior temperature coefficient of -0.29%/°C vs -0.3%/°C, retaining more power in hot climates.

Specifications Breakdown

Module Efficiency

The Silfab SIL-500-NX 500W achieves 21.8% module efficiency compared to Hyundai HiE-S420VG's 21.5%, meaning Silfab SIL-500-NX 500W converts 0.3 percentage points more sunlight into electricity per square meter. In practical terms, the Silfab SIL-500-NX 500W produces 210.6 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 Silfab SIL-500-NX 500W delivers 500W per panel versus 420W for the Hyundai HiE-S420VG, a 80W difference per module. To build an 8 kW residential system, you would need 16 Silfab SIL-500-NX 500W panels or 20 Hyundai HiE-S420VG panels. Choosing the higher-wattage option saves 4 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

The Silfab SIL-500-NX 500W has a temperature coefficient of -0.29%/°C versus -0.3%/°C for the Hyundai HiE-S420VG. On a hot summer day when cell temperature reaches 65°C (40°C above the 25°C STC baseline), the Silfab SIL-500-NX 500W retains 94.2% of its rated power while the other retains 94.0%. 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 Silfab SIL-500-NX 500W is backed by a 25-year product warranty and 30-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% first year then 0.4%/year for Silfab SIL-500-NX 500W; 1% first year then 0.4%/year for Hyundai HiE-S420VG), after 25 years the Silfab SIL-500-NX 500W should retain approximately 89.4% of original output versus 89.4% for the Hyundai HiE-S420VG. The end-of-life output levels are closely matched.

Physical Dimensions & Weight

The Silfab SIL-500-NX 500W measures 2094×1134×30mm and weighs 25.5 kg, while the Hyundai HiE-S420VG measures 1722×1134×30mm at 21 kg. 2.37 m² of panel area for the Silfab SIL-500-NX 500W versus 1.95 m² for the Hyundai HiE-S420VG. The Hyundai HiE-S420VG is 4.5 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 90 kg. The more compact Hyundai HiE-S420VG may be easier to fit on irregularly shaped or space-limited rooftops.

Specification Comparison

Specification	Silfab SIL-500-NX 500W	Hyundai HiE-S420VG
Power	500W	420W
Efficiency	21.8%	21.5%
Power Density	19.6 W/sq ft	20.0 W/sq ft
Cell Type	TOPCon N-type	TOPCon N-type
Bifacial	No	No
Weight	25.5 kg	21 kg
Temp Coefficient	-0.29%/°C	-0.3%/°C
Snow Load	5400 Pa	5400 Pa
Wind Load	2400 Pa	2400 Pa
Product Warranty	25 years	25 years
Performance Warranty	30 years	25 years
Degradation (Year 1)	1%	1%
Annual Degradation	0.4%	0.4%
Country	United States	South Korea

5-Dimension Head-to-Head Analysis

1. Efficiency & Power Density

Winner: Silfab SIL-500-NX 500W

The Silfab SIL-500-NX 500W achieves 21.8% efficiency versus 21.5% — a 0.3 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 2.4 kW more total system capacity, or 11 kWh more annual production in an average US location.

2. Hot Climate Performance

Winner: Silfab SIL-500-NX 500W

The Silfab SIL-500-NX 500W has a better temperature coefficient of -0.29%/°C versus -0.3%/°C. On a 45°C summer day (20°C above STC), the winner retains 94.2% of rated power versus 94.0%. The difference is modest but accumulates over 25 years of summer production.

3. Durability & Warranty

Winner: Tie

Both panels offer identical 25-year product warranties and 0.4% annual degradation. Neither has a durability advantage.

4. Power Output

Winner: Silfab SIL-500-NX 500W

The Silfab SIL-500-NX 500W delivers 500W versus 420W per panel — 80W more. For an 8 kW system, you need 16 panels with the higher-wattage option versus 20 panels, saving 4 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.

Silfab SIL-500-NX 500W

Silfab SIL-500-NX is a US-manufactured N-type TOPCon panel delivering 500W with domestic production benefits and a 25-year warranty.

Pros

+ Made in USA
+ 25-year product warranty
+ N-type TOPCon technology
+ Strong domestic support

Cons

- Higher cost than imports
- Moderate efficiency
- Limited brand awareness

View full Silfab SIL-500-NX 500W specs →

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

View full Hyundai HiE-S420VG specs →

Choose Silfab SIL-500-NX 500W 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
✓ Homeowners prioritizing US-made solar panels with strong domestic warranty.

Choose Hyundai HiE-S420VG If...

✓ 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

Recommended Silfab SIL-500-NX 500W

We recommend the Silfab SIL-500-NX 500W for most buyers in this comparison. It wins 3 of 5 key dimensions and offers a clear advantage in the metrics that matter most for a solar panel purchase. The Hyundai HiE-S420VG remains a good product, but the Silfab SIL-500-NX 500W delivers better overall value for the majority of installations.

View Silfab SIL-500-NX 500W specs → View Hyundai HiE-S420VG specs →

Frequently Asked Questions

Which is better, Silfab SIL-500-NX 500W or Hyundai HiE-S420VG?

Which panel is more efficient, Silfab SIL-500-NX 500W or Hyundai HiE-S420VG?

The Silfab SIL-500-NX 500W at 21.8% module efficiency. Higher efficiency means more watts per square foot of roof space, which is critical for space-constrained installations. The difference of 0.3 percentage points translates to approximately 80W per panel under standard test conditions.

Which has a better warranty, Silfab SIL-500-NX 500W or Hyundai HiE-S420VG?

The Silfab SIL-500-NX 500W comes with a 25-year product warranty and 30-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 Silfab SIL-500-NX 500W has a temperature coefficient of -0.29%/°C and the Hyundai HiE-S420VG is -0.3%/°C. Silfab SIL-500-NX 500W retains more power in heat — important in states like Arizona, Texas, and Florida. A lower (less negative) temperature coefficient is better.

How many Silfab SIL-500-NX 500W vs Hyundai HiE-S420VG panels do I need for an 8 kW system?

For an 8 kW system: you need 16 Silfab SIL-500-NX 500W panels (500W each) or 20 Hyundai HiE-S420VG panels (420W each). The Silfab SIL-500-NX 500W requires fewer panels, saving on racking hardware and installation labor.

Related Resources

View full Silfab SIL-500-NX 500W specifications → View full Hyundai HiE-S420VG specifications → All Silfab products → All Hyundai products →

Last updated: February 2026