Hyundai HiE-S420VG Specifications & Review
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.
What Makes the Hyundai HiE-S420VG Different
The Hyundai HiE-S420VG brings Korean TOPCon N-type technology to the standard 108-cell residential form factor, matching the most common panel dimensions (1722 x 1134mm) used by the majority of residential racking systems. This is significant because many Korean and non-Chinese panels come in non-standard sizes that complicate racking and roof layout — the 420VG is specifically designed for the US residential market where the 108-cell format dominates. The 21.5% efficiency with -0.30%/°C temperature coefficient provides TOPCon N-type performance advantages over PERC in a direct drop-in replacement size. Hyundai's corporate warranty backing applies equally to this residential product, providing the same 25+25 year confidence.
Key Specifications
| Brand | Hyundai |
| Model | Hyundai HiE-S420VG 420W |
| Power Output | 420W |
| Efficiency | 21.5% |
| Power Density | 20.0 W/sq ft |
| Cell Type | TOPCon N-type |
| Cell Count | 108 cells |
| Dimensions | 1722 x 1134 x 30 mm |
| Weight | 21 kg |
| Open Circuit Voltage (Voc) | 44.8V |
| Max Power Voltage (Vmp) | 37.5V |
| Short Circuit Current (Isc) | 12.15A |
| Max Power Current (Imp) | 11.2A |
| Temp Coefficient (Pmax) | -0.3%/°C |
| Product Warranty | 25 years |
| Performance Warranty | 25 years |
| First Year Degradation | 1% |
| Annual Degradation | 0.4% |
| Country of Manufacture | South Korea |
| Certifications | IEC 61215, IEC 61730, UL 61730 |
| Snow Load | 5400 Pa (112.8 psf) — Heavy Snow Rated |
| Wind Load | 2400 Pa (50.1 psf) |
Pros & Cons
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
Best For
Residential homeowners wanting a standard-size Korean-manufactured TOPCon panel that fits any roof and racking system with strong corporate warranty backing.
Is the Hyundai HiE-S420VG Worth It?
The Hyundai HiE-S420VG delivers 420W of power at 21.5% module efficiency, which is above the current industry average of approximately 21%. This higher efficiency means you need fewer panels to reach your target system size, saving roof space and potentially reducing mounting hardware costs.
From a warranty perspective, the HiE-S420VG comes with a industry-leading 25-year product warranty and a 25-year performance guarantee. The industry standard for product warranties ranges from 12 to 25 years, so this panel sits at the top of that range, giving you long-term peace of mind. At the end of 25 years, the panel is guaranteed to still produce approximately 89.4% of its rated output, with first-year degradation of 1% and just 0.4% per year after that.
At around $0.44 per watt before installation, the HiE-S420VG sits in the mid-range price bracket, balancing cost and performance. For a typical 8 kW system using 20 panels, the panel cost alone would be approximately $3,520 before installation and incentives.
For hot climates, the temperature coefficient of -0.3%/°C is good. This falls within the typical range, so you can expect reasonable performance in most climates, though premium panels with coefficients closer to -0.25%/°C will edge ahead in extreme heat. Overall, the Hyundai HiE-S420VG represents a strong value proposition for most residential installations.
Real-World Performance
In the standard residential format, the HiE-S420VG performs as a direct upgrade from PERC panels of similar size. The TOPCon cells deliver approximately 2-3% more annual energy in hot climates due to the -0.30%/°C temperature coefficient, and the lower LID (first-year degradation approximately 0.8-1.0% vs 1.5-2.0% for PERC) means faster payback in year one. Monitoring data shows consistent output tracking within 1-2% of PVsyst models. The standard dimensions ensure identical wind loading and snow shedding characteristics as any other 108-cell panel, so structural engineering from existing installations can be directly applied. Cell-level quality is consistent with Hyundai's automotive-grade quality systems.
Who Should Buy the Hyundai HiE-S420VG?
System Design Tips
The 420VG is a direct drop-in for any system designed for standard 108-cell panels (1722 x 1134mm). String sizing, racking rail lengths, and roof layouts from existing PERC installations apply directly. The only adjustment is electrical — the Voc of 44.8V and Vmp of 37.5V may differ slightly from your PERC baseline, so recalculate string sizing accordingly (typically the same number of panels per string). For Enphase systems, the IQ8+ is appropriate for the 420W output. The 21.0 kg weight is standard for this format and within all residential racking specifications. The 30mm thickness is on the thin side, which may affect some rail clamp positions — verify clamp compatibility.
Price Estimate
The Hyundai HiE-S420VG typically costs $0.40-$0.50 per watt — a modest premium over Chinese 108-cell panels ($0.25-$0.35/W). For a 10 kW system (24 panels), module cost is approximately $4,000-$5,000. Complete installed system: $27,000-$36,000, or $18,900-$25,200 after 30% ITC. The premium over Chinese alternatives is approximately $1,500-$2,500 for a 10 kW system — modest enough that many buyers find Korean manufacturing and Hyundai warranty confidence worth the difference.
How the Hyundai HiE-S420VG Compares
| Model | Wattage | Efficiency | W/sq ft | Warranty | Snow Load | Cell Type |
|---|---|---|---|---|---|---|
| Hyundai HiE-S420VG (this panel) | 420W | 21.5% | 20.0 | 25 yrs | 5400 Pa | TOPCon N-type |
| Trina Solar Vertex S 420W | 420W | 21.3% | 19.5 | 15 yrs | 5400 Pa | PERC Mono |
| Canadian Solar CS6R 420W | 420W | 21% | 20.0 | 12 yrs | 5400 Pa | PERC Mono |
| REC TwinPeak 5 420W | 420W | 21.4% | 20.0 | 20 yrs | 5400 Pa | PERC Mono |
Compare This Panel
Installation & Compatibility
System Voltage & String Sizing
- Open Circuit Voltage (Voc)
- 44.8V
- Max Power Voltage (Vmp)
- 37.5V
- Short Circuit Current (Isc)
- 12.15A
- Max Power Current (Imp)
- 11.2A
- Max Panels per String (600V)
- 13 panels
Based on NEC 600V residential limit. Actual string sizing should account for cold-temperature Voc rise. Consult your installer or use a string sizing tool for your specific location.
Mounting Requirements
- Dimensions
- 1722 x 1134 x 30 mm
- Weight
- 21 kg (46.3 lbs)
- Area per Panel
- 21.0 sq ft
- Weight per sq ft
- 2.2 lbs/sq ft
Recommended Inverter Types
- - Microinverters: Ideal for shaded roofs or complex layouts. Match to panels rated 420W+.
- - String Inverters: Cost-effective for unshaded arrays. Ensure MPPT range covers 37.5V.
- - Hybrid Inverters: Best if adding battery storage. Check DC input specs match panel Voc of 44.8V.
Frequently Asked Questions
Why choose the Hyundai 420VG over a Chinese 420-440W TOPCon panel?
Three reasons: (1) Korean manufacturing provides supply chain diversification and avoids UFLPA scrutiny, (2) Hyundai's conglomerate backing provides superior warranty confidence vs solar-only manufacturers, (3) consistent quality from automotive-derived manufacturing systems. The trade-off is a 15-25% per-watt premium. If cost is the only factor, Chinese panels win; if warranty confidence and supply chain matter, Hyundai is compelling.
Is 420W competitive for a 108-cell panel in 2026?
420W is competitive but not class-leading for 108-cell panels. Chinese manufacturers like JinkoSolar offer 440-450W in the same format. The 420W output means approximately 5% more panels for the same system size (24 panels for 10 kW vs 23 with 440W). For most residential roofs, this difference is negligible. The Hyundai's value proposition is Korean quality and warranty, not peak wattage.
Can I mix Hyundai panels with existing panels from a different brand?
Mixing panel brands is generally not recommended on the same string inverter string due to electrical mismatch losses. With microinverters (Enphase) or DC optimizers (SolarEdge), mixing brands is acceptable because each panel operates independently. If expanding an existing array, ensure the new Hyundai panels are on separate microinverters or a separate string from existing panels.
What is the efficiency of the Hyundai HiE-S420VG?
The Hyundai HiE-S420VG achieves 21.5% module efficiency using TOPCon N-type cell technology. This is around the industry average for residential solar panels in 2026.
What warranty does the Hyundai HiE-S420VG include?
It comes with a 25-year product warranty and a 25-year performance warranty guaranteeing output at approximately 89.4% of rated power at the end of the warranty period.
How does the Hyundai HiE-S420VG perform in hot weather?
With a temperature coefficient of -0.3%/°C, the HiE-S420VG experiences moderate power reduction in high temperatures. Every degree above 25°C reduces output by 0.3%.
What size system can I build with the Hyundai HiE-S420VG?
At 420W per panel, you would need approximately 20 panels for an 8 kW system or 24 panels for a 10 kW system. Each panel measures 1722 x 1134 mm (21.0 sq ft).
What inverter is best with the Hyundai HiE-S420VG?
The Hyundai HiE-S420VG works well with both string inverters and microinverters. For string inverters, choose one with a maximum input voltage above 44.8V and an MPPT voltage range that covers 37.5V. Microinverters rated for 420W+ panels are also an excellent choice, offering panel-level monitoring and shade tolerance. Popular options include Enphase IQ8 series microinverters and SolarEdge string inverters with power optimizers.
How long will the Hyundai HiE-S420VG last?
The Hyundai HiE-S420VG is built to last well beyond its 25-year performance warranty. With first-year degradation of 1% and annual degradation of 0.4% thereafter, the panel will still produce approximately 89.4% of its rated power after 25 years. Most modern solar panels continue generating useful power for 30-40 years, though output gradually decreases over time.
Is the Hyundai HiE-S420VG good for Arizona and other sunny states?
The Hyundai HiE-S420VG can work in hot states like Arizona, Nevada, and Texas, though its temperature coefficient of -0.3%/°C means it will lose some output on the hottest days. Consider panels with a lower (closer to 0) temperature coefficient if you live in an area with extreme heat. Higher sun exposure in these states means more total energy production throughout the year, often offsetting any heat-related losses.
Is the Hyundai HiE-S420VG worth the money?
The Hyundai HiE-S420VG delivers 21.5% efficiency at approximately $0.44/W, which is above the industry average of ~21%. Combined with a industry-leading 25-year product warranty and 25-year performance guarantee, it offers strong value for homeowners seeking reliable solar generation.
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Last updated: February 2026