Hyundai HiE-S420VG vs Heliene 144HJT 440W
The Heliene 144HJT 440W wins this comparison by a clear margin. It delivers more power (440W vs 420W). For most residential installations, the Heliene 144HJT 440W is the stronger choice.
Key Differences
- • Hyundai HiE-S420VG is rated at 420W while Heliene 144HJT 440W is rated at 440W, a 20W difference.
- • Hyundai HiE-S420VG achieves 21.5% efficiency vs 21% for the other, a 0.5 percentage point gap.
- • Both carry matching 25-year product warranties.
- • Heliene 144HJT 440W has a superior temperature coefficient of -0.26%/°C vs -0.3%/°C, retaining more power in hot climates.
- • Hyundai HiE-S420VG uses TOPCon N-type cells while Heliene 144HJT 440W uses HJT (Heterojunction) N-type cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The Hyundai HiE-S420VG achieves 21.5% module efficiency compared to Heliene 144HJT 440W's 21%, meaning Hyundai HiE-S420VG converts 0.5 percentage points more sunlight into electricity per square meter. In practical terms, the Hyundai HiE-S420VG produces 215.1 watts per square meter of panel area while the Heliene 144HJT 440W produces 202.2 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 Heliene 144HJT 440W delivers 440W per panel versus 420W for the Hyundai HiE-S420VG, a 20W difference per module. To build an 8 kW residential system, you would need 20 Hyundai HiE-S420VG panels or 19 Heliene 144HJT 440W 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 Heliene 144HJT 440W has a temperature coefficient of -0.26%/°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 Heliene 144HJT 440W retains 94.8% 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 Hyundai HiE-S420VG is backed by a 25-year product warranty and 25-year performance guarantee, while the Heliene 144HJT 440W offers 25-year product and 30-year performance coverage. Both offer identical product warranty duration. Based on their published degradation rates (1% first year then 0.4%/year for Hyundai HiE-S420VG; 1% first year then 0.35%/year for Heliene 144HJT 440W), after 25 years the Hyundai HiE-S420VG should retain approximately 89.4% of original output versus 90.6% for the Heliene 144HJT 440W. This 1.2 percentage point gap in end-of-life output meaningfully impacts lifetime energy economics.
Physical Dimensions & Weight
The Hyundai HiE-S420VG measures 1722×1134×30mm and weighs 21 kg, while the Heliene 144HJT 440W measures 2094×1039×35mm at 24 kg. 1.95 m² of panel area for the Hyundai HiE-S420VG versus 2.18 m² for the Heliene 144HJT 440W. The Hyundai HiE-S420VG is 3.0 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 60 kg. The more compact Hyundai HiE-S420VG may be easier to fit on irregularly shaped or space-limited rooftops.
Specification Comparison
| Specification | Hyundai HiE-S420VG | Heliene 144HJT 440W |
|---|---|---|
| Power | 420W | 440W |
| Efficiency | 21.5% | 21% |
| Power Density | 20.0 W/sq ft | 18.8 W/sq ft |
| Cell Type | TOPCon N-type | HJT (Heterojunction) N-type |
| Bifacial | No | Yes |
| Weight | 21 kg | 24 kg |
| Temp Coefficient | -0.3%/°C | -0.26%/°C |
| Snow Load | 5400 Pa | 5400 Pa |
| Wind Load | 2400 Pa | 2400 Pa |
| Product Warranty | 25 years | 25 years |
| Performance Warranty | 25 years | 30 years |
| Degradation (Year 1) | 1% | 1% |
| Annual Degradation | 0.4% | 0.35% |
| Country | South Korea | Canada |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: Hyundai HiE-S420VGThe Hyundai HiE-S420VG achieves 21.5% efficiency versus 21% — a 0.5 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: Heliene 144HJT 440WThe Heliene 144HJT 440W has a better temperature coefficient of -0.26%/°C versus -0.3%/°C. On a 45°C summer day (20°C above STC), the winner retains 94.8% of rated power versus 94.0%. The difference is modest but accumulates over 25 years of summer production.
3. Durability & Warranty
Winner: Heliene 144HJT 440WHeliene 144HJT 440W degrades more slowly at 0.35% per year versus 0.4%. After 25 years, expect 89.4% vs 90.6% of original output for Hyundai HiE-S420VG and Heliene 144HJT 440W respectively.
4. Power Output
Winner: Heliene 144HJT 440WThe Heliene 144HJT 440W delivers 440W versus 420W per panel — 20W 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: Heliene 144HJT 440WThe 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. The Heliene 144HJT 440W uses HJT (Heterojunction) N-type: HJT (Heterojunction) combines crystalline silicon with amorphous silicon layers, delivering the best temperature coefficient and bifacial gains, but at higher manufacturing cost. HJT (Heterojunction) N-type represents a newer generation technology with a longer performance runway as manufacturing matures.
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
Heliene 144HJT 440W
The Heliene 144HJT 440W is a heterojunction (HJT) N-type panel manufactured in Ontario, Canada, combining the best temperature coefficient in the industry (-0.26%/°C) with North American manufacturing. Heliene operates factories in both Canada and Minnesota, making it one of the few solar panel manufacturers with production facilities in North America. The HJT cell technology delivers exceptional low-light performance and bifacial capability, while the 30-year performance warranty (with only 0.35% annual degradation) guarantees long-term energy production. Qualifies for domestic content bonus ITC credits under IRA provisions.
Pros
- + Manufactured in Canada — North American supply chain
- + -0.26%/°C temperature coefficient — HJT advantage in hot climates
- + 30-year performance warranty with 0.35% annual degradation
- + Qualifies for IRA domestic content bonus ITC credits
- + HJT cells deliver excellent early morning and late afternoon performance
- + 25-year product warranty with accessible North American support
Cons
- - 440W is modest compared to 500W+ panels in similar size
- - Higher per-watt cost than Chinese-manufactured alternatives
- - Smaller brand recognition than Tier-1 Chinese manufacturers
- - HJT technology is more expensive to manufacture than TOPCon
Choose Hyundai HiE-S420VG If...
- ✓ Your roof space is limited and you need maximum power per panel
- ✓ 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.
Choose Heliene 144HJT 440W If...
- ✓ 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 want maximum output retention over the system's 25-30 year lifespan
- ✓ You prefer newer cell technology with a longer performance improvement runway
- ✓ North American homeowners who want locally manufactured HJT panels with domestic content ITC bonus eligibility and the best hot-climate temperature performance.
Our Recommendation
We recommend the Heliene 144HJT 440W 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 Hyundai HiE-S420VG remains a good product, but the Heliene 144HJT 440W delivers better overall value for the majority of installations.
Frequently Asked Questions
Which is better, Hyundai HiE-S420VG or Heliene 144HJT 440W?
The Heliene 144HJT 440W wins this comparison by a clear margin. It delivers more power (440W vs 420W). For most residential installations, the Heliene 144HJT 440W is the stronger choice.
Which panel is more efficient, Hyundai HiE-S420VG or Heliene 144HJT 440W?
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 0.5 percentage points translates to approximately 20W per panel under standard test conditions.
Which has a better warranty, Hyundai HiE-S420VG or Heliene 144HJT 440W?
The Hyundai HiE-S420VG comes with a 25-year product warranty and 25-year performance guarantee. The Heliene 144HJT 440W offers 25-year product and 30-year performance warranties. Both offer identical warranty terms.
Which panel performs better in hot weather?
The Hyundai HiE-S420VG has a temperature coefficient of -0.3%/°C and the Heliene 144HJT 440W is -0.26%/°C. Heliene 144HJT 440W retains more power in heat — important in states like Arizona, Texas, and Florida. A lower (less negative) temperature coefficient is better.
How many Hyundai HiE-S420VG vs Heliene 144HJT 440W panels do I need for an 8 kW system?
For an 8 kW system: you need 20 Hyundai HiE-S420VG panels (420W each) or 19 Heliene 144HJT 440W panels (440W each). The Heliene 144HJT 440W requires fewer panels, saving on racking hardware and installation labor.
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Last updated: February 2026