CertainTeed Solstice Solar Panel 365W vs Hyundai HiE-S420VG
The Hyundai HiE-S420VG wins this comparison by a decisive margin. It leads in efficiency (21.5% vs 19.9%) and matches or exceeds on warranty (25 vs 10 years). For most residential installations, the Hyundai HiE-S420VG is the stronger choice.
Key Differences
- • CertainTeed Solstice Solar Panel 365W is rated at 365W while Hyundai HiE-S420VG is rated at 420W, a 55W difference.
- • Hyundai HiE-S420VG achieves 21.5% efficiency vs 19.9% for the other, a 1.6 percentage point gap.
- • Hyundai HiE-S420VG comes with a 25-year product warranty vs 10 years for the other.
- • Hyundai HiE-S420VG has a superior temperature coefficient of -0.3%/°C vs -0.36%/°C, retaining more power in hot climates.
- • CertainTeed Solstice Solar Panel 365W uses Monocrystalline 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 CertainTeed Solstice Solar Panel 365W's 19.9%, meaning Hyundai HiE-S420VG converts 1.6 percentage points more sunlight into electricity per square meter. In practical terms, the CertainTeed Solstice Solar Panel 365W produces 199.2 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 365W for the CertainTeed Solstice Solar Panel 365W, a 55W difference per module. To build an 8 kW residential system, you would need 22 CertainTeed Solstice Solar Panel 365W panels or 20 Hyundai HiE-S420VG panels. Choosing the higher-wattage option saves 2 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 Hyundai HiE-S420VG has a temperature coefficient of -0.3%/°C versus -0.36%/°C for the CertainTeed Solstice Solar Panel 365W. 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 92.8%. This difference is particularly significant in hot climates such as the American Southwest, the Middle East, and Southeast Asia, where panels routinely operate 30-40°C above STC for several hours each day. Over the system lifetime, the cumulative energy advantage from a better temperature coefficient can amount to 2-4% of total production.
Warranty Coverage
The CertainTeed Solstice Solar Panel 365W is backed by a 10-year product warranty and 25-year performance guarantee, while the Hyundai HiE-S420VG offers 25-year product and 25-year performance coverage. The Hyundai HiE-S420VG provides 15 additional years of defect protection, covering manufacturing issues, material failures, and premature performance loss. Based on their published degradation rates (2% first year then 0.55%/year for CertainTeed Solstice Solar Panel 365W; 1% first year then 0.4%/year for Hyundai HiE-S420VG), after 25 years the CertainTeed Solstice Solar Panel 365W should retain approximately 84.8% of original output versus 89.4% for the Hyundai HiE-S420VG. This 4.6 percentage point gap in end-of-life output meaningfully impacts lifetime energy economics.
Physical Dimensions & Weight
The CertainTeed Solstice Solar Panel 365W measures 1755×1044×40mm and weighs 21.6 kg, while the Hyundai HiE-S420VG measures 1722×1134×30mm at 21 kg. 1.83 m² of panel area for the CertainTeed Solstice Solar Panel 365W 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. The more compact CertainTeed Solstice Solar Panel 365W may be easier to fit on irregularly shaped or space-limited rooftops.
Specification Comparison
| Specification | CertainTeed Solstice Solar Panel 365W | Hyundai HiE-S420VG |
|---|---|---|
| Power | 365W | 420W |
| Efficiency | 19.9% | 21.5% |
| Power Density | 18.5 W/sq ft | 20.0 W/sq ft |
| Cell Type | Monocrystalline PERC | TOPCon N-type |
| Bifacial | No | No |
| Weight | 21.6 kg | 21 kg |
| Temp Coefficient | -0.36%/°C | -0.3%/°C |
| Snow Load | 5400 Pa | 5400 Pa |
| Wind Load | 2400 Pa | 2400 Pa |
| Product Warranty | 10 years | 25 years |
| Performance Warranty | 25 years | 25 years |
| Degradation (Year 1) | 2% | 1% |
| Annual Degradation | 0.55% | 0.4% |
| Country | United States | South Korea |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: Hyundai HiE-S420VGThe Hyundai HiE-S420VG achieves 21.5% efficiency versus 19.9% — a 1.6 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 1.6 kW more total system capacity, or 8 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 -0.36%/°C. On a 45°C summer day (20°C above STC), the winner retains 94.0% of rated power versus 92.8%. This is a meaningful difference in hot states like Arizona, Texas, and Florida.
3. Durability & Warranty
Winner: Hyundai HiE-S420VGHyundai HiE-S420VG leads with a 25-year product warranty versus 10 years. Hyundai HiE-S420VG degrades more slowly at 0.4% per year versus 0.55%. After 25 years, expect 84.8% vs 89.4% of original output for CertainTeed Solstice Solar Panel 365W and Hyundai HiE-S420VG respectively.
4. Power Output
Winner: Hyundai HiE-S420VGThe Hyundai HiE-S420VG delivers 420W versus 365W per panel — 55W more. For an 8 kW system, you need 20 panels with the higher-wattage option versus 22 panels, saving 2 panels and the associated racking and labor costs.
5. Cell Technology
Winner: Hyundai HiE-S420VGThe CertainTeed Solstice Solar Panel 365W uses Monocrystalline 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.
CertainTeed Solstice Solar Panel 365W
The CertainTeed Solstice Solar Panel 365W is a conventional residential solar panel from CertainTeed (Saint-Gobain), using monocrystalline PERC half-cut cells. Designed to pair with CertainTeed roofing products for a coordinated roof-and-solar installation through certified roofing contractors.
Pros
- + Made in the USA by Saint-Gobain subsidiary
- + 10-year product warranty — strong for US-manufactured panel
- + Designed for seamless pairing with CertainTeed roofing
- + Half-cut PERC cells for partial shade resilience
- + Available through established roofing contractor network
Cons
- - 19.9% efficiency below current N-Type leaders
- - 365W output lower than modern 400W+ panels
- - Heavier at 21.6 kg than comparable wattage panels
- - Higher cost per watt than budget alternatives
- - Limited distribution outside CertainTeed roofing dealers
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 CertainTeed Solstice Solar Panel 365W If...
- ✓ Homeowners doing a combined roof replacement and solar installation through CertainTeed-certified contractors.
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
- ✓ Long-term warranty protection is a top priority and you plan to stay in your home for 25+ years
- ✓ 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
Our Recommendation
The Hyundai HiE-S420VG is the decisive winner in this solar panel comparison, outperforming the CertainTeed Solstice Solar Panel 365W in 5 of 5 dimensions. Unless you have a specific requirement that the CertainTeed Solstice Solar Panel 365W uniquely addresses, the Hyundai HiE-S420VG is the stronger choice for virtually every installation scenario.
Frequently Asked Questions
Which is better, CertainTeed Solstice Solar Panel 365W or Hyundai HiE-S420VG?
The Hyundai HiE-S420VG wins this comparison by a decisive margin. It leads in efficiency (21.5% vs 19.9%) and matches or exceeds on warranty (25 vs 10 years). For most residential installations, the Hyundai HiE-S420VG is the stronger choice.
Which panel is more efficient, CertainTeed Solstice Solar Panel 365W 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 1.6 percentage points translates to approximately 55W per panel under standard test conditions.
Which has a better warranty, CertainTeed Solstice Solar Panel 365W or Hyundai HiE-S420VG?
The CertainTeed Solstice Solar Panel 365W comes with a 10-year product warranty and 25-year performance guarantee. The Hyundai HiE-S420VG offers 25-year product and 25-year performance warranties. Hyundai HiE-S420VG provides 15 additional years of product coverage.
Which panel performs better in hot weather?
The CertainTeed Solstice Solar Panel 365W has a temperature coefficient of -0.36%/°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 CertainTeed Solstice Solar Panel 365W vs Hyundai HiE-S420VG panels do I need for an 8 kW system?
For an 8 kW system: you need 22 CertainTeed Solstice Solar Panel 365W panels (365W each) or 20 Hyundai HiE-S420VG panels (420W each). The Hyundai HiE-S420VG requires fewer panels, saving on racking hardware and installation labor.
Related Resources
Last updated: February 2026