Silfab SIL-370-BK 370W vs Solaria PowerXT 430R
The Solaria PowerXT 430R wins this comparison by a clear margin. It leads in efficiency (21.3% vs 20.4%) and matches or exceeds on warranty (25 vs 25 years). For most residential installations, the Solaria PowerXT 430R is the stronger choice.
Key Differences
- • Silfab SIL-370-BK 370W is rated at 370W while Solaria PowerXT 430R is rated at 430W, a 60W difference.
- • Solaria PowerXT 430R achieves 21.3% efficiency vs 20.4% for the other, a 0.9 percentage point gap.
- • Both carry matching 25-year product warranties.
- • Solaria PowerXT 430R has a superior temperature coefficient of -0.34%/°C vs -0.35%/°C, retaining more power in hot climates.
- • Silfab SIL-370-BK 370W uses PERC Mono cells while Solaria PowerXT 430R uses Shingled Mono PERC cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The Solaria PowerXT 430R achieves 21.3% module efficiency compared to Silfab SIL-370-BK 370W's 20.4%, meaning Solaria PowerXT 430R converts 0.9 percentage points more sunlight into electricity per square meter. In practical terms, the Silfab SIL-370-BK 370W produces 189.5 watts per square meter of panel area while the Solaria PowerXT 430R produces 212.9 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 Solaria PowerXT 430R delivers 430W per panel versus 370W for the Silfab SIL-370-BK 370W, a 60W difference per module. To build an 8 kW residential system, you would need 22 Silfab SIL-370-BK 370W panels or 19 Solaria PowerXT 430R panels. Choosing the higher-wattage option saves 3 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 Solaria PowerXT 430R has a temperature coefficient of -0.34%/°C versus -0.35%/°C for the Silfab SIL-370-BK 370W. On a hot summer day when cell temperature reaches 65°C (40°C above the 25°C STC baseline), the Solaria PowerXT 430R retains 93.2% of its rated power while the other retains 93.0%. 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-370-BK 370W is backed by a 25-year product warranty and 25-year performance guarantee, while the Solaria PowerXT 430R 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-370-BK 370W; 1.5% first year then 0.4%/year for Solaria PowerXT 430R), after 25 years the Silfab SIL-370-BK 370W should retain approximately 89.4% of original output versus 88.9% for the Solaria PowerXT 430R. The end-of-life output levels are closely matched.
Physical Dimensions & Weight
The Silfab SIL-370-BK 370W measures 1722×1134×30mm and weighs 19.5 kg, while the Solaria PowerXT 430R measures 1879×1075×40mm at 22 kg. 1.95 m² of panel area for the Silfab SIL-370-BK 370W versus 2.02 m² for the Solaria PowerXT 430R. The Silfab SIL-370-BK 370W is 2.5 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 50 kg. Similar footprints mean both panels fit comparably on standard residential rooftop configurations.
Specification Comparison
| Specification | Silfab SIL-370-BK 370W | Solaria PowerXT 430R |
|---|---|---|
| Power | 370W | 430W |
| Efficiency | 20.4% | 21.3% |
| Power Density | 17.6 W/sq ft | 19.8 W/sq ft |
| Cell Type | PERC Mono | Shingled Mono PERC |
| Bifacial | No | No |
| Weight | 19.5 kg | 22 kg |
| Temp Coefficient | -0.35%/°C | -0.34%/°C |
| Snow Load | 2400 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% | 1.5% |
| Annual Degradation | 0.4% | 0.4% |
| Country | United States | USA |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: Solaria PowerXT 430RThe Solaria PowerXT 430R achieves 21.3% efficiency versus 20.4% — a 0.9 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 1.8 kW more total system capacity, or 9 kWh more annual production in an average US location.
2. Hot Climate Performance
Winner: Solaria PowerXT 430RThe Solaria PowerXT 430R has a better temperature coefficient of -0.34%/°C versus -0.35%/°C. On a 45°C summer day (20°C above STC), the winner retains 93.2% of rated power versus 93.0%. 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: Solaria PowerXT 430RThe Solaria PowerXT 430R delivers 430W versus 370W per panel — 60W more. For an 8 kW system, you need 19 panels with the higher-wattage option versus 22 panels, saving 3 panels and the associated racking and labor costs.
5. Cell Technology
Winner: TieThe Silfab SIL-370-BK 370W uses PERC Mono: PERC (Passivated Emitter Rear Cell) is the current mainstream technology, offering good efficiency at the lowest manufacturing cost. The Solaria PowerXT 430R uses Shingled Mono PERC: PERC (Passivated Emitter Rear Cell) is the current mainstream technology, offering good efficiency at the lowest manufacturing cost. Both are equivalent-generation technologies.
Silfab SIL-370-BK 370W
The SIL-370-BK is Silfab's entry-level US-made all-black panel delivering 370W for budget-conscious domestic installations.
Pros
- + Made in USA
- + All-black design
- + 25-year warranty
- + ARRA compliant
Cons
- - Lower wattage
- - Basic PERC technology
- - Less competitive efficiency
Solaria PowerXT 430R
The Solaria PowerXT 430R is a US-manufactured shingled-cell solar panel that eliminates traditional busbars and cell gaps to maximize active cell area and deliver a sleek, uniform all-black appearance. Shingled cell technology overlaps cell strips like roof shingles, reducing inactive area by approximately 50% compared to traditional half-cut designs. This results in more power from the same panel area and improved shade tolerance due to the shingled cell interconnection pattern. Made in Fremont, California, the PowerXT qualifies for domestic content bonus ITC credits.
Pros
- + Shingled cell technology — more power per square foot than traditional panels
- + Sleek all-black appearance with no visible busbars or cell gaps
- + Made in USA (Fremont, CA) — qualifies for domestic content ITC bonus
- + Enhanced shade tolerance from shingled interconnection pattern
- + 25-year product and performance warranties
- + No hot spots — shingled design eliminates busbar-related failures
Cons
- - Premium pricing for US-manufactured shingled technology
- - 430W is competitive but not class-leading for this panel size
- - Shingled cell technology has less field history than traditional designs
- - Limited to Solaria-authorized installer network
Choose Silfab SIL-370-BK 370W If...
- ✓ Government or institutional projects requiring ARRA/Buy America compliance.
Choose Solaria PowerXT 430R 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
- ✓ US homeowners who prioritize American-made panels with a premium all-black aesthetic and want domestic content ITC bonus eligibility.
Our Recommendation
We recommend the Solaria PowerXT 430R 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 Silfab SIL-370-BK 370W remains a good product, but the Solaria PowerXT 430R delivers better overall value for the majority of installations.
Frequently Asked Questions
Which is better, Silfab SIL-370-BK 370W or Solaria PowerXT 430R?
The Solaria PowerXT 430R wins this comparison by a clear margin. It leads in efficiency (21.3% vs 20.4%) and matches or exceeds on warranty (25 vs 25 years). For most residential installations, the Solaria PowerXT 430R is the stronger choice.
Which panel is more efficient, Silfab SIL-370-BK 370W or Solaria PowerXT 430R?
The Solaria PowerXT 430R at 21.3% module efficiency. Higher efficiency means more watts per square foot of roof space, which is critical for space-constrained installations. The difference of 0.9 percentage points translates to approximately 60W per panel under standard test conditions.
Which has a better warranty, Silfab SIL-370-BK 370W or Solaria PowerXT 430R?
The Silfab SIL-370-BK 370W comes with a 25-year product warranty and 25-year performance guarantee. The Solaria PowerXT 430R offers 25-year product and 25-year performance warranties. Both offer identical warranty terms.
Which panel performs better in hot weather?
The Silfab SIL-370-BK 370W has a temperature coefficient of -0.35%/°C and the Solaria PowerXT 430R is -0.34%/°C. Solaria PowerXT 430R 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-370-BK 370W vs Solaria PowerXT 430R panels do I need for an 8 kW system?
For an 8 kW system: you need 22 Silfab SIL-370-BK 370W panels (370W each) or 19 Solaria PowerXT 430R panels (430W each). The Solaria PowerXT 430R requires fewer panels, saving on racking hardware and installation labor.
Related Resources
Last updated: February 2026