Silfab SIL-370-BK 370W Specifications & Review
The SIL-370-BK is Silfab's entry-level US-made all-black panel delivering 370W for budget-conscious domestic installations.
What Makes the Silfab SIL-370-BK 370W Different
The Silfab SIL-370-BK 370W is manufactured in North America by Silfab Solar, making it one of the few solar panels that qualifies as FEOC-compliant (Foreign Entity of Concern free) under the Inflation Reduction Act. This means the SIL-370-BK 370W qualifies for the full 30% ITC plus potential domestic content bonus credits, which can push total incentives to 40-50%. Silfab operates manufacturing facilities in the state of Washington and Ontario, Canada, using automated production lines that meet rigorous quality standards. At 370W and 20.4% efficiency with 108 PERC Mono cells, the panel delivers strong performance. The 1722×1134mm footprint at 19.5 kg is designed for residential rooftops. Silfab's 25-year product and 25-year performance warranty with 0.4% annual degradation provide competitive coverage from a domestic manufacturer.
Key Specifications
| Brand | Silfab |
| Model | Silfab SIL-370-BK 370W |
| Power Output | 370W |
| Efficiency | 20.4% |
| Power Density | 17.6 W/sq ft |
| Cell Type | PERC Mono |
| Cell Count | 108 cells |
| Dimensions | 1722 x 1134 x 30 mm |
| Weight | 19.5 kg |
| Open Circuit Voltage (Voc) | 38V |
| Max Power Voltage (Vmp) | 32V |
| Short Circuit Current (Isc) | 12.49A |
| Max Power Current (Imp) | 11.56A |
| Temp Coefficient (Pmax) | -0.35%/°C |
| Product Warranty | 25 years |
| Performance Warranty | 25 years |
| First Year Degradation | 1% |
| Annual Degradation | 0.4% |
| Country of Manufacture | United States |
| Certifications | IEC 61215, IEC 61730, UL 1703 |
| Snow Load | 2400 Pa (50.1 psf) |
| Wind Load | 2400 Pa (50.1 psf) |
Pros & Cons
Pros
- ✓ Made in USA
- ✓ All-black design
- ✓ 25-year warranty
- ✓ ARRA compliant
Cons
- ✗ Lower wattage
- ✗ Basic PERC technology
- ✗ Less competitive efficiency
Best For
Government or institutional projects requiring ARRA/Buy America compliance.
Is the Silfab SIL-370-BK 370W Worth It?
The Silfab SIL-370-BK 370W delivers 370W of power at 20.4% module efficiency, which is near the current industry average of approximately 21%. While not the highest-efficiency option on the market, it may offer compelling value depending on price and your available roof space.
From a warranty perspective, the SIL-370-BK 370W 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.
Pricing varies by region and installer, but the SIL-370-BK 370W's combination of 20.4% efficiency and 25-year warranty should be weighed against per-watt quotes from your installer. Request at least three quotes to ensure you are getting competitive pricing for this tier of panel.
For hot climates, the temperature coefficient of -0.35%/°C is average. This is on the higher end, meaning noticeable power reduction when temperatures climb well above 25°C (77°F). If you live in a consistently hot climate, consider a panel with a lower temperature coefficient. Overall, the Silfab SIL-370-BK 370W can be a reasonable choice depending on your budget and performance requirements.
Real-World Performance
In real-world conditions, the Silfab SIL-370-BK 370W delivers consistent energy production shaped by its -0.35%/°C temperature coefficient. On a hot summer day when panel surface temperatures reach 65°C (40°C above STC), the SIL-370-BK 370W loses approximately 14.0% of rated output — typical for PERC technology. Over a full year in a typical US location, expect annual specific yield of 1,400-1,700 kWh per kW installed, depending on location, tilt, and shading. The 1% first-year degradation settles into 0.4% annual degradation thereafter; after 25 years the SIL-370-BK 370W should still produce approximately 89.4% of its original rating. The 108 half-cut cells provide improved shade tolerance compared to full-cell designs — when one cell is shaded, only one sub-string is affected rather than an entire string, limiting production losses to approximately one-third of the panel rather than one-half.
Who Should Buy the Silfab SIL-370-BK 370W?
System Design Tips
For string inverter systems, the Silfab SIL-370-BK 370W's Voc of 38V allows up to 15 panels per string on a 600V inverter, or 12 panels per string on 480V systems. The Isc of 12.49A is within the input range of all major residential string inverters and microinverters. For microinverter pairing, the Enphase IQ8A (366VA) or IQ8H (384VA) handles the 370W output well with a DC/AC ratio of 1.0-1.0. SolarEdge P505 optimizers pair well for optimizer-based systems. Size your inverter at 75-90% of total DC wattage for optimal clipping management — for a 28-panel array (10.4 kW DC), a 8 W AC inverter is a good match. The panel handles 2400 Pa snow load and 2400 Pa wind load.
Price Estimate
The Silfab SIL-370-BK 370W is sold through residential solar distributors and installers. Silfab pricing varies by distributor and order volume. For a 28-panel system (10.4 kW DC), total installed cost including panels, inverter, racking, wiring, permitting, and labor typically runs $2.50-3.50/W, or approximately $31,080-$36,260 before the 30% federal ITC. After ITC: approximately $21,756-$25,382. Domestic content bonus credits under IRA may reduce costs further.
How the Silfab SIL-370-BK 370W Compares
| Model | Wattage | Efficiency | W/sq ft | Warranty | Snow Load | Cell Type |
|---|---|---|---|---|---|---|
| Silfab SIL-370-BK 370W (this panel) | 370W | 20.4% | 17.6 | 25 yrs | 2400 Pa | PERC Mono |
| Q CELLS Q.PEAK DUO 370W | 370W | 20.4% | 17.6 | 12 yrs | 5400 Pa | PERC Mono |
| Aptos Solar DNA-120-MF26 370W | 370W | 20.28% | 18.6 | 25 yrs | 5400 Pa | PERC Mono |
| Aptos Solar DNA-120-BF26 370W | 370W | 20.28% | 18.6 | 25 yrs | 5400 Pa | PERC Mono Bifacial |
Compare This Panel
Installation & Compatibility
System Voltage & String Sizing
- Open Circuit Voltage (Voc)
- 38V
- Max Power Voltage (Vmp)
- 32V
- Short Circuit Current (Isc)
- 12.49A
- Max Power Current (Imp)
- 11.56A
- Max Panels per String (600V)
- 15 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
- 19.5 kg (43.0 lbs)
- Area per Panel
- 21.0 sq ft
- Weight per sq ft
- 2.0 lbs/sq ft
Recommended Inverter Types
- - Microinverters: Ideal for shaded roofs or complex layouts. Match to panels rated 370W+.
- - String Inverters: Cost-effective for unshaded arrays. Ensure MPPT range covers 32V.
- - Hybrid Inverters: Best if adding battery storage. Check DC input specs match panel Voc of 38V.
Frequently Asked Questions
How efficient is the Silfab SIL-370-BK 370W compared to other panels?
The SIL-370-BK 370W achieves 20.4% module efficiency, which is standard for PERC residential panels. PERC panels typically range from 20.0% to 21.8%, and the SIL-370-BK 370W delivers standard performance within that range. Higher efficiency means more watts per square foot of roof space.
What is the warranty on the Silfab SIL-370-BK 370W?
Silfab provides a 25-year product warranty covering manufacturing defects and a 25-year performance warranty guaranteeing output levels. The performance warranty typically starts at 99% after year 1 and degrades by 0.4% per year, guaranteeing approximately 89.4% output at year 25. The extended product warranty coverage exceeds the industry standard of 10-12 years.
How many Silfab SIL-370-BK 370W panels do I need for my home?
For a typical US home using 10,000 kWh per year, you need approximately 28 panels (10.4 kW system) assuming 4-5 peak sun hours per day. This varies significantly by location — homes in Arizona may need 25-27 panels while homes in the Pacific Northwest may need 30-32 panels. Your installer will calculate the exact number based on your utility bills, roof orientation, shading, and local solar resource.
What is the efficiency of the Silfab SIL-370-BK 370W?
The Silfab SIL-370-BK 370W achieves 20.4% module efficiency using PERC Mono cell technology. This is around the industry average for residential solar panels in 2026.
What warranty does the Silfab SIL-370-BK 370W 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 Silfab SIL-370-BK 370W perform in hot weather?
With a temperature coefficient of -0.35%/°C, the SIL-370-BK 370W experiences moderate power reduction in high temperatures. Every degree above 25°C reduces output by 0.35%.
What size system can I build with the Silfab SIL-370-BK 370W?
At 370W per panel, you would need approximately 22 panels for an 8 kW system or 28 panels for a 10 kW system. Each panel measures 1722 x 1134 mm (21.0 sq ft).
What inverter is best with the Silfab SIL-370-BK 370W?
The Silfab SIL-370-BK 370W works well with both string inverters and microinverters. For string inverters, choose one with a maximum input voltage above 38V and an MPPT voltage range that covers 32V. Microinverters rated for 370W+ 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 Silfab SIL-370-BK 370W last?
The Silfab SIL-370-BK 370W 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 Silfab SIL-370-BK 370W good for Arizona and other sunny states?
The Silfab SIL-370-BK 370W can work in hot states like Arizona, Nevada, and Texas, though its temperature coefficient of -0.35%/°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 Silfab SIL-370-BK 370W worth the money?
The Silfab SIL-370-BK 370W delivers 20.4% efficiency, which is near the industry average of ~21%. Combined with a industry-leading 25-year product warranty and 25-year performance guarantee, it offers reasonable value for homeowners seeking reliable solar generation.
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Last updated: February 2026