LONGi Solar — China
Hi-MO 420W B
The LONGi Solar Hi-MO 420W B is a 420W N-Type TOPCon solar panel with 20.2% efficiency. Backed by a 25-year warranty.
Standard TierFEOC: Restricted
420W
Wattage
20.2%
Efficiency
N-Type TOPCon
Cell Type
25 years
Warranty
Full Specifications
- Brand
- LONGi Solar
- Model
- Hi-MO 420W B
- Series
- Hi-MO
- Wattage
- 420W
- Module Efficiency
- 20.2%
- Cell Type
- N-Type TOPCon
- Dimensions
- 66-80" x 39-41"
- Weight
- 48 lbs
- Warranty
- 25 years
- Est. Price Per Watt
- $2.14
- Est. 7kW System Cost
- $14,980
- Est. 10kW System Cost
- $21,400
- Temperature Coefficient
- -0.25%/°C
- Bifacial
- No
- Origin
- China
- FEOC Status
- fail
Other LONGi Solar Panels
| Model | Wattage | Efficiency | Cell | $/W |
|---|---|---|---|---|
| Hi-MO 480W D | 480W | 22.1% | N-Type TOPCon | $2.67 |
| Hi-MO 475W C All-Black | 475W | 22% | PERC | $2.64 |
| Hi-MO 465W B BF | 465W | 21.7% | N-Type TOPCon | $2.56 |
| Hi-MO 465W E Pro | 465W | 21.7% | PERC | $2.56 |
| Hi-MO 460W A HC | 460W | 21.5% | PERC | $2.50 |
Similar Wattage Panels (Competitors)
| Panel | Wattage | Efficiency | $/W |
|---|---|---|---|
| Maxeon 3 450W D Plus | 450W | 23.3% | $4.61 |
| SunPower Maxeon 445W D Plus | 445W | 23.1% | $4.58 |
| Maxeon 3 445W A Ultra | 445W | 23.1% | $4.51 |
| SunPower Maxeon 440W C | 440W | 22.9% | $4.50 |
Frequently Asked Questions
How much does a 420W LONGi Solar Hi-MO 420W B cost?
The LONGi Solar Hi-MO 420W B costs approximately $899 per panel ($$2.14/W). A typical 7kW system using this panel would cost around $14,980 before incentives.
⚠ The 30% federal solar tax credit has ended — Section 25D expired December 31, 2025, and the Section 48E construction-start deadline passed July 4, 2026.
Selecting 30% ITC assumes you began construction before this deadline. Most new purchases no longer qualify.Learn about your options after the deadline →
Is the LONGi Solar Hi-MO 420W B a good solar panel?
The LONGi Solar Hi-MO 420W B has 20.2% efficiency and a 25 years warranty, placing it in the standard tier. This is a solid mid-range panel suitable for most residential installations.
How many LONGi Solar Hi-MO 420W B panels do I need?
For a typical 7kW residential system, you'd need approximately 17 panels. For a 10kW system, plan for about 24 panels. The exact number depends on your roof space, energy usage, and local sun hours.