SunPower — US
Maxeon 390W B Plus
The SunPower Maxeon 390W B Plus is a 390W IBC solar panel with 21.2% efficiency. Made in US. Backed by a 25-year warranty.
Discontinued panel — still supported for existing owners. SunPower ceased operations (Chapter 11 bankruptcy, August 2024) Specs below reflect the final production version.
Premium Tier🇺🇸 Domestic Content Bonus EligibleBifacial
390W
Wattage
21.2%
Efficiency
IBC
Cell Type
25 years
Warranty
Full Specifications
- Brand
- SunPower
- Model
- Maxeon 390W B Plus
- Series
- Maxeon
- Wattage
- 390W
- Module Efficiency
- 21.2%
- Cell Type
- IBC
- Dimensions
- 65-67" x 39-40"
- Weight
- 44 lbs
- Warranty
- 25 years
- Est. Price Per Watt
- $3.79
- Est. 7kW System Cost
- $26,530
- Est. 10kW System Cost
- $37,900
- Temperature Coefficient
- -0.25%/°C
- Bifacial
- Yes
- Origin
- US
- FEOC Status
- pass
Other SunPower Panels
| Model | Wattage | Efficiency | Cell | $/W |
|---|---|---|---|---|
| Maxeon 455W E Pro | 455W | 23.4% | IBC | $4.71 |
| Maxeon 445W D Plus | 445W | 23.1% | IBC | $4.58 |
| Maxeon 440W C | 440W | 22.9% | IBC | $4.50 |
| Maxeon 435W A Ultra | 435W | 22.7% | IBC | $4.42 |
| Maxeon 430W E Max | 430W | 22.6% | IBC | $4.38 |
Similar Wattage Panels (Competitors)
| Panel | Wattage | Efficiency | $/W |
|---|---|---|---|
| Panasonic HIT 420W D Plus | 420W | 22.3% | $4.08 |
| Panasonic HIT 420W A Ultra | 420W | 22.3% | $4.08 |
| Maxeon 3-42 HC | 420W | 22.1% | $3.98 |
| Panasonic HIT 415W C | 415W | 22% | $3.94 |
Frequently Asked Questions
How much does a 390W SunPower Maxeon 390W B Plus cost?
The SunPower Maxeon 390W B Plus costs approximately $1478 per panel ($$3.79/W). A typical 7kW system using this panel would cost around $26,530 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 SunPower Maxeon 390W B Plus a good solar panel?
The SunPower Maxeon 390W B Plus has 21.2% efficiency and a 25 years warranty, placing it in the premium tier. This is above-average efficiency, making it a strong choice. It also qualifies for the domestic content bonus under the Inflation Reduction Act.
How many SunPower Maxeon 390W B Plus panels do I need?
For a typical 7kW residential system, you'd need approximately 18 panels. For a 10kW system, plan for about 26 panels. The exact number depends on your roof space, energy usage, and local sun hours.