First Solar — US
Series 4 405-D Max
The First Solar Series 4 405-D Max is a 405W CdTe solar panel with 18.2% efficiency. Made in US. Backed by a 25-year warranty.
Premium Tier🇺🇸 Domestic Content Bonus Eligible
405W
Wattage
18.2%
Efficiency
CdTe
Cell Type
25 years
Warranty
Full Specifications
- Brand
- First Solar
- Model
- Series 4 405-D Max
- Series
- Series 4
- Wattage
- 405W
- Module Efficiency
- 18.2%
- Cell Type
- CdTe
- Dimensions
- 66-80" x 39-41"
- Weight
- 46 lbs
- Warranty
- 25 years
- Est. Price Per Watt
- $2.60
- Est. 7kW System Cost
- $18,200
- Est. 10kW System Cost
- $26,000
- Temperature Coefficient
- -0.25%/°C
- Bifacial
- No
- Origin
- US
- FEOC Status
- pass
Other First Solar Panels
| Model | Wattage | Efficiency | Cell | $/W |
|---|---|---|---|---|
| Series 6 475W E Pro | 475W | 20.5% | CdTe | $3.75 |
| Series 7 475W E Pro | 475W | 20.5% | CdTe | $3.75 |
| Series 4 475W E Pro | 475W | 20.5% | CdTe | $3.75 |
| Series 5 475W E Pro | 475W | 20.5% | CdTe | $3.75 |
| Series 6 465W D Plus | 465W | 20.2% | CdTe | $3.60 |
Similar Wattage Panels (Competitors)
| Panel | Wattage | Efficiency | $/W |
|---|---|---|---|
| SunPower Maxeon 435W A Ultra | 435W | 22.7% | $4.42 |
| SunPower Performance 435W A Ultra | 435W | 22.7% | $4.42 |
| SunPower X-Series 435W A Ultra | 435W | 22.7% | $4.42 |
| SunPower E-Series 435W A Ultra | 435W | 22.7% | $4.42 |
Frequently Asked Questions
How much does a 405W First Solar Series 4 405-D Max cost?
The First Solar Series 4 405-D Max costs approximately $1053 per panel ($$2.60/W). A typical 7kW system using this panel would cost around $18,200 before incentives.
⚠ The 30% Federal Solar Tax Credit (48E/ITC) expired 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 First Solar Series 4 405-D Max a good solar panel?
The First Solar Series 4 405-D Max has 18.2% efficiency and a 25 years warranty, placing it in the premium tier. This is a solid mid-range panel suitable for most residential installations. It also qualifies for the domestic content bonus under the Inflation Reduction Act.
How many First Solar Series 4 405-D Max panels do I need?
For a typical 7kW residential system, you'd need approximately 18 panels. For a 10kW system, plan for about 25 panels. The exact number depends on your roof space, energy usage, and local sun hours.