Answer‑First Estimate
Installing a 15‑panel system typically costs between $9,000 and $14,000 before incentives, depending on panel type, installer, and local permits. After federal tax credits and state rebates, the net cost often falls to $5,500–$9,500. Below we break down the key components and provide a sample cost table so you can compare realistic scenarios.
- Answer‑First Estimate
- What Influences the Price?
- 1. Panel Quality and Efficiency
- 2. Inverter and Electrical Components
- 3. Installation Labor and Mounting Hardware
- 4. Permits, Inspection, and Grid Interconnection
- 5. Incentives and Rebates
- Sample Cost Table
- How to Get an Accurate Quote
- Long‑Term Value and Payback
- Key Takeaways
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What Influences the Price?
1. Panel Quality and Efficiency
Higher‑efficiency panels (e.g., 400–420 W each) deliver more power per square foot but can cost 10–20% more than standard 350 W panels. A 15‑panel array usually ranges from 5,250 W to 6,300 W.
2. Inverter and Electrical Components
Micro‑inverters or string inverters add to the cost. A 5‑kW inverter can cost $1,000–$2,000, while micro‑inverters add $50–$70 per panel.
3. Installation Labor and Mounting Hardware
Labor varies by region: $1,200–$2,500 for a 15‑panel roof‑mount installation. Mounting racks, racking hardware, and wiring also contribute $500–$1,000.
4. Permits, Inspection, and Grid Interconnection
Permit fees range from $100 to $800, plus inspection costs. Grid interconnection fees can add $200–$1,000 depending on utility policies.
5. Incentives and Rebates
Federal Investment Tax Credit (ITC) offers 30% off the total cost (as of 2026). Many states provide additional rebates ($500–$2,000). These incentives can reduce the effective price by up to 45%.
Sample Cost Table
| Attribute | Estimated Cost (USD) | Source Type |
|---|---|---|
| Panels (15 × 400 W) | $5,000 | Manufacturer quote |
| Inverter (5 kW) | $1,500 | Installer estimate |
| Mounting hardware & labor | $1,800 | Labor estimate |
| Permits & inspection | $500 | Municipal fee schedule |
| Installation total | $9,800 | Sum of above |
| Federal ITC (30%) | -$2,940 | IRS guidance |
| State rebate (average) | -$1,200 | State program list |
| Net cost after incentives | $5,660 | Calculated total |
How to Get an Accurate Quote
- Request detailed proposals from at least three licensed installers.
- Verify that quotes include all hardware, labor, permits, and potential tax credit calculations.
- Ask for a breakdown of panel wattage and expected system output.
Long‑Term Value and Payback
On average, a 5‑kW system saves $800–$1,200 annually in electricity bills. With a net cost of $5,660, the payback period is roughly 5–7 years, after which you enjoy free power and a lower carbon footprint.
Key Takeaways
• The pre‑incentive cost for 15 panels ranges $9,000–$14,000.
• After federal ITC and state rebates, the net cost typically falls to $5,500–$9,500.
• Local labor, permitting, and utility policies can shift the final price by up to 20%.
• A realistic payback period is 5–7 years, making it a worthwhile investment for most homeowners.