The short answer: price per watt installed. System size (kW × 1,000) × per-watt rate = gross install price. Per-watt rates in 2026 typically run $3.00-$5.00 depending on region, cash vs financed, and material tier. An 8 kW system at $3.50/W = $28,000 gross; after 30% federal ITC = $19,600 net.
The pricing formula
Gross install price = system size (W) × per-watt rate × tier markup
- System size in watts (typically 6,000-12,000 W for residential).
- Per-watt rate covers panels + inverters + racking + electrical + install labor + margin.
- Tier markup for premium components, battery storage, financing dealer fees.
- Federal 30% ITC applied at tax filing — show on the customer-facing quote.
- Net out-of-pocket = gross − ITC.
Typical per-watt rates by deal type and region
| Deal type | Per-watt range | Notes |
|---|---|---|
| Cash install — Sunbelt suburbs | $2.80-$3.40/W | Lower labor + competition |
| Cash install — major metros | $3.20-$3.80/W | Balanced |
| Cash install — coastal/high-cost | $3.60-$4.40/W | Higher labor + willingness to pay |
| Financed install (loan/lease/PPA) | $3.50-$5.00/W | Adds 20-30% dealer fee |
| Premium tier (Tier 1 panels + microinverters) | +$0.30-$0.60/W | Closing argument for premium homes |
| Battery storage paired | +$0.80-$1.20/W storage | Add to base per-watt |
The ITC math homeowners care about
Most residential solar customers want to see two prices: gross and net-after-ITC. Solar Launch's customer portal renders both automatically on every quote, with the 30% ITC explicitly itemized (current through 2032 per IRS rules).
Example: 9 kW system at $3.50/W = $31,500 gross. ITC of 30% = $9,450. Net out-of-pocket = $22,050. The homeowner sees the $22K number alongside the rendered roof and the 25-year savings projection.
Cash vs financed — always show both
The single biggest residential solar pricing mistake is quoting only one financing path. Cash buyers close at $2.80-$3.40/W; financed buyers need $3.50-$5.00/W to absorb dealer fees. Most homeowners want to see both numbers to decide which path makes sense — pulling the financing option off the table loses deals.
The customer portal can show: Cash price · Loan monthly payment (with selected partner) · Lease or PPA monthly (where offered) — homeowners self-qualify and pick their path.
Target gross margin
A healthy residential solar business runs 15-25% gross margin on install. The upper end is driven by efficient install crews, in-house electricians, low broker-lead dependency, and direct relationships with panel + inverter distributors. New installers running broker leads in year 1 typically run 5-12% gross until they migrate to direct acquisition (mailed quotes + warm follow-up D2D).
The fastest quote workflow
- Render the roof in Solar Launch's Render Agent (~30 seconds).
- Read the auto-calculated system size from Google Solar API (within 5-10% of engineered design).
- Apply your per-watt rate (set once in account settings). Gross, ITC-net, and financed prices auto-populate.
- Send the customer portal link or mail the postcard. Homeowner sees all prices, picks the path, pays a refundable site-survey deposit.
End-to-end, this is about 60 seconds per home from address to deposit-eligible quote. See solar pricing guide for deeper detail.
Quote any solar job in under a minute.
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