How to check a solar quote: six numbers to verify
Before you sign anything, run these six checks with me.
Divide the price by the system size, compare production with public estimates, confirm which export credit the savings use, remove any federal credit, know who owns the system, and look up the installer's record and license.
Compare two or three quotes
The easiest way to check one quote is to get another. Enter your ZIP:
1. Price per watt
Price per watt = quote price before incentives ÷ (system size in kW × 1,000). A $16,000 quote for 7 kW is $2.29/W.
- Phoenix: average $2.28/W; a typical 13.9 kW system is quoted $26,915–$36,415 (EnergySage, updated 2026-09-04).
- Tucson: average $2.26/W; a typical 12.2 kW system is quoted $23,381–$31,633 (EnergySage, updated 2026-09-04).
- San Antonio: average $2.20/W; a typical 13.8 kW system is quoted $25,749–$34,837 (EnergySage, updated 2026-09-04).
- Austin: average $2.25/W; a typical 11.9 kW system is quoted $22,674–$30,676 (EnergySage, updated 2026-09-04).
- San Diego: average $2.56/W; a typical 6.7 kW system is quoted $14,464–$19,568 (EnergySage, updated 2026-09-04).
- Fresno: average $2.70/W; a typical 8.8 kW system is quoted $20,267–$27,419 (EnergySage, updated 2026-09-04).
2. Production estimate
NREL PVWatts estimates for a fixed south-facing roof at 20°. If a quote promises much more, ask what orientation, shading and losses it assumes.
| Area | kWh a year per kW | 7 kW system, kWh a year |
|---|---|---|
| Phoenix, AZ | 1,755 | 12,285 |
| Tucson, AZ | 1,788 | 12,516 |
| San Antonio, TX | 1,503 | 10,521 |
| Austin, TX | 1,483 | 10,381 |
| San Diego, CA | 1,716 | 12,012 |
| Fresno, CA | 1,654 | 11,578 |
3. Export credit
Power you use at home saves the full energy charge; power sent to the grid earns the utility's export credit, which is usually far lower. Ask which rate the savings estimate uses.
| Utility | Area | Export credit | Program |
|---|---|---|---|
| Arizona Public Service | Phoenix | 5.55¢/kWh | Rate Rider RCP |
| Salt River Project | Phoenix | 3.45¢/kWh | Customer generation export price plans (E-13 Time-of-Use Export, E-14 EV Export) |
| Tucson Electric Power | Tucson | 5.13¢/kWh | Rider R-14 Resource Comparison Proxy |
| CPS Energy | San Antonio | no single rate (hourly values) | Rider E5 net metering (monthly netting kWh for kWh; Net Excess Generation credited at CPS avoided energy cost, carried forward, no cash payout) |
| Austin Energy | Austin | 9.91¢/kWh | Value of Solar Rider (all production credited, charges for all consumption) |
| San Diego Gas & Electric | San Diego | no single rate (hourly values) | Net Billing Tariff (Avoided Cost Calculator export values) |
| Pacific Gas & Electric | Fresno | no single rate (hourly values) | Solar Billing Plan (Schedule NBT): Energy Export Credit at hourly Avoided Cost Calculator values; residential customers must take the E-ELEC (Electric Home) rate |
4. No federal credit in the price
The 30% federal credit is not available for property placed in service after December 31, 2025 (IRS). If the net price subtracts it, ask for a corrected quote. What changed.
5. Purchase, loan, lease or PPA
With a lease or PPA the company owns the system and you pay monthly or per kWh. Ask about yearly price increases, what happens if you sell the home, and who maintains the system.
- Phoenix: 11% of systems in 2022–2023 records were leased or under a PPA.
- Austin: 0% of systems in 2022–2024 records were leased or under a PPA.
- San Diego: 18% of systems in 2022–2023 records were leased or under a PPA.
- Fresno: 29% of systems in 2022–2023 records were leased or under a PPA.
Get more quotes for your home
Enter your ZIP to request quotes from installers in your area.
6. The company's record and license
Our city pages show how many systems each company connected locally, since when, and what share were leased. Then check the license:
- Arizona: Arizona Registrar of Contractors
- California: California Contractors State License Board
Run the numbers
Enter your ZIP, price and size to get price per watt and payback with your utility's rates.
Updated 2026-09-15.