Cornerstone guide · updated 2026-08-21
How to Compare Solar Quotes Without Getting Misled
Three quotes for the same roof can differ by 20–30%. Here is how to compare them fairly.
Step 1 — Normalize everything to $/W
Ask every installer for the cash price and the system size in watts. Divide: price ÷ watts = $/W. This removes the size confounder. If one quote is 9.6 kW and another is 10 kW, comparing totals is meaningless — comparing $/W is not. Use the quote comparison tool to do this across three quotes at once.
Step 2 — Separate the battery from the solar
A quote with a $13,500 battery will look expensive against one without. Compare solar-only $/W (total minus battery line, divided by watts), then evaluate the battery separately at $/kWh installed ($1,000–$2,000/kWh typical). A battery is a purchase decision of its own — see battery economics.
Step 3 — Get the exact equipment in writing
Demand, on the quote: panel model (brand + exact model), inverter model, and racking. “Premium panels” or “Q CELLS” without a model number is marketing, not a spec. Look up each model in our panel database — wattage, efficiency, and warranty terms are verifiable.
Step 4 — Scrutinize the production claim
Every quote should state estimated annual production in kWh and the tool used to model it (PVWatts, Aurora, etc.). Production is what your savings are built on. If two quotes claim wildly different kWh for the same roof, the higher one isn’t “better” — it may be inflated to make the deal look better. Reasonable estimates for your state are on the state pages.
Step 5 — Separate financing from pricing
A financed price is not comparable to a cash price. Financed quotes usually embed a dealer fee of 15–30% in the principal to subsidize a low APR. Ask every lender three questions: (1) cash price, (2) dealer fee %, (3) APR and term. Then run the financing calculator. And in 2026, there is no federal credit to “apply” to a financed price — if a quote says otherwise, question it.
Step 6 — Read the warranty table
Solar warranties are not one “25-year warranty.” There are four, and they cover different things:
| Warranty | Covers | Typical term |
|---|---|---|
| Panel product | Manufacturing defects (panel fails) | 12–25 yrs (Maxeon: 40) |
| Panel performance | Output stays above a % (e.g., 87–92% at year 25) | 25–40 yrs |
| Inverter | Inverter failure | 5–25 yrs (micros usually 25) |
| Workmanship | Installer’s labor and roof penetrations | Typically 10–25 yrs |
Battery warranties add cycle terms (e.g., 70% capacity after 10 years). Ask who honors the workmanship warranty if the installer goes out of business — a real risk in solar, and worth a question, not a scare.
Step 7 — Check the red flags
- No equipment models listed.
- No production estimate.
- Price “includes” a 30% federal tax credit (expired for 2026).
- “Free solar” or “zero bill guaranteed” language.
- Same-day signing bonus or “price only valid today.”
- Financed quote without a stated dealer fee or cash price.
- Escalators above ~3%/yr on a lease/PPA.
- Pressure to sign before you’ve compared quotes.
None of these alone proves fraud — but each is a reason to slow down. See our red-flag policy (we don’t name companies without evidence).
Step 8 — Judge the installer, not just the price
Years operating, licensing, certifications, how warranties are serviced, and whether the equipment brands have independent support. The cheapest quote is not “best” — it’s the start of the conversation. Use the quote analyzer to understand where each price sits, then ask the installers to explain the difference. That conversation is where the real comparison happens.
Rule of thumb: compare cash $/W first, production second, warranty third, installer fourth — and financing last, only after the cash price is known.