Start with the job, not the monthly payment
A solar quote is a bundle: hardware, labor, incentives, financing, and a savings story. The monthly number is one output of those inputs. If you only compare monthly payments, you are comparing the wrapping, not the box.
This guide is for a homeowner who already has a proposal. It is not a shopping list for finding an installer.
Read these five blocks first
Most residential proposals bury the useful parts in different places. Pull these into one list before you compare anything:
- System size in kilowatts, and the yearly energy estimate in kilowatt-hours.
- Cash price, financed price, and whether those two numbers match.
- Named panel, inverter, and battery models — not just brand names.
- The utility-rate assumption used to forecast savings.
- Who the contractor of record is, and whether a license number is on the page.
Price is not the same as payment
Cash price is what the installation costs without a loan. A financed purchase may add a dealer fee, a financing charge included in the amount borrowed. Interest adds to what you repay over time. Ask for each cost separately, even if the quoted cash and financed prices match.
Savings depend on assumptions you can name
Production, utility-rate growth, incentives, and how much of your bill the system actually offsets all move the savings line. Two honest quotes can disagree. Two dishonest ones can look generous for the same reason: they assumed a sunnier roof, a faster-rising bill, or a tax credit that has expired.
Check each incentive’s current eligibility and timing requirements before counting it toward your savings. A benefit that does not apply to your purchase makes the quoted net cost look too low.
When a second read is worth it
If the quote is large relative to your comfort, if two proposals disagree, or if you cannot tell cash from financed cost, an independent review is the cheaper hour. BidProof’s Bid Review is $49.
A practical first pass through your proposal
Illustrative example: a proposal lists an 8 kW system and a $28,000 cash price. That is 8,000 watts and $3.50 per watt before incentives. If $4,000 of that price is a separate roof repair, ask for the solar-only subtotal before comparing it with another bid.
The CFPB documents loan markups that can raise financed prices above cash prices. Comparing the two totals is a useful first check. CFPB: Solar Financing (U.S. market report, August 2024; not a current tax-eligibility source)
The IRS says the residential clean energy credit is unavailable for property placed in service after December 31, 2025. Confirm the applicable rule before counting a federal credit in a new proposal. IRS: Residential Clean Energy Credit (U.S. federal rules; accessed September 18, 2026)
- Write down the cash price before incentives and separate any non-solar work.
- Record system size in kW DC and estimated annual production in kWh.
- Request the financing disclosures and a schedule of payments.
- Mark assumptions you cannot trace to a document, tariff, or named source.
- Take those questions back to the seller before deciding.