How to compare solar quotes

The short answer

Two quotes are only comparable when they describe the same system on the same terms. Ask each installer to price the same size, equipment and warranty, then compare them line by line rather than by the headline number. The checklist below follows the order most people find easiest.

Key takeaways

• Divide each total price by the system size in watts to get price per watt, and compare only quotes for similar systems.
• Ask for the cash price. On a solar loan, the amount you borrow can be well above it.
• Get production, warranties, permits and interconnection in writing.
• Check the installer’s license with your state before you sign anything.

1. Price per watt, and what it hides

Price per watt is the total price divided by system size in watts. It lets you compare a 6 kW quote with a 9 kW quote. Here is a purely illustrative example, not a market price. A quote of $24,000 for an 8 kW system (8,000 W) works out to $3.00 per watt. A quote of $22,400 for a 7 kW system (7,000 W) is $3.20 per watt, even though the dollar total is lower.

Price per watt is a starting point, not a verdict. It does not show whether the equipment is better, whether the panels will be shaded, or whether the quote includes a battery, roof work or panel upgrades. To see how a quote compares with typical installed costs for your utility, start with your utility page or the methodology for where RayValue’s cost ranges come from.

2. Same system, same equipment

Ask each installer to quote the same system size, or two sizes that you choose, and to list the panel make and model, the inverter type and any battery. The U.S. Department of Energy’s homeowner guide recommends getting a custom estimate from an installer after a rough check of your own, and it points to NABCEP certification as an industry standard for installer credentials. Ask whether the installer holds it and who will actually be on your roof.

If you want a battery, ask for it as a separate line so you can compare the solar-only price and the battery price on their own. In Florida, our reasoning (not a measured result) is that a battery may add more backup power than bill savings, so price it on its own. See the Florida calculator and battery costs and backup.

3. Production estimate

The expected annual kilowatt-hours is what turns a price into savings. The FTC advises getting detailed written bids that state expected output, and treating projected savings cautiously because future utility rates are hard to predict. The DOE guide points to the free PVWatts tool for a rough production estimate for your address.

Ask each installer what roof direction, tilt and shading they assumed, and what the guarantee is, if any. A guaranteed minimum output with a stated remedy is worth more than an estimate. If two installers quote the same size on the same roof and their production figures differ a lot, ask why. Our calculators use PVWatts too, so you can see a range for your ZIP code first.

4. Financing: APR, dealer fees and the cash price

Financing is where quotes differ most, and where the headline number misleads most often.

Loans. In an August 2024 report, the Consumer Financial Protection Bureau (CFPB) said stated APRs on solar-specific loans typically run from 1 to 7 percent and loan terms from 8 to 25 years. It also said many solar lenders add fees, called “dealer fees,” “platform fees” or similar names, that raise the loan principal above the cash price. According to the CFPB, these fees typically range from 10 to 30 percent of the cash price and can exceed 50 percent. Because they are folded into the principal, the stated APR can look lower than the true cost of borrowing.

The CFPB’s own example: a project with a $30,000 cash price and a 30 percent fee ($9,000) produces a loan principal of $39,000 plus interest. The same report says lenders often leave these fees out of the total cost of credit they show you.

What to ask:

• What is the cash price, with no financing?
• What is the loan principal, and is any fee included in it?
• What is the APR, and does it include all fees?
• Is there a payment that rises after a set period, or a prepayment you must make to keep the payment low?

The CFPB advisory also suggests asking for the cash price, comparing proposals from multiple installers and lenders, and considering a loan from a bank or credit union to bring to the installer.

Leases and PPAs. With a lease you pay a monthly amount. With a power purchase agreement (PPA) you pay per kilowatt-hour the system produces. The FTC says these contracts typically run long-term, citing 20 years as a common length, and that lease payments may rise over time. The CFPB report puts PPA price escalators at 1 to 5 percent a year and PPA terms at 6 to 25 years. Ask for the first-year price, the escalator, what happens if you sell, and what it costs to end the contract early. Our solar lease vs buy guide goes through the trade-offs.

5. Do not count on the federal tax credit

The federal residential clean energy credit (Section 25D) is not available for property placed in service after December 31, 2025, according to the IRS, so no 2026 quote should reduce the price by it. The CFPB warns that some sellers subtract a projected tax credit from the loan amount shown to you, which makes the price look smaller than what you borrow. If a quote shows a “net cost” after a federal credit, ask for the price without it. See solar without the federal tax credit and is solar worth it without the tax credit.

6. Warranties

Equipment and workmanship are covered separately. The FTC advises checking the warranties on the equipment and the installation work, and says a bid should state what each covers and for how long. Ask:

• How long is the panel warranty, the inverter warranty and the battery warranty (if any)?
• How long is the installer’s workmanship warranty, including roof penetrations?
• If the roof needs repair after installation, who pays?
• Who honors the workmanship warranty if the installer closes?

The DOE guide does not set out warranty terms, so get them in writing from the installer and the equipment makers.

7. Permits and interconnection

A good quote says who pulls the permits and whether permit fees are included; the FTC lists permit fees as part of the full installation cost. The DOE guide notes that a qualified installer should meet local building, fire and electrical codes, and that a certified electrician inspects the system during installation.

Interconnection is the utility’s approval to connect your system to the grid. Neither the FTC nor the DOE page covers interconnection, so ask each installer who files the application, whether there is a fee, and who is responsible if it is delayed. Both pages do cover net metering, and the DOE page says to check with your local utility, since rules differ by utility. For rules in your area, see the page for FPL, Duke Energy Florida, TECO, PG&E, SCE or SDG&E.

8. License, insurance and complaints

Check the license before you compare prices, since an unlicensed bid is not comparable.

• Florida. Florida law defines a solar contractor as one whose work covers installing, altering, repairing, maintaining, relocating or replacing potable solar water heating, pool solar heating and photovoltaic systems, plus their appurtenances (Florida Statutes s. 489.105). Look the company up on the Florida DBPR license search, and make sure the name on the contract matches the licensed business.
• California. The Contractors State License Board lists a C-46 Solar Contractor classification that covers installing, modifying, maintaining and repairing solar systems. Check the license on the CSLB site.

The FTC also advises checking a company’s record with consumer protection agencies and your state licensing board, searching its name with “complaints” or “reviews,” and walking away from anyone who pressures you to decide fast or sign before you can read the contract.

9. Payment schedule

In California, a CSLB bulletin from November 2022 (we have not checked for later changes to the law) says home improvement contracts, including residential solar, may require a down payment of no more than $1,000 or 10 percent of the contract price, whichever is less, and later payments cannot exceed the value of the work and materials delivered. If a California quote asks for more up front, that is a red flag. For Florida, we have not verified a comparable rule, so ask the installer to put the payment schedule in writing and tie each payment to a stage of work.

Next steps

1. Pick one system size and equipment list, and ask three installers to quote it, with the cash price shown first.
2. Run the same numbers in the Florida calculator or California calculator to see a low, likely and high range for your bill.
3. Verify each installer’s license, then compare price per watt, financing terms and warranties side by side.
4. If you want installer quotes, you can request up to three. It costs nothing and you choose whether to proceed.

An estimate is not a quote, and installer prices and your own usage will differ. The point of comparing is to see those differences before you sign.