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How to Compare Solar Quotes: A 12-Point Homeowner Checklist
Compare solar proposals apples to apples using cash price, cost per watt, production, financing, warranties, equipment, and utility assumptions.
Quick answer
Compare at least three detailed written proposals using the same electricity usage. Focus on cash price per watt, annual production per kW, equipment, warranties, financing totals, roof work, utility assumptions, and the installer’s credentials—not the lowest monthly payment.
At a glance
What to check before you act
- Ask every installer for cash price, production, equipment, warranty, and financing terms.
- Compare the same system assumptions—not just monthly payment.
- Keep every promised rebate, export rate, and production assumption in writing.
Normalize every proposal before comparing it
Different system sizes make total prices hard to compare. Divide each cash price by system watts to calculate cash cost per watt. Then divide annual estimated production by system kilowatts to compare expected output per kW. These two calculations reveal whether one bid is simply larger or uses a much more optimistic production forecast.
The Department of Energy recommends comparing quotes and converting price to cost per watt. The FTC recommends detailed bids that identify system size, expected output, full installation cost, production guarantees, warranties, and other terms in writing.
The 12 points to put side by side
Create a simple table with one column per installer. If a salesperson will not provide a requested figure, mark it missing rather than guessing. A transparent proposal should make the following items easy to find.
- System capacity in DC kilowatts and panel count
- Panel, inverter, optimizer, and battery model numbers
- Cash price and cash cost per watt
- Amount financed, APR, dealer fees, term, and total payments
- Year-one production and production per installed kW
- Shading, orientation, degradation, and system-loss assumptions
- Utility tariff, export credits, and electricity-rate escalation
- Panel, inverter, battery, roof-penetration, and workmanship warranties
- Main-panel, roofing, trenching, and permit work included or excluded
- Installation schedule and interconnection responsibility
- Installer, electrician, and subcontractor licenses and insurance
- Cancellation, transfer, lien, and early-payoff terms
Cash price and financed price are not interchangeable
A solar loan can include dealer fees in addition to interest. A proposal may advertise a low APR or monthly payment while embedding substantial fees in the amount financed. Ask for the cash price, loan principal, payment schedule, and total of payments. Compare the full financed cost with the expected utility savings over the same period.
Leases and power purchase agreements create different obligations from ownership. Review escalators, transfer rules, buyout options, maintenance responsibility, and what happens when the roof needs work or the home is sold.
Choose the clearest defensible proposal—not automatically the cheapest
A very low quote can omit electrical or roofing work, use weaker service coverage, or depend on optimistic output. A high quote does not automatically mean better quality either. Give weight to clear answers, documented assumptions, verifiable credentials, references, and a contract that matches the sales presentation.
Take your time. The FTC warns against pressure to sign immediately or pay unusual advance fees. A legitimate installer should allow you to review the agreement and verify licenses, equipment, warranties, and financing.
Calculator walkthrough
Turn the guide into a home-specific estimate.
This preview shows the same inputs the calculator uses: electricity bill, home size, roof assumptions, local energy context, and current export-policy assumptions.
Try the full calculator →Electric bill
$200 / month
Home size
2,000 sq ft
Location
ZIP-based
Research and review
Reviewed for consumer-protection checks and full-price comparison guidance.
Reviewed by SolarSavings.energy Research Desk
Last reviewed August 14, 2026
This is educational content, not tax, legal, engineering, or financial advice. Confirm current incentives, tariffs, and contract terms with the relevant provider or qualified professional.
Frequently asked questions
How many solar quotes should I get?
Three detailed proposals is a practical minimum for comparison. More is useful when the designs or prices differ substantially.
What is solar cost per watt?
Divide the system’s cash price by its DC capacity in watts. It is a comparison metric, not a complete measure of quality or long-term value.
Should I choose the cheapest solar quote?
Not automatically. Compare scope, equipment, production assumptions, credentials, warranties, financing, and service in addition to price.
Primary sources
This guide was written for homeowners and reviewed against the following government and research resources. Programs and utility rules can change, so verify current details before making a financial decision.