How to Compare Two Solar Quotes

Make the two proposals comparable

A smaller monthly payment does not tell you whether two offers include the same work. Ask both installers for a written cash price and itemized scope. Compare solar-only with solar-only, or solar-plus-battery with solar-plus-battery. If the systems differ, ask each installer to explain why.

Collect the same fields

Write down panel count, panel model, total solar capacity in kW, inverter model and predicted annual production in kWh. For a battery, record usable storage in kWh, continuous output in kW and the specific backed-up circuits. kW describes power; kWh describes energy. Keep the distinction visible rather than comparing panel count alone.

Check what the price includes

Ask about permitting, utility applications, electrical upgrades, roof work, monitoring, taxes, removal and reinstallation for later roof repairs. Mark each item included, separately priced, or unresolved. Then compare equipment, workmanship and roof-related warranty documents separately. Ask who performs service and how to request it.

A fictional price comparison

Quote A offers an 8 kW solar-only system for $24,000 in cash. Quote B offers a 9 kW system for $28,800. Dividing each price by watts gives $3.00/W and $3.20/W. That calculation helps organize a solar-only comparison; it does not prove A is better. Roof complexity, included work, equipment and warranty terms still matter. Do not use this shortcut to compare a battery-inclusive quote with a solar-only quote.

Separate the installation from the loan

Request the financed price, amount financed, APR, term, fees and total scheduled payments. The CFPB’s 2024 report describes risks from loan markups and payment changes tied to expected prepayments. Use it to identify questions, not to assume every lender has the same terms. Ask for the payment schedule with and without any optional prepayment.

Ask each installer to explain its assumptions

Request the shading inputs, expected annual production, utility tariff, export-credit assumptions and remaining-bill estimate. Ask for a lower-production scenario. A savings chart should be understandable without signing anything. In the app, open Questions to ask and keep the unresolved items for your next conversation.

Questions worth asking

• Can you quote the same equipment and scope as the other installer?
• What is excluded from this price?
• What changes the loan payment later?
• Who handles a warranty claim if the installer stops operating?