How to Compare Solar Quotes, Line by Line

Two solar quotes for the same house can look like they describe two different projects. One leads with a monthly payment, another with a system size, a third with a savings chart. The trick is to pull the same lines out of each one and set them side by side.

This article walks through each line, what it tells you, and what to ask when it's missing. For where quotes fit in the whole project, see our guide to going solar, step by step.

What should you compare between solar quotes?

Compare what each quote delivers and what it costs in total. A per-watt price or a single monthly number leaves out how much power the system makes, how you pay and what's covered, so it can make a weaker quote look like the better deal. These are the lines to match up:

If a quote leaves a line blank, ask for it in writing. A company that designed the system carefully will have every one of these answers.

How do you compare system size and production?

System size, in kilowatts (kW), tells you how big the system is. Expected production, in kilowatt-hours (kWh) a year, tells you how much electricity it should make. Production is the number that saves you money, so it's the one to compare.

Add up the kilowatt-hours on your last 12 electric bills to get your yearly usage, then hold each quote's production up against it. Two systems of the same size can produce different amounts depending on where the panels sit, how much shade they get and the equipment used.

A quote that covers far less than your usage leaves a bigger utility bill behind. One that covers far more than you use means paying for power you may not need. Ask each company how it chose the size, and whether it planned for changes you mentioned, such as an electric car or a heat pump.

What equipment details should you compare?

Every quote should name the panel brand and model, the inverter brand and model, and how many of each. Be wary of "premium panels" or "equivalent equipment" without a model number, since you can't check what you can't name.

Note whether each quote uses microinverters, which sit under each panel, or a single string inverter on the wall. The choice affects how shade on one panel affects the rest and how you monitor the system. Our guide to microinverters vs. string inverters explains the trade-offs. Evergreen Solar installs Tier 1 rated panels.

How do you compare the total cost of each payment option?

Ask each company to price every way to pay on the same design. Evergreen Solar offers cash, loan, lease, power purchase agreement (PPA) and prepaid PPA, so you can see all five side by side. Then compare totals, not just first payments.

• Loan. Compare the APR, the term, the total of payments, and whether a dealer fee is built into the price. APR includes fees, so it's a fairer comparison than the interest rate. Also ask whether the payment rises later if you don't make a lump-sum paydown. Our guide to solar loan rates and dealer fees covers each of these. The federal homeowner tax credit ended for systems installed after December 31, 2025, so a loan or cash quote shouldn't count it.
• Lease or PPA. Because these systems qualify for the 30% federal credit, you get a lower rate, often a better deal than buying. Compare the starting monthly payment or price per kilowatt-hour, whether it rises each year and by how much, and the length of the contract.
• Prepaid PPA or cash. Compare the single upfront price. Evergreen Solar's prepaid PPA lets you buy out the system after 5 years.

Finally, set each monthly cost next to your current average electric bill. For most homes the solar payment is lower, and across Evergreen Solar customers, savings average about 15% on day one. With our Day One Savings Guarantee, if a solar-only quote isn't lower than your average bill, we'll contact you and offer to cancel your consultation. Our guide to solar financing compares the five options in depth.

Which incentives does each quote assume, and who applies?

State incentives can change the numbers a lot, so check that each quote counts only what you can actually get, and says who files the paperwork.

• Massachusetts: SMART 3.0 pays systems of 25 kW AC or less $0.03 per kilowatt-hour for 2026 enrollments ($0.06 for income-qualified homes), on top of net metering. The installer applies and gives you a disclosure form. See our SMART 3.0 guide.
• Connecticut: the installer applies to RRES, and you choose between Netting and Buy-All, a choice that can't change and stays with the house. With a lease or PPA, ask how Buy-All payments are split between you and the system owner. See our RRES guide.
• Rhode Island: the Renewable Energy Fund grant is for systems you own through cash or a loan, not leases or PPAs. The installer applies, and the contract must show the grant amount and what happens if it isn't approved. See our Rhode Island grant guide.

What do the warranties and sale terms say?

Warranties protect you for decades, so compare what each covers, how long it lasts, and who stands behind it. Look for the panel warranty, the inverter warranty, coverage for the installer's work, and any production guarantee. Every Evergreen Solar package includes a 25-year comprehensive solar warranty and a 25-year power production guarantee.

For any production guarantee, ask how a shortfall is measured and how you're paid for it. For each warranty, ask whether the installer handles the claim or sends you to the manufacturer.

Then check what happens if you sell. With a loan, the panels typically stay with the house, and the loan is either paid off or taken over by the buyer if the lender allows it. With a lease or PPA, selling the house typically doesn't end the payments, though some companies let new owners take the contract over if they qualify. Our guide to selling a house with solar panels explains each path.

What are the red flags in a solar quote?

• Production far above the other quotes for the same roof, with no clear explanation.
• No totals. A monthly payment without the term, the APR or the total of payments. The Consumer Financial Protection Bureau found that dealer fees are often not disclosed as a markup.
• Incentives you can't get, such as the ended homeowner tax credit on a purchase, or a grant that doesn't apply to your payment option.
• Vague equipment with no brand or model numbers.
• Claims that solar is free or that a government program pays for everything. Our guide to "free" solar panels explains these offers.

A good quote is one you can check line by line. If you'd like a second set of eyes on yours, call us at (508) 507-2908. We price every way to pay on the same design, at the same fixed price for everyone.

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