Solar quotes: what to compare, and what to get in writing, before you sign

The quote is the price

Most installers publish no price, so the number on the quote is the number you’ll pay, and the quote is the document to read closely. There’s no federal credit to subtract from it either: the IRS says the Residential Clean Energy Credit is not available for any property placed in service after December 31, 2025, so a 2026 installation is priced without one. The federal credit guide has the dates.

Every item below is something to get in writing. Where a state has a rule about it, that rule is in the state’s own section. We’re a referral service, so we don’t do the work or set prices, and a quote is between you and the company.

Michigan: what to compare

Total price, with financing and fees. The number that matters is the total you’ll pay over the life of the contract, including interest and any dealer fees. The Michigan Attorney General’s July 15, 2026 lawsuit against Climax Solar is about fees: the Attorney General alleges hidden dealer fees of more than $22 million, averaging more than 27 percent of the amount financed, across about $81 million in financed transactions affecting approximately 1,700 Michigan consumers. Those are allegations in a case still before the court. What a buyer can take from them is one question, asked before signing: what’s the total financed price, with every fee named?

System size in kW DC. Ask for the size in kW DC and the number of panels. The MPSC’s consumer tips say rooftop panels need about 100 sq ft of roof per kW, so ask how much of your roof the layout uses.

Cost per watt, before any incentive. Divide the price by the system size in watts yourself if the quote doesn’t print it. Published anchors exist, and each has a source and a date:

• The MPSC’s consumer tips state “As of January 2023, the average solar panel cost in Michigan is $3.77/W.” That is a state anchor, stale by its own date.
• Lansing Board of Water & Light lists about $3.00 per watt, undated.
• The Ann Arbor Solarize FAQ, also undated, gives an average of $3.13 per watt in southeast Michigan, with a range of $2.70 to $3.80.
• Berkeley Lab’s 2026 Data Update puts the national median installed price of host-owned residential PV installed in 2025 at about $3.6 per watt before incentives, about $3.0 for known cash purchases and about $4.5 for known loan-financed systems. That’s a national figure from bar labels on a chart, and it excludes third-party-owned systems. Berkeley Lab doesn’t print a Michigan median, so the three Michigan lines above are the state anchors to hold a quote against.

Those anchors can disagree with each other and with a quote, and none of them is a price for your house. If a quote’s cost per watt sits outside all of them, ask the company to explain the gap.

Equipment, by model. Panel and inverter make and model, and the warranty on each. The MPSC advises asking what warranties come with the system, and the sections of the roof the installer penetrates are worth a separate warranty line.

Production estimate, with the tool named. Ask what tool produced the annual kWh figure and what roof direction, tilt and losses it assumed. NREL’s PVWatts calculator, run for a south-facing roof at 30 degrees with 14 percent losses, gives about 1,300 to 1,324 kWh per kW a year in five Michigan metros. DTE’s own sizing convention works out to about 1,116 kWh per kW a year. Those are two different things, a tool run and a utility’s eligibility formula, and neither is a promise about your roof or a basis for a savings figure.

Who files what, under which license. Michigan’s definition of electrical wiring includes generating equipment, so ask for the electrical contractor license number and look it up. LARA’s permit form asks for that state license number, which means the permit is pulled under the contractor’s license. Ask who files the utility application and who pulls the city permit; how solar permits work in Michigan covers both.

Purchase, loan, lease or PPA. The contract type changes what you own and what you owe. Solar leases, PPAs and loans covers the questions.

Pitches to be careful with. Consumers Energy tells customers to avoid anyone who promises that you will not receive an electric bill, claims you can be independent of the grid, or offers solar with no upfront cost. EGLE says it isn’t aware of any state or federal programs providing solar installation at no cost. The MPSC advises at least three bids, plus asking whether the company is licensed and insured, how long it has been in business and for three customer referrals. To report deceptive solar marketing, the Attorney General’s office is at 517-335-7622 or MIAG@Michigan.gov.

California: what to compare

In California, the contract rules below come from the Business and Professions Code, and the Contractors State License Board (CSLB) publishes the forms.

The contractor’s license class. A contractor holding a CSLB A (General Engineering), B (General Building, within the definition of Business and Professions Code section 7057), C-10 (Electrical) or C-46 (Solar) license can install a photovoltaic system. C-4, C-36 and C-53 cover only solar heating work. A solar salesperson must generally be a registered home improvement salesperson, unless the buyer started the sale at a fixed-location retail storefront. Ask for the CSLB license number and class, and look them up.

The disclosure cover page. Section 7169 requires the Solar Energy System Disclosure Document on the front page or cover page of every solar energy contract, in boldface 16-point type. It must show the total cost and payments including financing costs, how and to whom customers may complain, and the buyer’s right to cancel. The contract and the disclosure must be written in the language principally used in the oral sales presentation or the marketing material. CSLB says the requirement doesn’t apply to a system installed as a standard feature on new construction. CSLB’s Form 13L-6 has a line reading that the total cost for the solar energy system, including financing, is a dollar amount; if your cover page doesn’t have a total, ask why.

Payment terms. A residential solar installation is home improvement under CSLB’s bulletin 20-22. A contractor can’t ask for or take a down payment of more than $1,000 or 10 percent of the contract price, whichever is less. Apart from that, no payment may exceed work performed or materials delivered, and the contract must state the price and progress payments in dollars and cents, plus an approximate start date and completion date.

Cancellation. The buyer has three business days to cancel under Business and Professions Code 7159, five for buyers 65 or older on contracts entered on or after January 1, 2021, and the contractor must return what you paid within 10 days of the notice.

Cost per watt, before any incentive. Berkeley Lab’s 2026 Data Update puts the median installed price of host-owned residential PV installed in California in 2025 at about $3.3 per watt before incentives, a bar label read from a chart. The same report shows installer medians ranging from $2.4 to $6.3 per watt by installer.

CSLB’s own advice. Its Solar Smart page tells buyers to control payments to the contractor, not to let a financial institution make loan payments to the contractor before the work is performed, to get mechanics lien releases signed, to get savings and production claims in writing and to get three bids. CSLB receives solar complaints at 800-321-CSLB (2752) and reports them each year.

The supporting form. CSLB and the CPUC publish a Solar Energy System Supporting Information form. It asks whether subcontractors will be used, whether the deal is a PPA or lease where the customer doesn’t own the system, whether the contract can transfer to a new homeowner, and the loan terms.

A one-page checklist

Whichever state you’re in, ask for a single page that states the total price including all financing, the size in kW DC, the cost per watt before incentives, the make and model of panels and inverter, who files the utility application and who pulls the permit, the warranties, the start and completion dates, and the license number. Then compare two or three of those pages side by side.