Buying solar

How to read a solar quote

The line items that matter, and the ones designed to confuse you.

Short answer: A solar quote should state system size in kW, panel and inverter make/model, and total price. Calculate price per watt by dividing total price by system size in watts (kW × 1,000) to compare quotes cleanly. Watch for dealer or financing fees embedded in the cash price, and ask for modeled first-year production (kWh) and the assumptions behind any savings estimate.

The four essentials every quote must include

Before you compare installers, confirm that each proposal lists these core details:

System size in kilowatts (kW). A 7.5 kW array is not the same as 10 kW, even if both "cover your bill."
Panel make and model. Efficiency, warranty length, and tier vary widely. Generic labels like "Tier 1 modules" tell you nothing.
Inverter make and model. String inverters, microinverters, and power optimizers each affect cost, monitoring, and shade tolerance.
Total price. Look for a single, all-in cash figure before incentives. If the quote separates "equipment," "installation," and "soft costs," add them up yourself.

If any of these four is missing or buried in fine print, ask the installer to clarify before moving forward.

Price per watt: the cleanest comparison metric

Once you know system size and total price, calculate the price per watt:

Price per watt = Total price ÷ (System size in kW × 1,000)

For example, a $20,000 quote for an 8 kW system equals $20,000 ÷ 8,000 = $2.50/W.

Price per watt normalizes quotes of different sizes, so you can compare a 6 kW proposal at $2.80/W against a 10 kW bid at $2.40/W. It also reveals whether an installer is padding the price with dealer fees or marking up financed contracts.

Tip: Most competitive cash quotes fall between $2.00/W and $3.50/W, depending on your market, roof complexity, and equipment tier. Anything above $4.00/W warrants a second opinion.

Hidden dealer and financing fees

Many installers present a low monthly payment but inflate the cash price to cover the cost of offering 0 % or low-rate financing. This markup—often called a dealer fee—can add 15–30 % to the system cost.

To uncover it, request both:

The cash price (what you would pay if you wrote a check today).
The financed price (the total if you take the installer's loan, including all interest and fees).

If the cash price is inflated to subsidize the loan program, ask the installer to remove the dealer fee. Some will offer a true cash discount; others build the fee into every quote and won't budge.

Compare the cash price per watt across installers. Even if you plan to finance, knowing the undiscounted cost helps you evaluate whether the loan terms are worth the premium.

Production estimates and savings claims

Watch for vague language like "offsets 90 % of your usage" or "saves $50,000 over 25 years" without supporting data. To validate any savings figure, request:

Modeled first-year production in kilowatt-hours (kWh). Reputable proposals cite output from simulation tools like PVWatts.
The assumptions behind the savings estimate. What electricity rate did the installer assume? What annual rate escalation? What system degradation curve?

A 7 kW system in Phoenix will produce far more kWh than the same array in Seattle. If two quotes show identical production for the same system size, one is probably a placeholder.

Cross-check the installer's production claim with an independent model. NREL's PVWatts calculator lets you input your address, tilt, azimuth, and system size to see a research-backed estimate.

Other line items to review

Beyond the four essentials, inspect these additional details:

Warranty coverage. Panel product warranties typically run 10–25 years; performance guarantees promise a minimum output (often 85–90 % at year 25). Inverter warranties range from 10 to 25 years. Confirm what the installer's workmanship warranty covers and for how long.
Permitting and interconnection. Most quotes include permit fees, but verify that the installer will handle utility interconnection paperwork.
Monitoring. String-inverter systems often provide whole-array monitoring; microinverter platforms usually show panel-level data. Clarify whether monitoring is free or subscription-based.
Roof work. If your shingles need replacement or you want a solar-ready underlayment, some installers will bundle it; others will ask you to hire a roofer first.

For a deeper dive into how we evaluate installers on these factors, see How we score solar companies.

Comparing multiple quotes side by side

Create a simple spreadsheet with columns for installer name, system size (kW), total cash price, price per watt, panel make/model, inverter type, first-year production (kWh), and warranty terms. Sorting by price per watt will quickly highlight outliers.

Keep in mind that the cheapest quote is not always the best. A $2.20/W bid using economy panels and a 10-year inverter warranty may cost you more in replacements and lost production than a $2.60/W system with premium equipment and 25-year coverage.

Use our solar savings calculator to model the financial outcome of each proposal under your actual utility rate and usage. If you live in a high-cost market like San Diego, read Is solar worth it in San Diego? for region-specific guidance.

FAQ

Common questions

What is a good price per watt for solar in 2025?+

Competitive cash quotes typically range from $2.00 to $3.50 per watt, depending on your location, roof complexity, and equipment quality. Quotes above $4.00/W often include dealer fees or financing markups and deserve scrutiny.

Should I choose the lowest-price solar quote?+

Not automatically. Compare equipment warranties, production estimates, and installer reputation. A low bid using budget panels and short inverter coverage may cost more over the system's lifetime than a moderately higher quote with premium components.

How do I know if a production estimate is accurate?+

Ask the installer for the modeled first-year production in kWh and the tool used (such as PVWatts). Cross-check the figure by running your own simulation at NREL's PVWatts website using your address, roof tilt, and system size.

What is a dealer fee in a solar quote?+

A dealer fee is a markup added to the cash price to cover the cost of offering low- or zero-interest financing. It can inflate the system cost by 15–30 %. Request both cash and financed prices to identify any hidden fees.