How to Read a Solar Quote Before You Sign

The five numbers that actually tell you the story

A proposal can be 40 pages long or 2 pages long. Neither length is inherently better. What matters is whether the following five numbers are clear, consistent, and explained.

The five-number test

1. Step 1

   Price per watt

   Total price divided by system size in watts, expressed in dollars per watt. Ask whether the figure is before or after incentives, and use the same basis across quotes.

2. Step 2

   Estimated annual production

   In kWh for year one. Divide by system size in kW to sanity-check kWh per kW per year. Ask what software produced the estimate.

3. Step 3

   Term length

   For a loan, lease, or PPA. Short terms usually mean higher payments and lower total paid. Long terms usually mean the opposite.

4. Step 4

   Escalator

   The annual payment increase, if any. Apply to the full term to see the real cost.

5. Step 5

   Fee treatment

   Dealer fees, origination fees, and any rolled-in costs. Ask for the true cash price and the financed price side by side.

What a healthy proposal includes

• A clear system design with panel model, inverter model, and mounting approach.
• A production estimate with software name and key inputs like tilt, azimuth, and shading.
• A price breakdown showing equipment, labor, permitting, interconnection, and any adders.
• A plain-English description of the financing structure, including total paid over term.
• A statement of assumptions around utility-rate inflation and any tax-credit treatment.
• A roof and electrical assessment summary, not just a rooftop photo.

If any of those is missing, ask for it. Do not assume it lives in a spreadsheet somewhere.

What a healthy proposal never assumes for you

• Your tax liability. A proposal should never claim your federal credit as a sure thing without caveats.
• Your utility rate trajectory. Aggressive escalation assumptions make long-term savings look larger than they are.
• Your willingness to recast the loan. If the payment depends on you applying the federal credit as a principal payment, that assumption belongs on the first page, not buried in fine print.
• Your roof and panel condition. A good installer confirms both before quoting a system that depends on them.

Myth

If the installer is confident the credit will apply, that is good enough.

Reality

The installer is not your tax professional. Assumptions should be stated plainly and verified with your own CPA or tax preparer.

Line-by-line proposal checklist

Proposal review checklist

• [ ] System size in kW-DC and kW-AC

  DC size drives price-per-watt comparisons. AC size reflects inverter cap and real-world output.

• [ ] Module count and model

  You should know what is going on your roof, not just the brand name.

• [ ] Inverter model and count

  Microinverters, string inverters, and hybrid inverters behave differently. The quote should spell this out.

• [ ] Year-one production estimate in kWh

  And the software that produced it, with shading and orientation inputs.

• [ ] Price per watt, pre-incentive

  For apples-to-apples comparison between quotes.

• [ ] True cash price for the same scope

  Ask for it even if you plan to finance. It is the backbone of every other comparison.

• [ ] Total paid over financed term

  In dollars. Across the full term. Including any fees.

• [ ] Escalator percentage, if any

  And total-term impact in dollars.

• [ ] Assumed tax-credit treatment

  And what the payment looks like if the credit does not land as assumed.

• [ ] Warranty terms

  Panels, inverters, workmanship, and monitoring. With durations.

• [ ] Transfer and payoff behavior

  What happens if you sell before the term ends.

• [ ] Roof and electrical readiness notes

  Any caveats or required upgrades should be on paper, not verbal.

Red flags you can catch in five minutes

If you see any of these, slow down

• Monthly payment on page one, no total paid anywhere.
• Same-day signature pressure, especially tied to price.
• Vague or missing production software, or unrealistic kWh per kW.
• Utility-rate escalation assumptions above roughly 4 percent per year without clear sourcing.
• Dealer or origination fees not broken out anywhere.
• Financed price that does not match the cash price for the same scope with a reasonable explanation.
• No mention of what happens if the federal tax credit is not applied as assumed.

A clean next step

Read the quote twice. The first time, just understand it. The second time, test it against the five-number framework and the checklist above. If any of the core numbers is weak, ask in writing for clarification. A strong installer will welcome the questions. A weak one will push back on the diligence itself, which is the single most useful signal you can get.

Recommended tool

Walks through a specific proposal using the five-number frame so you do not have to do it alone.

Open the quote audit

Sources reviewed

Written with reference to NREL and DOE Energy Saver guidance on residential solar system sizing and production estimation, NYSERDA proposal quality expectations, and CFPB consumer guidance on financing disclosure. Always verify your proposal's specifics with the installer in writing before signing.

Keep reading

• Solar financing in NY in 2026: what changed, what still works

  Context for the financing parts of any proposal.

• Loan vs HELOC vs lease vs PPA: which one fits your home?

  Choose the financing structure before you sign the proposal.

• The seven questions before signing

  A tight triage list if you have limited time.

• The number your solar proposal does not show up front

  More detail on dealer fee framing.

FAQ

What is price per watt and why does it matter?

It is the total system price divided by DC system size in watts. It lets you compare quotes of different sizes on equal footing. Be sure both quotes are calculated the same way, before or after incentives.

How do I know if the production estimate is realistic?

Compare it to the system size (kWh per kW-DC per year) and ask for the software used. Aggressive assumptions show up as higher-than-typical annual output for your latitude and shading.

What is an escalator and when should I worry?

An escalator is an annual payment increase. Common in leases and PPAs. Even 2.9 percent compounds meaningfully over 20 plus years. Ask for the full-term dollar impact, not just the percentage.