# How to Compare Solar Quotes in 2026: 8 Numbers to Check on Every Proposal

> Solar proposals are hard to compare because each installer presents savings differently. Put every quote on the same eight numbers: price per watt, production per kW, the rate and export credit assumed, the escalator, and the contract terms.

- URL: https://solarexaminer.com/posts/how-to-compare-solar-quotes/
- Site: Solar Examiner (https://solarexaminer.com/)
- Category: Solar Costs & Incentives
- Published: 2026-10-06
- Last verified: 2026-10-06
- Author: Tehseen Arbab

## Key takeaways

- Price per watt is the total price divided by system size in watts. It lets you compare quotes for different system sizes.
- Production per kW (first-year kWh divided by system kW) shows whether an installer's output estimate is realistic. Check it against NREL's free PVWatts calculator.
- Most of a quote's savings figure comes from three assumptions: your electric rate, how exported power is credited, and how fast rates are assumed to rise.
- The IRS says the residential clean energy credit is not available for property placed in service after December 31, 2025. A quote that subtracts 30% from a system you would own needs an explanation.



Three installers can look at the same roof and hand you three proposals that cannot be compared line by line. One leads with monthly savings, one with a 25-year total, one with a payback period. The way through is to pull the same eight numbers out of each proposal and put them side by side.

## The Eight Numbers

| # | Number | How to get it | What it tells you |
|---|---|---|---|
| 1 | Price per watt | Total price ÷ system watts | Whether the price is in line with other quotes |
| 2 | Production per kW | First-year kWh ÷ system kW | Whether the output estimate is realistic |
| 3 | Electric rate used | Read it from the savings page | Whether savings start from your real rate |
| 4 | Export credit used | Ask if it is not shown | Whether exported power is overvalued |
| 5 | Self-use share | Ask if it is not shown | How much output is valued at the higher rate |
| 6 | Rate escalator | Read it from the savings page | How much of the savings is a forecast |
| 7 | Payment escalator (lease or PPA) | Read it from the contract | How your payment grows |
| 8 | Warranty years | Equipment, workmanship, production | Who pays when something fails |

## 1. Price Per Watt

The Department of Energy's guidance is to "divide the cost of the system by the system's capacity in watts." Multiply kilowatts by 1,000 to get watts.

**Formula:** price per watt = total price ÷ (kW × 1,000)

Use the full contract price, before any incentive. Make sure each quote includes the same things: permits, interconnection fees, a main panel upgrade if needed, and any roof work. The Department of Energy notes that proposals should include roof repairs and vent relocation if they apply.

## 2. Production Per kW

Divide the first-year production estimate by the system size.

**Formula:** production per kW = first-year kWh ÷ system kW

Two quotes for the same roof should land close to each other. A much higher figure from one installer needs an explanation, such as different panel placement or less shading assumed. Check it yourself with PVWatts, a free calculator from the National Renewable Energy Laboratory that "estimates the energy production of grid-connected photovoltaic (PV) energy systems" from your address and roof details.

## 3 to 5. The Savings Assumptions

A savings estimate is built from this:

**First-year savings = (kWh used in the home × your retail rate) + (kWh exported × export credit)**

Three inputs decide the result.

- **Your rate.** It should be the per-kWh energy rate from your bill, not a statewide average, and not your total bill divided by kWh. Fixed monthly charges stay on your bill with solar. The Federal Trade Commission's consumer guide makes the same point: you will still pay fixed utility fees.
- **The export credit.** Under net billing, exported power earns less than the retail rate, in some territories 3 to 6 cents per kWh. Our comparison of [export credit rates by utility](/posts/solar-export-credit-rates-by-utility-2026/) lists published 2026 figures.
- **The self-use share.** If your utility pays a low export credit, the share of solar you use as it is produced drives the savings. If the proposal values every kWh at the retail rate and your utility uses net billing, the savings figure is too high.

## 6. The Rate Escalator

Long-term savings totals assume your utility's rates rise every year. The assumed percentage is usually in small print. A higher escalator produces a bigger 25-year number without changing anything about the system.

Ask each installer to rerun the estimate at the same escalator, or at zero. Compare first-year savings across quotes, since that figure depends least on forecasts.

## 7. Lease and PPA Terms

The Federal Trade Commission describes the three ways to go solar. If you buy, you own the equipment and handle maintenance. With a lease, a company installs and maintains the system and you pay a monthly amount. With a power purchase agreement (PPA), you buy the power the system generates at a rate the company sets. The FTC notes lease and PPA contracts typically last 20 years and that payments may increase over time.

For a lease or PPA, compare:

- The starting monthly payment or per-kWh price.
- The annual escalator, and what the payment becomes in year 20.
- Who receives any tax credits, incentives and renewable energy certificates.
- What happens if you sell the house.
- Early termination fees and end-of-term options.

**Formula:** payment in year N = starting payment × (1 + escalator)^(N − 1)

## 8. Warranties and the Installer

Ask for the length of the equipment warranty, the workmanship warranty and any production guarantee, and who honors each one.

On the installer, the Department of Energy suggests:

- Certification from the North American Board of Certified Energy Practitioners (NABCEP).
- Confirmation that the installer is licensed, bonded and insured in your area.
- At least three years of experience.
- Whether subcontractors will do the work, and their credentials.

## A Worked Comparison

These two quotes are invented to show the method. They are not market prices.

| | Quote A | Quote B |
|---|---|---|
| System size | 7.2 kW | 8.0 kW |
| Total price | $20,160 | $21,600 |
| First-year production | 10,080 kWh | 12,400 kWh |
| **Price per watt** | $20,160 ÷ 7,200 = **$2.80** | $21,600 ÷ 8,000 = **$2.70** |
| **Production per kW** | 10,080 ÷ 7.2 = **1,400 kWh** | 12,400 ÷ 8.0 = **1,550 kWh** |
| **Price per first-year kWh** | $20,160 ÷ 10,080 = **$2.00** | $21,600 ÷ 12,400 = **$1.74** |

Quote B looks better on every line. But it claims 1,550 kWh per kW on the same roof where Quote A expects 1,400, about 11% more. If B's panels would produce at A's rate, its first-year output is 8.0 × 1,400 = 11,200 kWh and its price per first-year kWh is $21,600 ÷ 11,200 = $1.93. The gap between the two quotes shrinks from 26 cents to 7 cents.

Then ask whether you need the extra 0.8 kW. If the additional output would mostly be exported at a low credit, the larger system adds cost faster than it adds savings.

Neither quote is wrong on this evidence. The point is that one unexplained assumption changed the ranking, and you would not see it without putting both quotes on the same measures.

## The Federal Tax Credit

The IRS states that the Residential Clean Energy Credit "is not available for any property placed in service after December 31, 2025." If a 2026 proposal for a system you would own subtracts a 30% federal credit, ask the installer to identify the credit and who claims it. In a lease or PPA the company owns the system, and the FTC notes that only system owners qualify for tax credits. State and utility incentives are separate and vary. This is general information, not tax advice. Our [solar payback guide](/posts/solar-payback-period-without-federal-tax-credit/) covers the calculation without the credit.

## Sales Tactics to Walk Away From

The FTC advises avoiding any company that "pressures you for a quick decision, tells you to sign a contract without time to review, or asks you to pay in cash." It also flags PACE financing, which places a property tax lien on your home that takes priority over your mortgage. Understand that before agreeing to it.

## Questions to Send Every Installer

1. What is the total contract price, and what is excluded?
2. What first-year production do you estimate, and what shading and losses did you assume?
3. What electric rate, export credit and self-use share did you use for savings?
4. What annual rate increase did you assume? What are savings at zero?
5. What are the equipment, workmanship and production warranties?
6. Are you NABCEP certified, licensed, bonded and insured here? Who does the installation?
7. For a lease or PPA: what is the escalator, the year-20 payment and the cost to end the contract early?
8. Which incentives are included, and who claims each one?

## Limitations

This guide gives a method, not prices. We did not use market price data, and the worked example uses invented figures. Rules on export credits and incentives differ by state and utility. Confirm your own terms with your utility, and consult a qualified professional on tax questions.

## Sources

- [U.S. Department of Energy, "Decisions, Decisions: Choosing a Solar Installer" (updated May 14, 2026)](https://www.energy.gov/cmei/systems/articles/decisions-decisions-choosing-solar-installer)
- [U.S. Department of Energy, Homeowner's Guide to Going Solar (updated May 15, 2026)](https://www.energy.gov/eere/solar/homeowners-guide-going-solar)
- [Federal Trade Commission, "Solar Power for Your Home" (updated December 9, 2025)](https://consumer.ftc.gov/articles/solar-power-your-home)
- [National Renewable Energy Laboratory, PVWatts Calculator](https://pvwatts.nrel.gov/)
- [Internal Revenue Service, Residential Clean Energy Credit](https://www.irs.gov/credits-deductions/residential-clean-energy-credit)

## Frequently asked questions

### How do I compare solar quotes?

Put each quote on the same measures: price per watt, first-year production per kW, the electric rate and export credit used in the savings estimate, the assumed annual rate increase, warranties, and for leases or power purchase agreements the starting payment and yearly escalator.

### How do I calculate price per watt?

Divide the total system price by the system's capacity in watts. Multiply kilowatts by 1,000 to get watts. A 7.2 kW system priced at $20,160 costs $20,160 divided by 7,200, or $2.80 per watt.

### How many solar quotes should I get?

The Department of Energy advises researching and interviewing several installers. It does not give a number. We suggest at least three, so you have a range for both price and production estimates.

### Can I still claim the 30% federal tax credit on a 2026 quote?

Not for a system you own. The IRS states the credit is not available for property placed in service after December 31, 2025. Ask any installer who shows a federal credit to explain which credit it is and who claims it. This is general information, not tax advice.


Image credit: Photo by Van Tay Media on [Unsplash](https://unsplash.com/photos/two-people-reviewing-documents-at-meeting-table-TFFn3BYLc5s?utm_source=solarexaminer&utm_medium=referral)