The 30% federal tax credit ended Dec 31, 2025

Three solar quotes with three different bottom lines and none of them are comparable.

Each installer used their own assumptions about your shade, your roof, and how your electric rate will grow. We rebuild every quote on one set of numbers, then rank them against the option missing from the quotes: leaving the money invested.

Run the free quote check on your quote →Instant. No account, no email. Every assumption is shown along with its source.We don’t sell panels, and installers never get your contact info.

For more detail and to compare quotes, get the full $29 report.

Delivered in 24 hours. Full refund within 7 days if the report doesn’t help you decide.

Free quote check

Check your quote now

Enter the numbers from your installer’s quote. You’ll see how the price compares with what other homes in your state paid, how the production estimate compares with NREL’s for your ZIP code, and whether the money would do better left invested.

What this means

A ZIP code is the five-digit number in a mailing address. It identifies the home's location, which affects the amount of sunlight the panels receive, the price of electricity, and the rebates that are available.

Electricity use (enter one)

Enter the average monthly electric bill. Monthly kWh is more precise, because the bill includes fixed charges.

What this means

Electricity use is the amount of electricity the home consumes, measured in kilowatt-hours (kWh). The monthly bill lists the cost of that electricity in dollars.

What this means

A kilowatt-hour (kWh) is a unit of electricity. A 1,000-watt microwave running for one hour uses one kWh.

What this means

The quoted price is the total amount the installer charges to install the system, before any rebates or discounts.

What this means

System size is the amount of power the panels can produce at one time in full sunlight, measured in kilowatts (kW). A larger number means a larger system.

Utility credit for exported power

This is the rate at which the utility credits electricity that the system sends to the grid. If the credit is unknown, the results are calculated at both ends of the export-credit range.

What this means

When the panels produce more electricity than the home is using, the extra electricity flows to the utility's lines. The export credit is the amount the utility pays for that electricity.

The results are calculated twice, once with full retail credit and once at the lower end of the export-credit range. The annual return, first-year savings and payback are shown for both. All other figures are based on the lower end.

The utility credits each unit of extra electricity at the same price the home pays to buy it, and unused credit carries over for the year. This rule is common in the Midwest and Northeast.

The utility credits extra electricity at less than the price the home pays to buy it. Enter the percentage if the utility publishes it.

The utility credits extra electricity at full price, but any credit left at the end of a month expires instead of carrying over to later months.

The utility pays nothing for extra electricity. Only electricity the home uses at the moment it is produced has value. Some cooperative and city-owned utilities follow this rule.

Additional details (optional)

Use these fields to improve the production comparison, the roof limit, the size-limit check, and the monthly usage estimate.

What this means

Annual production is the amount of electricity the panels are expected to produce in one year. NREL PVWatts is a free tool from a U.S. government laboratory. It is used to estimate production from local weather records.

What this means

The number of solar panels the installer plans to install on the roof.

What this means

The largest number of panels that fit on the roof, according to the installer's roof layout drawing.

What this means

The number of years the owner expects to keep living in the home.

Heating and cooling

This is used to estimate how electricity use varies from month to month.

What this means

The type of equipment that heats and cools the home. Electric heating increases electricity use in winter. Air conditioning increases it in summer.

Utility size limit

Some utilities limit system size, or the incentive on it, to a percentage of past usage.

What this means

Some utilities will not approve a system that produces much more electricity than the home has used in the past. The limit is usually a percentage of past use, such as 120%.

Assumptions (optional)

Blank fields are set to the default or looked-up value shown in the field.

Primary assumptions

Energy price escalation and the market benchmark have the largest effect on the result.

What this means

How much the price of electricity is expected to increase each year. At 2.5%, a $100 electric bill becomes approximately $102.50 the following year.

What this means

A common investment used for comparison. The comparison is whether the same money would grow more if spent on solar panels or if placed in this investment.

Roof

What this means

The compass direction the roof faces. In the United States, south-facing roofs receive the most sunlight.

What this means

The angle of the roof, measured in degrees. A flat roof is 0°. A vertical wall is 90°.

What this means

Electricity lost before it reaches the home because of shade, dirt on the panels, wiring, and equipment. A 14% loss means the home receives 86% of the electricity the panels produce.

Looked-up values

What this means

The price the home pays for each kilowatt-hour of electricity, in cents.

What this means

Money from a state, city, or utility that reduces the price of the system, such as a rebate.

What this means

The middle price per watt paid for solar by other homes in the state. Half of those homes paid more, and half paid less.

What this means

The amount of greenhouse gas that power plants in the region release to produce each unit of electricity. Electricity from solar panels replaces some of that pollution.

Investment comparison

What this means

The interest that saved money earns while it is kept in a savings account or a similarly safe place.

Modeling assumptions

What this means

The number of years of costs and savings included in the calculation.

What this means

Solar panels produce slightly less electricity each year as they age. This is the yearly reduction.

What this means

A method of valuing money received in the future at less than money received today. At a higher rate, future savings have less value.

What this means

Operations and maintenance: the yearly cost of cleaning, inspecting, and repairing the system.

What this means

The inverter is the device that converts the panels' electricity into the type the home uses. It usually wears out before the panels and is replaced once. This is the cost of that replacement.

What this means

The year in which the inverter is expected to be replaced.

What this means

The share of the panels' electricity that the home uses at the moment it is produced, without a battery to store it.

How it works

  1. 1. Check one quote free.

    Enter the numbers from your quote and see the answer right away. No email needed.

  2. 2. Get the in-depth report if you need more.

    Have more than one quote, a lease, or a loan? Order the $29 report and fill in a short form. Blanks are fine.

  3. 3. Take the numbers back to your installer.

    Within 24 hours you get your quotes ranked, the price to ask for, and the questions to ask.

What changed in 2026: The One Big Beautiful Bill ended the 30% residential solar tax credit on Dec 31, 2025.2 Buy with cash or a loan and there is no federal credit. Lease and Power Purchase Agreement (PPA) companies can still claim a commercial credit through Section 48E, with deadlines attached, and they keep it unless your contract passes some of it on to you. State incentives vary wildly and some are already out of funding. The right answer depends on where you live, how you pay, and what rate that money could earn somewhere else.

Why this site exists

I built a fifteen-tab spreadsheet to decide this for my own house. I put hours into analysis and research, and my model was wrong. You shouldn’t have to go through that process.

Two installers with four configurations of panels and a battery option on each. High efficiency or standard panels. Eleven columns across fifteen sheets, built to make a $45,000 decision.

For weeks my model told me the best option lost $98,000 compared to the S&P 500. Every solar scenario delivered negative NPV. Seven of the eight scenario sheets were subtracting the avoided electric bill instead of adding it, and I hadn’t noticed.

I fixed the error and the numbers still fought me:

A capable person, with real quotes, motivated by his own money, spending hours, produced a model that returned garbage for weeks before it worked. That’s the whole problem with solar quotes, and it’s why you need a software tool rather than a spreadsheet you built yourself.

Everything below runs on an engine built to catch all the things I missed the first time through and many more.

The fine print

Where solar contracts cost people money

Solar is a 20 to 25 year financial commitment attached to your roof, and most people only buy it once. These are the traps to watch for.

What this looks like in practice

Three different homeowners, three different messes

These are hypothetical but realistic scenarios, built from the problems this engine actually solves.

Wayne, Aurora, Illinois. Three quotes, three different approaches.

Wayne got three quotes from three companies. They used different panel brands, different system sizes, and different assumptions, so none of them were comparable. One was conservative about sunlight and showed a long road to positive ROI. Another showed lots of sun, a little shade, and a short payback. The third insisted he needed a battery to make the numbers work.

Wayne spent evenings trying to convert one quote’s metrics into another’s terms, but didn’t know whose assumptions to trust as his baseline. Every quote felt wrong, and he had no way to know which one was or why.

Here’s what the tool does with Wayne’s three quotes: rebuilds all three on one set of numbers (same production assumption, same rate escalation, same panel degradation), strips the battery out of the third quote’s price so it’s comparable to the other two, and prices the battery separately as its own investment. Then it ranks all three against a benchmark none of the installers used: leaving the money invested instead.

The report doesn’t just say “quote 2 is best.” It says: quote 2 wins on price per watt, but quote 3 maximizes your roof’s capacity. Here’s what that’s worth, and here’s the configuration to take back to quote 2’s installer to get the best deal.

Dana: a lease that looked cheaper than buying.

Dana’s lease quote showed a lower monthly payment than the loan quote for the same system. On paper, the lease won. Dana worried she was missing something, but couldn’t put her finger on what it was.

The tool takes the five numbers from the lease (upfront, monthly, escalator, term, buyout) and runs the whole structure over 25 years against purchasing the same system and against not installing at all. The escalator, which looked harmless at 2.9%, compounds into the biggest number on the page by year 15.

Marcus: the battery that was never given a chance to win.

Marcus lives in Fresno, California, and uses about 503 kWh a month, the state average.3 He had two quotes for the same 3.6 kW system at $3.25 per watt, the California median.4 One installer added a Tesla Powerwall 3 at $13,473, its typical installed price,5 and showed one savings number for the whole package. The other quoted panels only, and insisted a battery would never pay off.

The tool takes the battery out of the first quote and prices it as its own investment against his actual rate plan. PG&E puts new solar customers on its Electric Home rate (E-ELEC), where summer evenings from 4 to 9 pm cost 55¢ a kWh.6 What PG&E pays for his exports changes by the hour. It’s about 1¢ at midday in spring, and more than $1 on August evenings in his first three years.78

The battery saves him about $726 in its first year. Over its 10-year warranty, those savings are worth $5,316 in today’s dollars. That’s $8,157 less than the battery costs, so investing the $13,473 does better. The panels-only installer was right about this battery at this price. The report still gives Marcus the price that would change the answer: under $5,316, the battery beats investing. That’s less than half of what it costs installed today.

What your $29 buys

An excerpt from the report, on a house like yours

This is the report’s own math on one house in Massachusetts. The free check runs the same math on your quote, and the report runs it on every quote you’ve got.

Excerpt: a 7.5 kW quote in Cambridge, Massachusetts

Cost and production. At 29¢/kWh, a 7.5 kW system bought with cash at $3.40 per watt costs $25,500, with no federal credit. NREL’s PVWatts expects it to make about 8,625 kWh in its first year. What that’s worth depends on something the installer’s proposal leaves out: what the utility pays for the power the system sends back to the grid.

Two export-credit cases. If the utility credits exports at the full retail rate, the system takes about $2,501 off the first-year bill and pays for itself in about 9.5 years. Over 25 years it returns 10.3% a year. That’s after maintenance and a $1,650 inverter replacement in year 13. If exports earn a quarter of retail, it saves about $1,374 in the first year and takes about 17.2 years to pay back. Its return drops to 3.9%. The bar is 9.4%. That’s the S&P 500’s long-run 10.0%, less 15% tax on the gains. So it’s a yes under one tariff and a no under the other. The report tells you which one you’re on, and the one phone call that settles it.

Comparisons with investing. Bank each year’s savings at the 3.9% T-bill rate and they add up to about $126,000 by year 25 with full credit. With the lower credit, it’s about $66,000. Put the same $25,500 into 3-month T-bills on day one and it grows to about $60,000. In an S&P 500 index fund at the 1928 to 2025 average, taxed at 15% on the gains at the end, it reaches about $240,000. Nobody guarantees that return, and the index has halved twice since 2000. Massachusetts SMART incentives aren’t in these numbers, and they would make solar look better.

Inputs: 8,600 kWh/yr use, 29¢/kWh, 7.5 kW DC at $3.40/W, 1,150 kWh per kW per year, no federal credit, 25-year horizon, export credit run at 100% and at 25% of retail. Savings reinvested at the T-bill rate (FRED DGS3MO); benchmark returns from Damodaran, NYU Stern; lump sums taxed at 15% on gains. Every figure here is calculator output, pinned by a test.

What the $29 in-depth report will tell you

The modelling that took me weeks to build

  1. All your quotes on one set of numbers.

    Different panel counts, different wattages, batteries bundled into some prices and not others: quotes aren’t comparable as written. We normalize them, strip the bundling, and rebuild each at one production assumption before comparing anything.

  2. Counteroffers to take back to your installer.

    The configuration and price to take back to a specific installer: the negotiating column. In my own workbook, the most valuable columns were quotes that didn’t exist yet. You also get the highest price at which that system still beats investing, so you know when to stop negotiating.

  3. Incentives checked against their size limits.

    The incentives from your quotes, along with their constraints, and any other programs listed for your ZIP code that your quotes don’t mention. If a system is over a size cap, the report shows by how much. The report gives you the questions to ask your installers.

  4. Batteries priced as their own investment, not bundled.

    If a battery never returns your money, the report says by how much, why, and whether waiting changes the answer.

  5. Comparisons with investing the same money.

    The system’s cost, offset by bill savings invested as they occur at market rates, compared with the same amount invested in the market on day one and taxed on gains at the end. The discount-rate choice is stated clearly. It answers the most important financial question of all: “Is this purchase better than leaving the money invested?”

  6. Buy, lease and PPA comparisons on real terms.

    Give us the five numbers off the lease (upfront, monthly, escalator, term, buyout) and it models what this costs over 25 years against buying the same system, or not buying at all.

  7. Dealer fees inside your loan.

    Low-rate solar loans often carry a fee the lender adds to your balance.1 The report shows how much of your loan is fee, and prices the loan at what you’ll actually repay.

Our commitments to you: we won’t sell you panels, we don’t collect referral fees, your contact info never goes to installers, and the report says “don’t buy” when the math says “don’t buy.”

Delivered in 24 hours. Full refund within 7 days if it doesn’t help you decide.

After checkout you’ll complete a short form: address, utility, electric usage, and your quotes. Start with whatever you have. Blanks are fine if you don’t know; we have sources for your area’s averages. We’ll show you our standard assumptions and give you the chance to enter your own.

Free first, then the full math

Run the free check. Then decide if you need the rest.

Free check$29 in-depth report
Quotes1Up to 3, ranked
Price per watt and production checkYesYes
Solar against investingYesYes
Target price for your installerNoYes
Loan dealer feeNoYes
Lease and PPA, year by yearWarning onlyYes
Incentive size capsFlaggedChecked, in kWh and panels
Battery as its own investmentNoYes
TurnaroundInstantWithin 24 hours

The free check tells you how your quote compares to the average. If you’ve got more than one quote, or a lease offer, the in-depth report will help you decide.

What $29 buys

Priced against what the alternatives cost

  • Solar contracts: $25,000 or more, and you live with it for 20 to 25 years. $29 is about a tenth of a percent of that.
  • Independent energy consultants: billed by the hour, for a single-home analysis.
  • Installers’ “free analyses”: $0, and they’re part of the sales funnel installers run you through. Can you trust them?
  • DIY spreadsheets: my spreadsheet took fifteen tabs and several weeks of night and weekend work, and it almost cost me thousands of dollars on a bad decision. That story is above. Save the time and energy. Avoid the risk of mistakes.

The guarantee, in full: full refund within 7 days if the report doesn’t help you make the decision. Email us and say so. You don’t have to justify it.

Delivered in 24 hours. Full refund within 7 days.

How this works

We’re not in the solar business

We don’t sell panels or install systems, and we take no referral fees
Your contact info will not be shared with third parties. No phone calls from installers
If the math says don’t go solar, that’s what the report says
Every number in the report shows its source, with an explanation of how it was derived

Common questions

Before you order

What do I need to provide?
After checkout, a short form: your address, your utility and what you pay (bill, kWh or rate; any one will do), notes on your roof including how many panels will fit, how long you expect to stay in your house, what else you’re considering (solar, battery, heat pump, EV charger), how you’d prefer to pay for the system, and any quotes you already have. You can leave blanks to use area averages.
Will installers get my information?
No. We don’t sell or share your contact info, and no installer will call you because you used this site.
Why not just ask my installer?
You should, and the report gives you the questions to ask. But the installer picked the assumptions in the quote, and they get paid when you sign. The report checks their numbers against sources that have no stake in your decision.
Is there a free version?
Yes, and it’s a great gut check against a quote you receive. The free quote check runs our engine on one quote, giving you a verdict, price per watt against your state median, payback period, the investment comparison, and every assumption with its source. The $29 in-depth report is for when one verdict isn’t enough: multiple quotes, lease terms, and the renegotiation column.
I only have one quote. Do I need the report?
Maybe not. Start with the free check. If you get more quotes or a lease offer later, the in-depth report will compare them for you.
How is this different from a free solar calculator?
Many free calculators give you an estimate and then route you to an installer. Even the unaffiliated calculators are too simplistic to accurately model your situation. This tool runs the math installers leave out: normalizing quotes that share no common assumptions, pricing the battery as its own investment, comparing solar to an index fund. And it shows its sources. The output is a report you can use, not a sales funnel.
What if the report says solar isn’t worth it?
Then you just avoided a $25,000+ mistake. That’s the point. Confirmation is an outcome too: if the math says the quote you got is a great deal, the report proves it with your own numbers.
Do you cover batteries and heat pumps too?
Yes. If you’re considering any combination of solar, battery storage, heat pump, or EV charger, the report covers sequencing, how new equipment affects your utility’s size limit, and how to determine whether each one is worth doing right now or waiting until later. That includes the load-growth question: electrification can more than double your usage, and that changes which solar system size is best for you.
Can I see a sample before paying?
Yes. The excerpt above is the report’s own math on one house, with every input listed. And the free check runs the same math on your quote right now.
Can I get a refund?
Full refund within 7 days if the report doesn’t help you decide. Email us; you don’t have to justify it.

One of two things happens

Either the math says your quote is a good deal, and you’ll have the numbers to prove it, or it says the deal is bad, or the lease is worse than it looks, or the battery is a $10,000 mistake. Either way, you’ll know what to do and how to get the best deal for your specific situation.

Both outcomes are worth $29. Avoiding an expensive mistake is worth a lot more than that.

Delivered in 24 hours. Full refund within 7 days if it doesn’t help you decide.Or start with the free quote check →

Sources

  1. Consumer Financial Protection Bureau, Solar Financing Market: Issue Spotlight, August 2024. Sections “Hidden Markups and Fees” and “Misrepresentations and Omissions Concerning Prepayments.” Read the report (PDF)
  2. One Big Beautiful Bill Act, Public Law 119-21 (2025), section 70506, ending the residential clean energy credit (26 U.S.C. § 25D) for expenditures made after December 31, 2025. IRS summary of the change
  3. U.S. Energy Information Administration, 2024 Average Monthly Bill, Residential (Table 5A): California, 503 kWh a month. Read the table (PDF)
  4. Lawrence Berkeley National Laboratory, Tracking the Sun: California median installed price, $3.25 per watt, 7,038 systems installed in 2025. Tracking the Sun
  5. EnergySage, Tesla Powerwall 3 review, updated May 15, 2026: $13,473 typical installed cost before incentives, 13.5 kWh usable. Read the review
  6. PG&E, Electric Schedule E-ELEC (Electric Home), total bundled rates and time periods, effective June 1, 2026. PG&E requires residential Solar Billing Plan customers to take service on this schedule. Read the tariff (PDF)
  7. PG&E, Solar Billing Plan export rates: the 2026 vintage's export value for each hour of each month and calendar year, weekday and weekend, generation plus delivery. Download the export rate files (ZIP)
  8. PG&E, Electric Schedule NBT (Net Billing Tariff): the 2026 residential ACC Plus adder of 0.88¢ per kWh exported, for nine years. Read the tariff (PDF)

The excerpt lists its own sources with its inputs. The $5,187, 1.4%, and $10,238 figures come from the founder’s own workbook.