Does Solar Make Sense For Your Home?

An interactive calculator that estimates a Tucson home's electricity use from ordinary details — square footage, whether the furnace, water heater and range run on gas or electric, whether a pool heater is gas or electric — then sizes a rooftop solar system, prices it under 2026 incentives and Tucson Electric Power export rates, and compares the payback year against how long the owner actually plans to stay, explaining what a cash, financed, or leased system does to a future home sale.

Rates and incentives current as of July 2026 · Tucson / Pima County, Arizona · Educational estimate — not a solar quote or tax advice

What this calculator asks

Every question is one a homeowner can answer from memory — no utility bill, rate schedule, or installer quote required. Annual electricity consumption is modelled from the answers rather than asked for directly, because almost nobody knows their own kilowatt-hours. Nothing is emailed, stored, or required to see the full answer.

1. Your house — square footage, roughly when it was built, how many people live there, and how cold you keep it in summer.
2. What runs on electricity — whether the air conditioning is refrigerated or evaporative, whether the furnace, water heater and kitchen range are gas or electric, whether there is a pool and if its heater burns gas or runs on electricity, and how many electric cars charge at home. Gas appliances barely register on an electric bill, so these answers move the result more than anything else: a gas pool heater adds almost nothing to the electric meter because the heat itself is therms, while an electric heat-pump heater roughly doubles the pool's draw.
3. Your roof — roughly which way it faces (with a 'not sure' option that still works), how much shade it gets, and how old the covering is.
4. How you would pay — cash, a solar loan, or a lease/PPA, plus whether to add a battery.
5. Your plans — how many more years you expect to own the home.

A homeowner who does know their average monthly bill can enter it, and the modelled estimate steps aside in favour of the real number.

Why Tucson solar math changed in 2026

Two changes push honest payback in Tucson to roughly 19 to 22 years for a cash purchase, well past the six to eight years commonly advertised. The first is federal: the One Big Beautiful Bill, signed July 4, 2025, terminated the Section 25D residential clean energy credit for systems placed in service after December 31, 2025, with no phase-down. A homeowner who buys with cash or a loan today receives nothing from the IRS. Only third-party ownership still reaches a credit, through the installer's Section 48E, which is why lease and PPA offers have grown more aggressive relative to purchase offers.

The second is local. Arizona ended retail net metering in 2016, and Tucson Electric Power now credits exported power at the Resource Comparison Proxy rate — about $0.057 per kilowatt-hour, locked for ten years from the interconnection request — against a retail rate near $0.14. A kilowatt-hour consumed the moment it is generated is worth roughly two and a half times one sent to the grid. The practical consequence surprises most homeowners: a system covering ninety percent of annual usage typically cuts the bill by only about half, because most of what it makes at midday is exported at the lower rate rather than used in the house.

What a system costs in Tucson, and how big to build

Budget roughly $3.00 per watt installed, which puts an 8 kW system near $24,000 and a 12 kW system near $34,000 before incentives. Price per watt falls as the array grows, because permitting, design, the inverter and the crew cost about the same either way — expect closer to $4.00 per watt on a very small system and under $2.90 on a large one. The spread between installers is wider than the spread between sizes: national brands typically quote $3.00 to $3.30 per watt while established local Tucson companies come in nearer $2.50 to $2.75 for comparable equipment.

That makes system size a smaller decision than most homeowners assume. Sliding the same house from a quarter of its annual usage up to a full offset moves the break-even year by about two years and the twenty-five-year result by roughly a thousand dollars. Two effects cancel: a larger array exports more of its output at the low $0.057 rate, which hurts, but it also spreads the fixed installation costs across more panels, which helps. The calculator puts size on a slider next to the twenty-five-year totals so the flatness of that trade-off is visible rather than asserted. Getting a second written quote is worth several times more than agonising over panel count.

Twenty-five years of solar versus twenty-five years of electric bills

The comparison solar proposals leave out is the one against doing nothing, which is not free — a Tucson electric bill escalating at three percent a year is itself a five-figure commitment over twenty-five years. The calculator totals every route all in: the system plus whatever utility bill remains afterward, since solar never removes the basic service charge and never offsets every kilowatt-hour.

On a typical Tucson home the ranking is consistent. Paying cash finishes several thousand dollars ahead of staying on the utility. The same system on a fifteen-year loan at current rates can finish thousands of dollars behind never having installed it at all, because the interest costs more than the electricity it saves. A twenty-year lease or PPA usually lands between the two and close to a wash, while adding the resale complications described below. The financing decision, in other words, matters more to the final number than the solar decision does.

Payback versus how long you are staying

This is the comparison the calculator leads with, and the one most solar quotes omit. A system that breaks even in year 14 is a good investment for an owner staying twenty years and a poor one for an owner selling in six — the same hardware, the same roof, opposite answers. The tool reports the break-even year, the cumulative position at the year you expect to sell, and the position at twenty-five years, so the decision rests on your timeline rather than on a generic payback figure.

What each ownership path does at closing

Owned outright (cash)

The simplest system to sell. The array conveys with the house like any other fixture, there is no UCC-1 fixture filing for escrow to clear, and an appraiser can credit it — though the amount comes from comparable sales rather than from what was spent. Arizona also exempts the added value of a solar energy device from property tax assessment under A.R.S. § 42-11054.

Financed (solar loan)

The system is owned, but most solar loans place a UCC-1 fixture filing against the property. It must be paid off, released, or subordinated at closing so the buyer's mortgage stays in first position, and the payoff comes out of the seller's proceeds. Owing more than the system adds to the sale price is the most common way solar loses money on a Tucson sale.

Leased or PPA

The hardest version to sell. The homeowner does not own the system, so appraisers typically assign it no value. The buyer must qualify for and assume the agreement — credit check, installer consent, and usually a transfer fee — or the seller buys out the remaining term from proceeds. It narrows the buyer pool, and transfer requests need to start well before going under contract.

Getting a solar loan or lease off the house when you sell

Underwriting draws one line and everything follows from it. Fannie Mae's Selling Guide B2-3-04 and Freddie Mac's Guide § 5601.4 both turn on whether the borrower owns the equipment: an owned system is a fixture that can carry appraised value, while a leased or PPA system is another company's personal property and carries none — the treatment FHA and VA apply as well. Separately, the buyer's lender must review any UCC-1 filing on the equipment and confirm the new mortgage keeps first lien position, so a fixture filing has to be released or subordinated before that loan can close. Solar is therefore an underwriting item and not merely a disclosure: it can stall a buyer's financing even when both parties are satisfied with the deal. These are the realistic paths, and the one to avoid is the sixth — neither side funds the buyout, the lender will not clear the filing, and the sale does not close.

The buyer assumes it (lease or PPA only)

The buyer applies to the lease or PPA provider and takes over the remaining term at the same payment and the same escalator. Approval is a credit decision: 680 is the score most providers ask for, with thresholds across the industry running roughly 650 to 700, plus the provider's written consent and a transfer fee. Watch out: Open the application weeks before closing — transfer departments are slow, and a denial discovered late reprices the whole deal. Providers also commonly refuse to assign a residential agreement to an LLC or trust, so an investor buyer usually has to sign personally.

You pay it off before closing (loan or lease)

You retire the loan, or exercise the lease's prepayment provision — typically the net present value of the payments left — so the system conveys free and clear. Escrow funds it from your proceeds and the UCC-1 gets released. Watch out: The cleanest outcome and the most expensive one. Get the payoff or buyout figure in writing before you set a list price, not once you are in escrow: on a 20-year agreement it is routinely five figures, and it comes straight off your net-to-seller.

You credit the buyer instead (loan or lease)

The contract stays where it is and you give the buyer a closing credit near the buyout amount, leaving them to decide whether to retire it or keep making the payment. Often the fastest way past an inspection-period objection. Watch out: Seller credits are capped by the buyer's loan program, and most programs will not let a credit exceed actual closing costs. Clear the number with the buyer's lender before you agree to it, or you will be renegotiating it a second time.

A partial or split buyout (lease or PPA only)

You prepay part of the term — the next five years is a common ask, often $9,000 to $12,000 — or split the buyout with the buyer, so what the buyer inherits is smaller or shorter rather than gone. Watch out: Not every provider permits a partial prepayment, and some that do will not reduce the escalator along with it. Confirm in writing what the money actually buys before you negotiate around the number.

The lender's own transfer program (loan only)

A handful of solar lenders will move a loan to a qualified buyer rather than demand payoff. It works like a lease assumption — the buyer's credit is pulled and the lender consents — and it is the only path where a financed system does not have to be retired. Watch out: Assume it is unavailable until the servicer confirms otherwise; most solar loans are simply not assumable. Note too that the lender you signed with may no longer be the one servicing the loan, which is its own delay when you need a payoff letter on a deadline.

Three warranties, three separate companies

What a proposal sells as a single 25-year warranty is usually three documents issued by three unrelated businesses, and they fail independently of one another. Ask which legal entity signed each, and get the answer in writing before signing anything.

The company that sold it to you — Whatever the contract says — frequently marketed as 25 years

Often nothing physical. Many of the national names selling residential solar are sales and finance organizations that subcontract the actual install. What they warrant is the promise: monitoring, service coordination, and any production or savings guarantee. If they are gone: The promise goes with them. A production guarantee is an unsecured contract claim and is discharged in bankruptcy. Read your contract to find which legal entity signed it — that name, not the logo on the truck or the door hanger, is the one that has to still exist.

The installer (workmanship) — Usually 10 years, sometimes advertised as 25

Labor and everything about the job that is not the equipment: roof penetrations and flashing, racking, conduit and wiring, and leaks caused by the mounts. This is the warranty you are most likely to need — water intrusion is the common solar failure, not dead panels. If they are gone: This is the layer that dies. A workmanship warranty is a service obligation of a company that no longer exists, and bankruptcy discharges it, so whoever fixes the leak afterward bills you. In Arizona the Registrar of Contractors bond and Recovery Fund is the only backstop, and it is narrow.

The manufacturers (panels, inverter, battery, racking) — 25 years on panels, 10–25 on inverters, about 10 on racking

The hardware itself, plus a performance floor on the panels — typically at least 85% of rated output still guaranteed at year 25. This layer does not depend on who installed the system, so it is the one that survives your installer's failure. If they are gone: Even honored, a panel warranty ships a panel and leaves you to pay someone to climb up and swap it, and most manufacturers require a certified installer to file the claim at all. Manufacturers fail too: Suniva filed Chapter 11 in 2017 and SolarWorld's German parent went insolvent the same year. A warranty is an unsecured liability.

Solar companies that have gone out of business

Residential solar has consolidated hard since 2022 under high interest rates, thin margins and expensive door-to-door sales costs. These are the failures a Tucson homeowner is most likely to be holding paper from. None of it is an argument against solar; it is an argument for weighing an installer's staying power as heavily as its price per watt, and for preferring a long-established local company with a bond over the best doorstep offer.

Titan Solar Power (Arizona)

Chandler, Arizona. Ceased operations June 13, 2024 and filed Chapter 7 a week later, after growing into one of the largest residential installers in the country. Its 25-year workmanship warranty went void with the company. Tucson and Phoenix homeowners were left with half-finished installs, systems never inspected or interconnected, and no one to call about a leak. Chapter 7 means liquidation, and these cases typically report no assets available for unsecured creditors — which is what a homeowner warranty claim is.

SunPower

Chapter 11 in August 2024, ending one of the oldest and most trusted brands in American solar. Complete Solaria bought the assets that September and later adopted the SunPower name. The brand on your panels survived; the company that signed your warranty did not. A buyer of assets in bankruptcy generally does not assume the seller's warranty liabilities, so pre-bankruptcy service, monitoring, and workmanship claims were disrupted even though the logo is still in business.

Sunnova Energy

Chapter 11 in June 2025. One of the largest third-party owners of residential solar leases and PPAs in the country, with hundreds of thousands of customer agreements. Leases are revenue-producing assets, so they generally get sold to another servicer rather than cancelled — but the company you call for a transfer approval, a payoff quote, or a repair changes mid-sale, and that is precisely what a seller cannot afford to have happen inside a 30-day escrow.

Mosaic (Solar Mosaic)

One of the largest residential solar lenders in the U.S. Filed Chapter 11 in June 2025 and exited that September. A lender failure does not erase your loan. The note gets sold and the payoff contact, the UCC-1 release, and the transfer department all move — sometimes more than once. Sellers who need a payoff letter on a closing deadline are the ones who feel it.

Lumio

Chapter 11 in September 2024, after assembling a national sales footprint out of several acquired regional installers. Roll-ups make the warranty question harder, not easier: the entity that signed your contract may have been a company Lumio bought, which means tracing who — if anyone — still owes you service.

Pink Energy (formerly PowerHome Solar)

Chapter 11 in October 2022 amid attorney-general investigations in several states over its sales practices. The earliest of the big failures, and the template for the rest: tens of thousands of customers with financed systems that underperformed what they were sold, still owing the lender, with no solvent company left to hold to the promise.

Arizona's own backstop is real but narrow. Residential contractors licensed by the Arizona Registrar of Contractors post a license bond of $4,250 to $100,000 depending on the license, and either pay into the Residential Contractors' Recovery Fund or post a second $200,000 bond. The Fund can reimburse actual damages, but the gate is tight: the homeowner must file a formal ROC complaint, that complaint must result in the license being suspended or revoked, and the license bond must be pursued to a final determination first. Deadlines run from completion of the work rather than from when a defect appeared, so a problem that surfaces years later usually falls outside it. Treat the bond and the Fund as partial recovery on a recent job, not as a substitute for a warranty from a company that still exists.

Assumptions behind the estimate

Household consumption

Modelled additively from the answers: a base load for lighting, refrigeration and plug loads that scales with floor area and occupants; cooling from square footage adjusted for system type, construction era and thermostat habit; then heating, water heating, cooking, pool pumping and heating, and EV charging counted only where they actually run on electricity, since a gas furnace, gas water heater, gas range or gas pool heater contributes little more than a fan or a control board to the electric bill.

Annual production

1800 kWh per kW per year for a south-facing, unshaded Tucson array, then reduced for the roof's actual orientation and shading.

Installed cost

Modelled as $4,000 of fixed cost — permitting, design, interconnection, inspection, inverter, truck rolls — plus 2.50 dollars per watt DC, so the effective price per watt falls as the array grows, the way installers actually quote. That works out to roughly 3.55 dollars per watt on a 2.3 kW system and 2.34 on a 12 kW one, matching the Tucson market as of July 2026. Add $12,000 for a battery.

Retail and export rates

0.14 dollars per kWh retail against a 0.057 dollar per kWh TEP Resource Comparison Proxy export credit.

Federal tax credit

Zero, reflecting the Section 25D termination for systems placed in service after December 31, 2025. A lease or PPA is modelled with no homeowner credit either, since the installer owns the system and claims Section 48E itself.

Arizona tax credit

25 percent of installed cost capped at $1,000 under A.R.S. § 43-1083, claimed on Arizona Form 310, with a five-year carryforward. Not available on a leased or PPA system, which the installer owns.

Self-consumption

Modelled as a saturating curve approaching 35 percent of annual load without storage and 75 percent with a battery, so a smaller array self-consumes a larger share of what it makes.

Degradation and escalation

0.5 percent output loss per year against an assumed 3 percent annual utility rate increase, over a 25-year analysis.

Roof replacement

About $450 per kW, minimum $800, charged in the year the roof covering is likely to run out, to pull the array off for a new roof and reset it.

These are educational estimates, not a solar quote, a bid, or tax advice. Kyle Berglund is a REALTOR® serving Tucson and Pima County, not a solar contractor or a CPA. Real production depends on a site survey and real pricing depends on the installer, so get at least two written quotes and take the tax questions to a CPA. Where a REALTOR® adds value is the question solar conversations skip: what the decision does to the home when it sells.

Frequently asked questions