Establish the roof condition before the array
Panels outlast most roof coverings. If your covering is within a few years of replacement, replace it first. The alternative is paying twice: once to remove and reinstall the array, and again in the disruption of doing roof work under a system that was not designed to come off easily.
Ask for a condition assessment rather than an age estimate. Intense sun, extreme summer heat and the temperature swing between day and night age roofing materials in ways that a simple year count does not capture, and a roof that looks fine from the ground may not be.
It is reasonable to get that assessment from someone other than the company selling you solar. A roofer has no stake in the array going up this month, and a second opinion on a decision this consequential is cheap.
If the roof does need replacing, doing both jobs in a coordinated sequence is usually cheaper and cleaner than doing them years apart. Ask both contractors to talk to each other about timing and about how the mounting will interact with the new covering.
How the array attaches, and who stands behind it
Ask how mounting penetrations are flashed and sealed, and what method the roofing manufacturer approves for your covering type. Tile, shingle and foam roofs are all common in this part of the Valley and they are not mounted the same way.
Leaks around mounting hardware are the most common physical failure in residential solar, and they usually appear a few years in rather than immediately. That timing is why the workmanship warranty matters more than the sales conversation suggests.
So ask what the workmanship warranty covers on roof penetrations specifically, for how long, and who honours it. A company that has left the market cannot support a warranty however well drafted, which is one reason an installer's durability is worth weighing alongside their price.
If your roof is still under a manufacturer or builder warranty, establish the position before work begins. A short call confirming what mounting approach preserves that warranty is far cheaper than establishing it during a claim.
Heat, output and honest production estimates
Panel efficiency falls as cell temperature rises, so the hottest afternoons are not the highest-producing ones. That is a real effect in the low desert and a production estimate should reflect it rather than being derived from laboratory ratings.
Ask what temperature assumptions sit behind your estimate and whether the model was run for your location and roof rather than a regional average. Ask to see monthly figures rather than an annual total, since the annual number hides how production and your cooling load line up.
Mounting height and airflow beneath the modules affect operating temperature too. Ask how the proposed mounting handles that, particularly on a low-slope or flush installation where heat has less opportunity to escape.
Then connect it to what the production is worth. Exported solar in Arizona is credited below the retail rate, so ask for the self-consumed share to be modelled explicitly and the remainder valued at the actual export rate you will be on.
The state credit you claim yourself, and the federal one that ended
Arizona still has a state income tax credit of its own, claimed on Arizona Form 310, Credit for Solar Energy Devices. It is calculated by multiplying the cost of a solar energy device by 25 percent, capped at $1,000, and the form provides for tracking credit carryover across multiple years.
Ask a tax advisor how the cap and the carryover apply to your situation before you rely on a figure in a quote. A credit is only worth what you can actually use against tax owed, and an installer is not the right party to advise you on that.
Arizona also exempts solar equipment from state sales tax and excludes it from property tax, so the improvement does not raise your property tax bill the way a renovation of similar cost would. Neither arrives as a cheque, which is exactly why they get left out of people's own arithmetic.
The federal position has changed and much published material has not caught up. The 30 percent Residential Clean Energy Credit under Section 25D expired for property placed in service after December 31, 2025, so a cash or loan purchase now does not receive it. Section 48E survives at 30 percent for third-party owners under leases and power purchase agreements, so such a provider may claim it and reflect part of the value in the rate offered. Ask what they claim and what actually reaches you, and confirm with a tax advisor.