Arizona Solar in 2026: Net Billing, the Sept 1 Step-Down & the Best Payback

Yes — Arizona has the best pure payback of the major states in this guide, and the case does not depend on the federal credit. An 8 kW rooftop system costs about $21,600 (2.7/W) — the cheapest of the four-state group — and pays back in roughly 10.3 years on ~$0.155/kWh residential rates and 5.2 peak sun hours, both among the best in the nation. The Arizona Residential Solar Energy Tax Credit (25% of cost up to $1,000) is the standout state offset, and the state's abundant sun plus low installed cost carry the case even under net billing. The 30% federal residential credit (Section 25D) ended December 31, 2025, but Arizona's economics never leaned on it as heavily as slower-payback markets did.

The avoided-cost export rates that Arizona Public Service (APS), Tucson Electric Power (TEP), and UniSource Energy Services (UNSE) pay for surplus exported kilowatt-hours step down on September 1, 2026. Current export credits run roughly $0.0617/kWh at APS, $0.0513/kWh at TEP, and $0.0612/kWh at UNSE — all a small fraction of the ~$0.155/kWh retail rate — and they decline further after the step-down. Self-consumed power is unaffected: every kilowatt-hour you use on-site still offsets the full retail purchase. The practical takeaway is to size for self-consumption (air conditioning, EV charging, pool pumps during peak sun) rather than maximizing exported surplus. Salt River Project (SRP) runs its own separate schedule and does not follow this step-down.

Net billing, since 2017. The Arizona Corporation Commission eliminated full-retail net metering for the investor-owned utilities — APS, TEP, and UNSE — replacing it with reduced export credits pegged to each utility's avoided cost. Current export rates run roughly 5–7 cents per kilowatt-hour (APS ~$0.0617, TEP ~$0.0513, UNSE ~$0.0612 through September 1, 2026), a small fraction of the retail rate. SRP, a large municipal outside Corporation Commission jurisdiction, runs its own separate net-billing plan. The strategic implication is the same as California's NEM 3.0: the value proposition is self-consumption, not export.

A typical 8 kW array in Arizona runs about $21,600 (2.70/W) before incentives — among the least expensive in the country, reflecting a mature, competitive installer base and low soft costs. The Arizona Residential Solar Energy Tax Credit knocks 25% of cost (up to $1,000) off via a personal income-tax credit, and the Solar Energy Device property tax exemption (ARS 42-11054) protects you from reassessment. The 30% federal residential credit (Section 25D) ended December 31, 2025; leased/PPA systems may still capture Section 48E for projects that began construction before July 4, 2026.

It is the standout state incentive and the only remaining state-level solar income tax credit in the Sun Belt: 25% of system cost, up to $1,000, claimable against Arizona personal income tax. On a typical $21,600 system, that is the full $1,000 credit. It is one reason Arizona's payback remains the best of the four-state group even without the federal residential credit. Claim it on your Arizona state tax return for the year the system is placed in service; the credit can carry forward if your liability is below the cap. There is no state sales tax exemption for solar in Arizona.

They are structurally similar — both compensate exports at an avoided-cost rate far below retail — but Arizona's overall payback is faster because of cheaper installed cost (2.70/W vs California's ~$3.80/W) and the $$1,000 state credit that California lacks. California responds to NEM 3.0 by pairing solar with battery storage to shift generation past the midday export floor; Arizona's lower rates and cheaper hardware mean storage is optional rather than structural, justified on self-consumption and resilience (monsoon outages, summer brownouts) rather than as a payback necessity.

Not for the core payback — Arizona's abundant sun and low installed cost make a grid-tied system pencil out on its own. But under net billing, a battery that shifts midday generation into the expensive late-afternoon air-conditioning peak captures more value than exporting at a few cents, especially on APS and TEP time-of-use plans. Monsoon-season outages and summer grid stress also give storage genuine resilience value. Treat a battery as a self-consumption optimizer and resilience upgrade, not as a structural requirement the way it is under California's NEM 3.0.

Arizona averages about 5.2 peak sun hours per day — among the best in the United States, trailing only a handful of desert states. The Phoenix metro and the low desert routinely exceed 5.5, while Tucson and the southern basin land near the state average. A south-facing 8 kW array tilted near latitude (~33°) typically produces on the order of 11,700 kWh per year. Because net billing compensates exports at only a few cents per kilowatt-hour, the value-maximizing design pushes production toward the afternoon and early-evening hours when air-conditioning load peaks — a west- or southwest-facing array can capture more of that expensive peak demand even at the cost of slightly lower total generation.

If you are in APS, TEP, or UNSE territory and your project is far enough along to interconnect before September 1, 2026, doing so can lock in the current (higher) avoided-cost export rate for the grandfathering period your utility defines — confirm the exact grandfathering terms with your utility, because they vary. That said, the step-down affects only the exported portion of your production; the larger lever for most Arizona households is sizing for self-consumption so that a smaller share of generation is exported at the reduced rate at all. If your project cannot meet the date, the economics still work on self-consumption and the state credit — do not rush into a poorly sized system just to beat the deadline.

The 2026 expiration of the Section 25D residential credit sharpens the comparison. A cash purchase or low-interest loan keeps the full net-billing offset, the $$1,000 state credit (for the purchaser), the property tax exemption, and the lowest long-run cost per kilowatt-hour — typically the strongest path in Arizona given the already-low installed cost. A lease or PPA eliminates upfront cost and can still capture Section 48E (for projects that began construction before July 4, 2026), but the developer usually claims the Arizona state credit and sets your monthly payment. Because Arizona's base economics are strong, the ownership premium (the savings you keep by buying rather than leasing) is larger here than in marginal markets.

Look for an Arizona Registrar of Contractors-licensed contractor (dual AZ ROC licensing for solar), with 5+ years of in-state experience and specific familiarity with your utility — APS, TEP, SRP, and UNSE each have distinct interconnection and net-billing-plan quirks. Verify NABCEP certification, ask for recent references in your utility territory, and confirm the warranty covers both workmanship and equipment in a climate where heat degrades output over time. Walk away from any installer who still quotes a 30% federal credit on a 2026 owned-residential system — Section 25D expired December 31, 2025 — and from anyone who sizes your system to maximize export rather than self-consumption under net billing.

Arizona runs net billing (since 2017) for APS, TEP, and UNSE, with export credits at avoided cost (~$0.0617–$0.0513/kWh) that step down on September 1, 2026; SRP operates its own separate net-billing plan. The Arizona Residential Solar Energy Tax Credit (25% of cost up to $1,000) is the standout state incentive and the only remaining state-level solar income tax credit in the Sun Belt, plus a property tax exemption (ARS 42-11054). There is no sales tax exemption. The federal Section 25D residential credit expired December 31, 2025; leased/PPA systems may still access Section 48E for projects that began construction before July 4, 2026. Track current policy with our NEM policy tracker.