Scenario: a 3,500 sq ft home. Assumes 3%/yr rate increases, 0.5%/yr panel degradation and no federal tax credit (the 30% §25D credit ended for systems installed after Dec 31, 2025). How we calculate
Data approachEIA rates · NREL sun hours · 2026 federal policy · methodology
Using floor area as a rough proxy (about 0.45 kWh per sq ft per month), a 3,500 square foot home in Arizona would use about 1,573 kWh per month — about $243/month at Arizona’s average residential rate of 15.44¢/kWh (EIA, Jan–Jul 2026 year-to-date). Real usage varies widely with climate, heating fuel and household size, so size your system from your actual kWh on your utility bills. With 6.5 peak sun hours per day, offsetting that usage takes about a 9.7 kW solar system — roughly 25 panels at 400W — costing about $29,100 installed. With no federal tax credit for 2026 installs and Arizona’s net billing / reduced export credit, simple payback is about 14.3 years, with an estimated $40,400 net over 25 years.
How Many Solar Panels for a 3,500 sq ft House in Arizona?
Arizona electricity rates and sun hours change panel count versus the US average:
System size (kW) = Annual kWh ÷ (Peak sun hours × 365 × 0.82)
For 3,500 sq ft in Arizona:
Estimated monthly usage: ~1,573 kWh
Peak sun hours: 6.5 h/day
System size:9.7 kW (~25 × 400W panels)
Metric
Arizona
US average
Rate
15.44¢/kWh
18.19¢/kWh
Sun hours
6.5 h/day
4.5 h/day
System size
9.7 kW
14.0 kW
Panels (400W)
25
35
Arizona requires a smaller system than the national average for the same square footage. Use our solar system size calculator with your actual utility bills for a precise ZIP-level result.
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💰 System Cost
What Does Solar Cost for a 3,500 sq ft Home in Arizona in 2026?
At about $3.00/W installed (a blended 2026 US price; marketplace quotes often run lower), a 9.7 kW system in Arizona costs about $29,100.
The 30% federal Residential Clean Energy Credit (IRC §25D) ended for systems installed after December 31, 2025, so a solar system you buy and install in 2026 gets no federal tax credit. Leases and PPAs are different: the installer that owns the system can still claim the commercial §48E credit for systems placed in service by the end of 2027 and may pass part of that value on through a lower monthly price.
📈 Payback Period
How Long Is Solar Payback on a 3,500 sq ft Home in Arizona?
Arizona replaced retail net metering in 2017 with a Renewable Credit Rate Rider that pays well below retail for exports. We assume solar offsets about 70% of this home’s ~$243/month bill — roughly $2,040/year — for a simple payback of about 14.3 years.
Over 25 years, with 3% annual rate increases and 0.5%/year panel degradation, cumulative savings minus the installed cost come to about $40,400. Shifting usage (EV charging, laundry, pool pumps) into daylight hours raises the value of each kWh you produce.
Solar vs utility company · 25-year comparison
25-year totals for a 3,500 sq ft home: 3%/yr rate increases, 0.5%/yr degradation, no federal credit. Methodology
State and local incentives: Arizona’s Residential Solar Energy Credit covers 25% of system cost up to $1,000, and solar equipment is exempt from state sales tax and from property-tax assessments.
Net metering: Arizona replaced retail net metering in 2017 with a Renewable Credit Rate Rider that pays well below retail for exports.
At Arizona's average rate of 15.44¢/kWh and 6.5 peak sun hours, a 3,500 sq ft home (~1,573 kWh/month) typically needs a 9.7 kW system — about 25 panels at 400W. See the [national 3,500 sq ft guide](/guides/how-many-solar-panels-3500-sq-ft-house/) for methodology.
A 9.7 kW system in Arizona costs roughly $29,100 installed. The 30% federal tax credit (25D) ended for systems installed after December 31, 2025, so there is no federal credit for a system you buy in 2026. Arizona's Residential Solar Energy Credit covers 25% of system cost up to $1,000, and solar equipment is exempt from state sales tax and from property-tax assessments.
At $29,100 installed and ~$2,040/year in bill savings, simple payback in Arizona is about 14.3 years. Arizona replaced retail net metering in 2017 with a Renewable Credit Rate Rider that pays well below retail for exports.
With about 14.3-year payback and ~$40,400 estimated 25-year net savings, it is a marginal case in 2026. Equivalent monthly bill: **~$243** — compare the [$300/month bill guide](/guides/solar-panels-300-month-electric-bill/) for bill-based sizing.
The US average needs a 14.0 kW system at 16.3-year payback. Arizona needs 9.7 kW with 14.3-year payback at 15.44¢/kWh and 6.5 sun hours.
$300/month electric bill by state
System size and payback vary by electricity rate and sun hours — see your state.
15.44¢/kWh — Arizona average residential price. Source: EIA Electric Power Monthly, Table 5.6.B (year-to-date through July 2026), residential average retail price (July 2026) (EIA)
Solar production
6.5 peak sun hours/day × 0.82 system derate. Approximate state-average daily solar resource (peak sun hours) based on NREL solar resource data (NSRDB); not location-specific — use NREL PVWatts for an address-level estimate. (NREL PVWatts)
Installed price
$3.00 per watt before incentives. Blended 2026 US residential installed price used by this site; EnergySage marketplace reported about $2.60/W (mid-2026); full-market medians are higher.
Federal tax credit
$0 for homeowner-owned systems installed in 2026 — the 30% §25D credit ended Dec 31, 2025 (IRS)
Net metering
Net billing / reduced export credit — solar assumed to offset 70% of the bill. Arizona replaced retail net metering in 2017 with a Renewable Credit Rate Rider that pays well below retail for exports.
Square footage
Used only as a rough usage proxy: 3,500 sq ft × 0.4495 kWh/sq ft/month. EIA: average US residential customer used about 899 kWh/month (2022). Site assumption: that usage corresponds to a ~2,000 sq ft home (0.45 kWh per sq ft per month). Square footage is only a rough proxy — size from your actual kWh.
Estimates only — not tax, legal or financial advice. Get at least three installer quotes and confirm incentives with your utility and a tax professional.