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RoofPayback
Updated Oct 15

Solar panels in Flagstaff, AZ: payback and output

A kW of south-facing panels in Flagstaff produces about 1,688 kWh a year, 4% less than Phoenix, the Arizona reference city. Summer months produce 1.2× what winter does. To cover a typical 10,500 kWh/yr home on paper you'd need roughly 6.2 kW.

Output by month in Flagstaff (kWh per kW)

Best: May · weakest: Dec.

Jan: 115 kWhJanFeb: 129 kWhFebMar: 157 kWhMarApr: 165 kWhAprMay: 175 kWhMayJun: 169 kWhJunJul: 136 kWhJulAug: 132 kWhAugSep: 135 kWhSepOct: 140 kWhOctNov: 125 kWhNovDec: 111 kWhDec

Example 7 kW system in Flagstaff

Installed cost (example)
$21,000
Production, year 1
11,817 kWh
Savings, year 1
$1,615
Payback
12.0 years
25-year net gain
$31,655

Uses the Arizona average price (15.38¢/kWh, EIA July 2026), full net metering and no incentives. Your utility's rate and export credit may differ — change them below.

Roof direction in Flagstaff

Yearly output per kW of panels at a 20° pitch, and how it compares with a south-facing roof.

Roof faceskWh per kW/yrvs. south
South1,688—
Southeast1,619−4%
Southwest1,616−4%
East1,446−14%
West1,442−15%
East-west (split)1,444−14%

Calculate your home in Flagstaff

1 · Your roof
Roof faces
Pitch

About 6.0 kW would cover 100% of your yearly use.

2 · Your usage
3 · Prices
Paying with
Advanced assumptions

Estimated payback

12.0 years

A solid case if you plan to stay in the home.

≈ $135/month off your bill in year 1

025y
Year-1 savings
$1,615
25-yr net gain
$31,655
Return (IRR)
7.7%
Net cost
$21,000

Cumulative savings minus cost

-$21k$0$32kYear 0510152025Break-even · 12.0 yrs

Production vs. use by month

11,817 kWh/yr

Jan: 806 kWhJanFeb: 902 kWhFebMar: 1,102 kWhMarApr: 1,156 kWhAprMay: 1,222 kWhMayJun: 1,184 kWhJunJul: 953 kWhJulAug: 921 kWhAugSep: 946 kWhSepOct: 977 kWhOctNov: 876 kWhNovDec: 774 kWhDec
Production Your use

Covers 40% of your use directly; 36% of the output is used on the spot.

1,317 kWh/yr earn no credit. Your credits exceed a year of grid purchases and most utilities don't pay out the excess. A smaller system pays back faster.

Which size pays off best?

Same usage and prices, only size changes. Best 25-year gain: 7 kW.

SizeCostYear-1 savingsPayback25-yr gain
3 kW$9,000$77911.7 years$13,410
4 kW$12,000$1,03911.4 years$18,713
5 kW$15,000$1,29811.2 years$24,016
6 kW$18,000$1,55811.1 years$29,319
7 kW$21,000$1,61512.0 years$31,655
8 kW$24,000$1,61513.4 years$28,661
10 kW$30,000$1,61516.1 years$22,661
12 kW$36,000$1,61518.7 years$16,661
Estimate based on NLR PVWatts and EIA data. How we calculate.

Read the full Arizona solar guide for net metering, orientation and price trends.

Other cities in Arizona

Cities with similar sunshine

Solar in Flagstaff: common questions

Are solar panels worth it in Flagstaff, AZ?

For an example 7 kW system costing $21,000 on a home using 10,500 kWh a year, payback in Flagstaff is 12.0 years with full net metering and 15.6 years if exports earn half the retail rate, at the Arizona average price of 15.38¢/kWh (EIA, July 2026).

How much electricity do solar panels produce in Flagstaff?

About 1,688 kWh per year for each kW of south-facing panels at a 20° pitch (NLR PVWatts, typical-year weather), from 111 kWh in Dec to 175 kWh in May.

What size solar system does a home in Flagstaff need?

About 6.2 kW to cover 10,500 kWh a year. Divide your own annual use by 1,688 kWh per kW for a first estimate; if exports earn less than retail, a smaller system often pays back faster.

Does roof direction matter in Flagstaff?

Yes. Per kW at a 20° pitch: south 1,688 kWh, southeast 1,619 kWh, southwest 1,616 kWh, east 1,446 kWh, west 1,442 kWh, east-west (split) 1,444 kWh a year. South-facing roofs produce the most; east or west roofs still work, with less output.

Guides for going solar in Flagstaff

Data: NLR PVWatts v8 (U.S. DOE National Laboratory of the Rockies, formerly NREL), TMY weather near Flagstaff (35.2, -111.65), 14% losses, retrieved 2026-10-11. Published 2026-10-15.