Wind Turbine Payback in Pima County, AZ
Wind turbine payback in Pima County
No. The turbine wears out before it pays for itself.
At 30 m, the height a home turbine tower usually reaches, the wind in Pima County, AZ averages 4.58 m/s (10.2 mph). A 10 kW turbine there would make about 9,824 kWh a year, worth $1,509 at AZ's 15.36¢/kWh. Against an installed cost of about $100,000, that is a payback of 66 years, and the turbine is built to last about 20.
What to do in Pima County
A home turbine is not worth buying for savings in Pima County unless your spot is far windier than the county average, 7.8 m/s at the hub against 4.58 m/s here. Per kW, solar panels would make about 1,717 kWh a year here against the turbine's 982, so get a solar quote first.
What would have to change
- Power would have to cost 51¢/kWh, 3.3 times what AZ pays now.
- Or the average wind at the hub would have to be 7.8 m/s instead of 4.58. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of AZ
Pima County is the 1,700th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in AZ is Apache County at 5.25 m/s, payback 46 years.
Month by month in Pima County
April is the strongest month here, at 5.23 m/s and about 1,162 kWh. August is the weakest, 3.65 m/s and 422 kWh, so the best month makes 2.8 times the worst. November to March brings in 43% of the year's output in Pima County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.63 m/s | 859 kWh | $132 |
| February | 4.69 m/s | 806 kWh | $124 |
| March | 4.77 m/s | 935 kWh | $144 |
| April | 5.23 m/s | 1,162 kWh | $178 |
| May | 5.14 m/s | 1,148 kWh | $176 |
| June | 5.14 m/s | 1,111 kWh | $171 |
| July | 4.06 m/s | 583 kWh | $90 |
| August | 3.65 m/s | 422 kWh | $65 |
| September | 4.10 m/s | 583 kWh | $90 |
| October | 4.34 m/s | 714 kWh | $110 |
| November | 4.57 m/s | 804 kWh | $123 |
| December | 4.68 m/s | 887 kWh | $136 |
What a taller tower would buy
Measured at 10 m the wind in Pima County averages 3.58 m/s; at 50 m it is 5.14 m/s. That gives a shear exponent of 0.225, typical of ordinary open country. Going from 20 m to 50 m takes output from 7,528 to 13,490 kWh a year, 79% more, before counting the extra cost of the taller tower. Why tower height decides it explains the shear behind these numbers.
| Hub height | Average wind | Output | Payback |
|---|---|---|---|
| 20 m | 4.18 m/s | 7,528 kWh | 87 years |
| 30 m | 4.58 m/s | 9,836 kWh | 66 years |
| 40 m | 4.89 m/s | 11,789 kWh | 55 years |
| 50 m | 5.14 m/s | 13,490 kWh | 48 years |
Counties around Pima County
2 of the 6 closest counties are windier at turbine height; the windiest, Cochise County, averages 4.69 m/s.
- Pinal County, AZ: 4.22 m/s, 7,732 kWh, payback 84 years (60 mi)
- Santa Cruz County, AZ: 4.65 m/s, 10,257 kWh, payback 64 years (69 mi)
- Maricopa County, AZ: 4.09 m/s, 7,038 kWh, payback 93 years (94 mi)
- Cochise County, AZ: 4.69 m/s, 10,508 kWh, payback 62 years (119 mi)
- Graham County, AZ: 4.09 m/s, 7,038 kWh, payback 93 years (124 mi)
- Gila County, AZ: 4.05 m/s, 6,831 kWh, payback 95 years (128 mi)
Sun versus wind in Pima County
Pima County gets 5.88 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,717 kWh a year; one kW of the turbine above makes 982. Kilowatt for kilowatt, panels make 1.7 times as much here as the turbine. Panel output assumes an 80% system performance ratio. Wind or solar runs the same comparison for every county.
How this is worked out
Wind is NASA's Power climate record, the 2001-2025 average at 10 m and 50 m for the county's centre, carried to 30 m with this county's own measured wind shear and spread into hours with a Rayleigh distribution. The turbine is a generic 10 kW, 7 m rotor machine with 10% losses. Cost is $10,000 per kW installed with no tax credit, because the federal one ended in 2025. One county-centre number cannot see your hilltop or your tree line, so treat it as the starting point for a site survey, not a substitute. The full method and its weak spots are in how the numbers are made.