Wind Turbine Payback in Iron County, MO
Wind turbine payback in Iron 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 Iron County, MO averages 3.41 m/s (7.6 mph). A 10 kW turbine there would make about 3,980 kWh a year, worth $568 at MO's 14.28¢/kWh. Against an installed cost of about $100,000, that is a payback of over 100 years, and the turbine is built to last about 20.
What to do in Iron County
A home turbine is not worth buying for savings in Iron County unless your spot is far windier than the county average, 8.2 m/s at the hub against 3.41 m/s here. Per kW, solar panels would make about 1,241 kWh a year here against the turbine's 398, so get a solar quote first.
What would have to change
- Power would have to cost 126¢/kWh, 8.8 times what MO pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 3.41. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MO
Iron County is the 2,607th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in MO is Atchison County at 6.17 m/s, payback 33 years.
Month by month in Iron County
March is the strongest month here, at 3.99 m/s and about 553 kWh. July is the weakest, 2.62 m/s and 137 kWh, so the best month makes 4.0 times the worst. November to March brings in 56% of the year's output in Iron County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.88 m/s | 507 kWh | $72 |
| February | 3.96 m/s | 490 kWh | $70 |
| March | 3.99 m/s | 553 kWh | $79 |
| April | 3.97 m/s | 529 kWh | $76 |
| May | 3.34 m/s | 316 kWh | $45 |
| June | 2.92 m/s | 195 kWh | $28 |
| July | 2.62 m/s | 137 kWh | $20 |
| August | 2.65 m/s | 143 kWh | $20 |
| September | 2.93 m/s | 197 kWh | $28 |
| October | 3.39 m/s | 333 kWh | $48 |
| November | 3.62 m/s | 397 kWh | $57 |
| December | 3.65 m/s | 419 kWh | $60 |
What a taller tower would buy
Measured at 10 m the wind in Iron County averages 2.05 m/s; at 50 m it is 4.32 m/s. That gives a shear exponent of 0.463, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 2,116 to 8,289 kWh a year, 292% 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 | 2.83 m/s | 2,116 kWh | over 100 years |
| 30 m | 3.41 m/s | 3,980 kWh | over 100 years |
| 40 m | 3.9 m/s | 6,066 kWh | over 100 years |
| 50 m | 4.32 m/s | 8,289 kWh | 85 years |
Counties around Iron County
3 of the 6 closest counties are windier at turbine height; the windiest, Ste. Genevieve County, averages 4.69 m/s.
- St. Francois County, MO: 3.59 m/s, 4,694 kWh, payback over 100 years (18 mi)
- Madison County, MO: 3.41 m/s, 3,980 kWh, payback over 100 years (22 mi)
- Reynolds County, MO: 3.39 m/s, 3,905 kWh, payback over 100 years (23 mi)
- Washington County, MO: 3.59 m/s, 4,694 kWh, payback over 100 years (24 mi)
- Ste. Genevieve County, MO: 4.69 m/s, 10,508 kWh, payback 67 years (34 mi)
- Wayne County, MO: 3.4 m/s, 3,942 kWh, payback over 100 years (38 mi)
Sun versus wind in Iron County
Iron County gets 4.25 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,241 kWh a year; one kW of the turbine above makes 398. Kilowatt for kilowatt, panels make 3.1 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.