Wind Turbine Payback in Coal County, OK
Wind turbine payback in Coal 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 Coal County, OK averages 5.49 m/s (12.3 mph). A 10 kW turbine there would make about 15,965 kWh a year, worth $2,205 at OK's 13.81¢/kWh. Against an installed cost of about $100,000, that is a payback of 45 years, and the turbine is built to last about 20.
What to do in Coal County
A home turbine is not worth buying for savings in Coal County unless your spot is far windier than the county average, 8.4 m/s at the hub against 5.49 m/s here. Per kW, solar panels would make about 1,349 kWh a year here against the turbine's 1,597, so get a solar quote first.
What would have to change
- Power would have to cost 31¢/kWh, 2.3 times what OK pays now.
- Or the average wind at the hub would have to be 8.4 m/s instead of 5.49. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of OK
Coal County is the 1,228th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in OK is Cimarron County at 6.82 m/s, payback 28 years.
Month by month in Coal County
April is the strongest month here, at 6.42 m/s and about 1,878 kWh. August is the weakest, 4.34 m/s and 713 kWh, so the best month makes 2.6 times the worst. November to March brings in 50% of the year's output in Coal County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.86 m/s | 1,588 kWh | $219 |
| February | 6.04 m/s | 1,534 kWh | $212 |
| March | 6.32 m/s | 1,875 kWh | $259 |
| April | 6.42 m/s | 1,878 kWh | $259 |
| May | 5.66 m/s | 1,462 kWh | $202 |
| June | 5.03 m/s | 1,048 kWh | $145 |
| July | 4.37 m/s | 726 kWh | $100 |
| August | 4.34 m/s | 713 kWh | $98 |
| September | 4.65 m/s | 841 kWh | $116 |
| October | 5.50 m/s | 1,365 kWh | $189 |
| November | 5.94 m/s | 1,585 kWh | $219 |
| December | 5.74 m/s | 1,511 kWh | $209 |
What a taller tower would buy
Measured at 10 m the wind in Coal County averages 4.13 m/s; at 50 m it is 6.26 m/s. That gives a shear exponent of 0.258, typical of ordinary open country. Going from 20 m to 50 m takes output from 12,146 to 21,632 kWh a year, 78% 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 | 4.94 m/s | 12,146 kWh | 60 years |
| 30 m | 5.49 m/s | 15,943 kWh | 45 years |
| 40 m | 5.91 m/s | 19,036 kWh | 38 years |
| 50 m | 6.26 m/s | 21,632 kWh | 34 years |
Counties around Coal County
3 of the 6 closest counties are windier at turbine height; the windiest, Pontotoc County, averages 6.07 m/s.
- Atoka County, OK: 5.49 m/s, 15,965 kWh, payback 45 years (19 mi)
- Pontotoc County, OK: 6.07 m/s, 20,223 kWh, payback 36 years (25 mi)
- Johnston County, OK: 6.07 m/s, 20,223 kWh, payback 36 years (28 mi)
- Hughes County, OK: 6 m/s, 19,704 kWh, payback 37 years (33 mi)
- Pittsburg County, OK: 5.24 m/s, 14,186 kWh, payback 51 years (39 mi)
- Bryan County, OK: 5.29 m/s, 14,538 kWh, payback 50 years (43 mi)
Sun versus wind in Coal County
Coal County gets 4.62 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,349 kWh a year; one kW of the turbine above makes 1,597. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.2 times. 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.