Wind Turbine Payback in Harper County, OK
Wind turbine payback in Harper 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 Harper County, OK averages 6.38 m/s (14.3 mph). A 10 kW turbine there would make about 22,521 kWh a year, worth $3,110 at OK's 13.81¢/kWh. Against an installed cost of about $100,000, that is a payback of 32 years, and the turbine is built to last about 20.
What to do in Harper County
A home turbine is not worth buying for savings in Harper County unless your spot is far windier than the county average, 8.4 m/s at the hub against 6.38 m/s here. Per kW, solar panels would make about 1,442 kWh a year here against the turbine's 2,252, so get a solar quote first.
What would have to change
- Power would have to cost 22¢/kWh, 1.6 times what OK pays now.
- Or the average wind at the hub would have to be 8.4 m/s instead of 6.38. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of OK
Harper County is the 359th 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 Harper County
April is the strongest month here, at 7.29 m/s and about 2,389 kWh. August is the weakest, 5.67 m/s and 1,468 kWh, so the best month makes 1.6 times the worst. November to March brings in 41% of the year's output in Harper County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.11 m/s | 1,742 kWh | $241 |
| February | 6.23 m/s | 1,645 kWh | $227 |
| March | 6.81 m/s | 2,178 kWh | $301 |
| April | 7.29 m/s | 2,389 kWh | $330 |
| May | 6.62 m/s | 2,062 kWh | $285 |
| June | 6.63 m/s | 2,000 kWh | $276 |
| July | 5.82 m/s | 1,563 kWh | $216 |
| August | 5.67 m/s | 1,468 kWh | $203 |
| September | 6.32 m/s | 1,817 kWh | $251 |
| October | 6.51 m/s | 1,995 kWh | $276 |
| November | 6.50 m/s | 1,925 kWh | $266 |
| December | 6.15 m/s | 1,765 kWh | $244 |
What a taller tower would buy
Measured at 10 m the wind in Harper County averages 4.99 m/s; at 50 m it is 7.16 m/s. That gives a shear exponent of 0.224, typical of ordinary open country. Going from 20 m to 50 m takes output from 18,458 to 28,179 kWh a year, 53% 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 | 5.83 m/s | 18,458 kWh | 39 years |
| 30 m | 6.39 m/s | 22,564 kWh | 32 years |
| 40 m | 6.81 m/s | 25,681 kWh | 28 years |
| 50 m | 7.16 m/s | 28,179 kWh | 26 years |
Counties around Harper County
5 of the 6 closest counties are windier at turbine height; the windiest, Ellis County, averages 6.76 m/s.
- Clark County, KS: 6.46 m/s, 23,112 kWh, payback 28 years (31 mi)
- Woodward County, OK: 6.69 m/s, 24,801 kWh, payback 29 years (34 mi)
- Comanche County, KS: 6.38 m/s, 22,521 kWh, payback 29 years (35 mi)
- Ellis County, OK: 6.76 m/s, 25,311 kWh, payback 29 years (40 mi)
- Woods County, OK: 6.46 m/s, 23,112 kWh, payback 31 years (45 mi)
- Beaver County, OK: 6.72 m/s, 25,020 kWh, payback 29 years (46 mi)
Sun versus wind in Harper County
Harper County gets 4.94 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,442 kWh a year; one kW of the turbine above makes 2,252. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.6 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.