Wind Turbine Payback in Johnson County, WY
Wind turbine payback in Johnson 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 Johnson County, WY averages 4.98 m/s (11.1 mph). A 10 kW turbine there would make about 12,400 kWh a year, worth $1,737 at WY's 14.01¢/kWh. Against an installed cost of about $100,000, that is a payback of 58 years, and the turbine is built to last about 20.
What to do in Johnson County
A home turbine is not worth buying for savings in Johnson County unless your spot is far windier than the county average, 8.3 m/s at the hub against 4.98 m/s here. Per kW, solar panels would make about 1,253 kWh a year here against the turbine's 1,240, so get a solar quote first.
What would have to change
- Power would have to cost 40¢/kWh, 2.9 times what WY pays now.
- Or the average wind at the hub would have to be 8.3 m/s instead of 4.98. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of WY
Johnson County is the 1,461st windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in WY is Albany County at 7.32 m/s, payback 24 years.
Month by month in Johnson County
January is the strongest month here, at 6.13 m/s and about 1,754 kWh. August is the weakest, 3.84 m/s and 494 kWh, so the best month makes 3.6 times the worst. November to March brings in 59% of the year's output in Johnson County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.13 m/s | 1,754 kWh | $246 |
| February | 5.71 m/s | 1,350 kWh | $189 |
| March | 5.53 m/s | 1,382 kWh | $194 |
| April | 5.01 m/s | 1,034 kWh | $145 |
| May | 4.46 m/s | 775 kWh | $109 |
| June | 4.27 m/s | 660 kWh | $92 |
| July | 3.84 m/s | 494 kWh | $69 |
| August | 3.84 m/s | 494 kWh | $69 |
| September | 4.41 m/s | 725 kWh | $102 |
| October | 5.05 m/s | 1,094 kWh | $153 |
| November | 5.64 m/s | 1,400 kWh | $196 |
| December | 5.87 m/s | 1,591 kWh | $223 |
What a taller tower would buy
Measured at 10 m the wind in Johnson County averages 3.62 m/s; at 50 m it is 5.78 m/s. That gives a shear exponent of 0.291, typical of ordinary open country. Going from 20 m to 50 m takes output from 8,907 to 18,079 kWh a year, 103% 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 | 4.43 m/s | 8,907 kWh | 80 years |
| 30 m | 4.98 m/s | 12,411 kWh | 58 years |
| 40 m | 5.42 m/s | 15,438 kWh | 46 years |
| 50 m | 5.78 m/s | 18,079 kWh | 40 years |
Counties around Johnson County
4 of the 6 closest counties are windier at turbine height; the windiest, Converse County, averages 6.97 m/s.
- Sheridan County, WY: 5.63 m/s, 16,980 kWh, payback 42 years (53 mi)
- Campbell County, WY: 6.03 m/s, 19,926 kWh, payback 36 years (54 mi)
- Washakie County, WY: 4.36 m/s, 8,517 kWh, payback 84 years (55 mi)
- Natrona County, WY: 6.38 m/s, 22,521 kWh, payback 32 years (74 mi)
- Big Horn County, WY: 4.34 m/s, 8,403 kWh, payback 85 years (77 mi)
- Converse County, WY: 6.97 m/s, 26,828 kWh, payback 27 years (91 mi)
Sun versus wind in Johnson County
Johnson County gets 4.29 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,253 kWh a year; one kW of the turbine above makes 1,240. Kilowatt for kilowatt, panels make 1.0 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.