Wind Turbine Payback in Clark County, ID
Wind turbine payback in Clark 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 Clark County, ID averages 3.94 m/s (8.8 mph). A 10 kW turbine there would make about 6,280 kWh a year, worth $818 at ID's 13.02¢/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 Clark County
A home turbine is not worth buying for savings in Clark County unless your spot is far windier than the county average, 8.7 m/s at the hub against 3.94 m/s here. Per kW, solar panels would make about 1,270 kWh a year here against the turbine's 628, so get a solar quote first.
What would have to change
- Power would have to cost 80¢/kWh, 6.1 times what ID pays now.
- Or the average wind at the hub would have to be 8.7 m/s instead of 3.94. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of ID
Clark County is the 2,096th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in ID is Owyhee County at 5.38 m/s, payback 51 years.
Month by month in Clark County
April is the strongest month here, at 4.40 m/s and about 718 kWh. August is the weakest, 3.59 m/s and 398 kWh, so the best month makes 1.8 times the worst. November to March brings in 44% of the year's output in Clark County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.83 m/s | 487 kWh | $63 |
| February | 4.11 m/s | 547 kWh | $71 |
| March | 4.34 m/s | 712 kWh | $93 |
| April | 4.40 m/s | 718 kWh | $93 |
| May | 3.95 m/s | 537 kWh | $70 |
| June | 3.87 m/s | 489 kWh | $64 |
| July | 3.62 m/s | 411 kWh | $54 |
| August | 3.59 m/s | 398 kWh | $52 |
| September | 3.69 m/s | 423 kWh | $55 |
| October | 3.96 m/s | 541 kWh | $70 |
| November | 3.95 m/s | 520 kWh | $68 |
| December | 3.97 m/s | 545 kWh | $71 |
What a taller tower would buy
Measured at 10 m the wind in Clark County averages 2.99 m/s; at 50 m it is 4.48 m/s. That gives a shear exponent of 0.251, typical of ordinary open country. Going from 20 m to 50 m takes output from 4,569 to 9,219 kWh a year, 102% 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 | 3.56 m/s | 4,569 kWh | over 100 years |
| 30 m | 3.94 m/s | 6,284 kWh | over 100 years |
| 40 m | 4.24 m/s | 7,820 kWh | 98 years |
| 50 m | 4.48 m/s | 9,219 kWh | 83 years |
Counties around Clark County
5 of the 6 closest counties are windier at turbine height; the windiest, Madison County, averages 4.39 m/s.
- Jefferson County, ID: 3.91 m/s, 6,134 kWh, payback over 100 years (34 mi)
- Fremont County, ID: 4.12 m/s, 7,195 kWh, payback over 100 years (43 mi)
- Madison County, ID: 4.39 m/s, 8,690 kWh, payback 88 years (49 mi)
- Butte County, ID: 4.32 m/s, 8,289 kWh, payback 93 years (58 mi)
- Beaverhead County, MT: 3.95 m/s, 6,329 kWh, payback over 100 years (64 mi)
- Teton County, ID: 4.12 m/s, 7,195 kWh, payback over 100 years (68 mi)
Sun versus wind in Clark County
Clark County gets 4.35 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,270 kWh a year; one kW of the turbine above makes 628. Kilowatt for kilowatt, panels make 2.0 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.