Wind Turbine Payback in Nez Perce County, ID
Wind turbine payback in Nez Perce 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 Nez Perce 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 Nez Perce County
A home turbine is not worth buying for savings in Nez Perce 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 1,168 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
Nez Perce 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 Nez Perce County
January is the strongest month here, at 4.38 m/s and about 736 kWh. August is the weakest, 3.38 m/s and 327 kWh, so the best month makes 2.3 times the worst. November to March brings in 53% of the year's output in Nez Perce County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.38 m/s | 736 kWh | $96 |
| February | 4.26 m/s | 611 kWh | $80 |
| March | 4.36 m/s | 723 kWh | $94 |
| April | 4.17 m/s | 615 kWh | $80 |
| May | 3.67 m/s | 429 kWh | $56 |
| June | 3.70 m/s | 425 kWh | $55 |
| July | 3.40 m/s | 336 kWh | $44 |
| August | 3.38 m/s | 327 kWh | $43 |
| September | 3.46 m/s | 344 kWh | $45 |
| October | 3.88 m/s | 511 kWh | $67 |
| November | 4.30 m/s | 671 kWh | $87 |
| December | 4.27 m/s | 681 kWh | $89 |
What a taller tower would buy
Measured at 10 m the wind in Nez Perce County averages 2.97 m/s; at 50 m it is 4.49 m/s. That gives a shear exponent of 0.257, typical of ordinary open country. Going from 20 m to 50 m takes output from 4,521 to 9,279 kWh a year, 105% 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 | 3.55 m/s | 4,521 kWh | over 100 years |
| 30 m | 3.94 m/s | 6,268 kWh | over 100 years |
| 40 m | 4.24 m/s | 7,841 kWh | 98 years |
| 50 m | 4.49 m/s | 9,279 kWh | 83 years |
Counties around Nez Perce County
3 of the 6 closest counties are windier at turbine height; the windiest, Columbia County, averages 5.18 m/s.
- Lewis County, ID: 3.33 m/s, 3,684 kWh, payback over 100 years (17 mi)
- Asotin County, WA: 3.69 m/s, 5,121 kWh, payback over 100 years (25 mi)
- Latah County, ID: 3.61 m/s, 4,778 kWh, payback over 100 years (34 mi)
- Garfield County, WA: 4.91 m/s, 11,933 kWh, payback 58 years (38 mi)
- Whitman County, WA: 4.84 m/s, 11,472 kWh, payback 61 years (54 mi)
- Columbia County, WA: 5.18 m/s, 13,768 kWh, payback 50 years (55 mi)
Sun versus wind in Nez Perce County
Nez Perce County gets 4 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,168 kWh a year; one kW of the turbine above makes 628. Kilowatt for kilowatt, panels make 1.9 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.