Wind Turbine Payback in Adams County, ID
Wind turbine payback in Adams 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 Adams County, ID averages 2.96 m/s (6.6 mph). A 10 kW turbine there would make about 2,484 kWh a year, worth $323 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 Adams County
A home turbine is not worth buying for savings in Adams County unless your spot is far windier than the county average, 8.7 m/s at the hub against 2.96 m/s here. Per kW, solar panels would make about 1,279 kWh a year here against the turbine's 248, so get a solar quote first.
What would have to change
- Power would have to cost 201¢/kWh, 15.5 times what ID pays now.
- Or the average wind at the hub would have to be 8.7 m/s instead of 2.96. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of ID
Adams County is the 3,076th 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 Adams County
December is the strongest month here, at 3.35 m/s and about 318 kWh. June is the weakest, 2.60 m/s and 128 kWh, so the best month makes 2.5 times the worst. November to March brings in 55% of the year's output in Adams County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.26 m/s | 293 kWh | $38 |
| February | 3.14 m/s | 232 kWh | $30 |
| March | 3.17 m/s | 266 kWh | $35 |
| April | 3.00 m/s | 214 kWh | $28 |
| May | 2.71 m/s | 154 kWh | $20 |
| June | 2.60 m/s | 128 kWh | $17 |
| July | 2.65 m/s | 142 kWh | $18 |
| August | 2.70 m/s | 153 kWh | $20 |
| September | 2.72 m/s | 151 kWh | $20 |
| October | 2.97 m/s | 213 kWh | $28 |
| November | 3.28 m/s | 288 kWh | $37 |
| December | 3.35 m/s | 318 kWh | $41 |
What a taller tower would buy
Measured at 10 m the wind in Adams County averages 2.04 m/s; at 50 m it is 3.52 m/s. That gives a shear exponent of 0.339, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 1,521 to 4,408 kWh a year, 190% 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 | 2.58 m/s | 1,521 kWh | over 100 years |
| 30 m | 2.96 m/s | 2,485 kWh | over 100 years |
| 40 m | 3.26 m/s | 3,449 kWh | over 100 years |
| 50 m | 3.52 m/s | 4,408 kWh | over 100 years |
Counties around Adams County
5 of the 6 closest counties are windier at turbine height; the windiest, Payette County, averages 3.86 m/s.
- Washington County, ID: 3.6 m/s, 4,736 kWh, payback over 100 years (34 mi)
- Valley County, ID: 2.82 m/s, 2,099 kWh, payback over 100 years (41 mi)
- Gem County, ID: 3.76 m/s, 5,432 kWh, payback over 100 years (56 mi)
- Wallowa County, OR: 3.38 m/s, 3,868 kWh, payback over 100 years (61 mi)
- Baker County, OR: 3.78 m/s, 5,523 kWh, payback over 100 years (62 mi)
- Payette County, ID: 3.86 m/s, 5,894 kWh, payback over 100 years (62 mi)
Sun versus wind in Adams County
Adams County gets 4.38 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,279 kWh a year; one kW of the turbine above makes 248. Kilowatt for kilowatt, panels make 5.2 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.