Wind Turbine Payback in Sherman County, OR
Wind turbine payback in Sherman 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 Sherman County, OR averages 4.8 m/s (10.7 mph). A 10 kW turbine there would make about 11,212 kWh a year, worth $1,733 at OR's 15.46¢/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 Sherman County
A home turbine is not worth buying for savings in Sherman County unless your spot is far windier than the county average, 7.8 m/s at the hub against 4.8 m/s here. Per kW, solar panels would make about 1,229 kWh a year here against the turbine's 1,121, so get a solar quote first.
What would have to change
- Power would have to cost 45¢/kWh, 2.9 times what OR pays now.
- Or the average wind at the hub would have to be 7.8 m/s instead of 4.8. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of OR
Sherman County is the 1,563rd windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in OR is Gilliam County at 5.48 m/s, payback 41 years.
Month by month in Sherman County
December is the strongest month here, at 5.11 m/s and about 1,130 kWh. September is the weakest, 4.25 m/s and 650 kWh, so the best month makes 1.7 times the worst. November to March brings in 47% of the year's output in Sherman County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.02 m/s | 1,079 kWh | $167 |
| February | 4.93 m/s | 924 kWh | $143 |
| March | 5.00 m/s | 1,064 kWh | $164 |
| April | 4.87 m/s | 956 kWh | $148 |
| May | 4.71 m/s | 901 kWh | $139 |
| June | 4.91 m/s | 980 kWh | $152 |
| July | 4.75 m/s | 925 kWh | $143 |
| August | 4.47 m/s | 780 kWh | $121 |
| September | 4.25 m/s | 650 kWh | $100 |
| October | 4.55 m/s | 821 kWh | $127 |
| November | 5.02 m/s | 1,039 kWh | $161 |
| December | 5.11 m/s | 1,130 kWh | $175 |
What a taller tower would buy
Measured at 10 m the wind in Sherman County averages 3.72 m/s; at 50 m it is 5.41 m/s. That gives a shear exponent of 0.233, typical of ordinary open country. Going from 20 m to 50 m takes output from 8,574 to 15,390 kWh a year, 79% 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 | 4.37 m/s | 8,574 kWh | 75 years |
| 30 m | 4.8 m/s | 11,231 kWh | 58 years |
| 40 m | 5.14 m/s | 13,462 kWh | 48 years |
| 50 m | 5.41 m/s | 15,390 kWh | 42 years |
Counties around Sherman County
3 of the 6 closest counties are windier at turbine height; the windiest, Gilliam County, averages 5.48 m/s.
- Gilliam County, OR: 5.48 m/s, 15,893 kWh, payback 41 years (20 mi)
- Wasco County, OR: 3.62 m/s, 4,820 kWh, payback over 100 years (29 mi)
- Klickitat County, WA: 4.88 m/s, 11,734 kWh, payback 59 years (33 mi)
- Hood River County, OR: 3.14 m/s, 3,034 kWh, payback over 100 years (48 mi)
- Morrow County, OR: 5.25 m/s, 14,256 kWh, payback 45 years (52 mi)
- Wheeler County, OR: 4.53 m/s, 9,519 kWh, payback 68 years (56 mi)
Sun versus wind in Sherman County
Sherman County gets 4.21 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,229 kWh a year; one kW of the turbine above makes 1,121. Kilowatt for kilowatt, panels make 1.1 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.