Wind Turbine Payback in Umatilla County, OR
Wind turbine payback in Umatilla 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 Umatilla County, OR averages 5.02 m/s (11.2 mph). A 10 kW turbine there would make about 12,670 kWh a year, worth $1,959 at OR's 15.46¢/kWh. Against an installed cost of about $100,000, that is a payback of 51 years, and the turbine is built to last about 20.
What to do in Umatilla County
A home turbine is not worth buying for savings in Umatilla County unless your spot is far windier than the county average, 7.8 m/s at the hub against 5.02 m/s here. Per kW, solar panels would make about 1,232 kWh a year here against the turbine's 1,267, so get a solar quote first.
What would have to change
- Power would have to cost 39¢/kWh, 2.6 times what OR pays now.
- Or the average wind at the hub would have to be 7.8 m/s instead of 5.02. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of OR
Umatilla County is the 1,446th 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 Umatilla County
January is the strongest month here, at 6.23 m/s and about 1,821 kWh. August is the weakest, 4.07 m/s and 590 kWh, so the best month makes 3.1 times the worst. November to March brings in 60% of the year's output in Umatilla County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.23 m/s | 1,821 kWh | $282 |
| February | 5.63 m/s | 1,301 kWh | $201 |
| March | 5.47 m/s | 1,342 kWh | $207 |
| April | 4.92 m/s | 987 kWh | $153 |
| May | 4.39 m/s | 736 kWh | $114 |
| June | 4.39 m/s | 712 kWh | $110 |
| July | 4.14 m/s | 618 kWh | $96 |
| August | 4.07 m/s | 590 kWh | $91 |
| September | 4.14 m/s | 602 kWh | $93 |
| October | 4.87 m/s | 990 kWh | $153 |
| November | 5.90 m/s | 1,561 kWh | $241 |
| December | 6.14 m/s | 1,760 kWh | $272 |
What a taller tower would buy
Measured at 10 m the wind in Umatilla County averages 3.94 m/s; at 50 m it is 5.62 m/s. That gives a shear exponent of 0.221, typical of ordinary open country. Going from 20 m to 50 m takes output from 9,884 to 16,907 kWh a year, 71% 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 | 4.59 m/s | 9,884 kWh | 65 years |
| 30 m | 5.02 m/s | 12,670 kWh | 51 years |
| 40 m | 5.35 m/s | 14,960 kWh | 43 years |
| 50 m | 5.62 m/s | 16,907 kWh | 38 years |
Counties around Umatilla County
2 of the 6 closest counties are windier at turbine height; the windiest, Morrow County, averages 5.25 m/s.
- Union County, OR: 4.23 m/s, 7,787 kWh, payback 83 years (41 mi)
- Morrow County, OR: 5.25 m/s, 14,256 kWh, payback 45 years (44 mi)
- Walla Walla County, WA: 4.61 m/s, 10,008 kWh, payback 69 years (47 mi)
- Benton County, WA: 4.84 m/s, 11,472 kWh, payback 61 years (58 mi)
- Columbia County, WA: 5.18 m/s, 13,768 kWh, payback 50 years (63 mi)
- Franklin County, WA: 4.61 m/s, 10,008 kWh, payback 69 years (66 mi)
Sun versus wind in Umatilla County
Umatilla County gets 4.22 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,232 kWh a year; one kW of the turbine above makes 1,267. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.0 times. 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.