Wind Turbine Payback in Gilliam County, OR
Wind turbine payback in Gilliam 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 Gilliam County, OR averages 5.48 m/s (12.3 mph). A 10 kW turbine there would make about 15,893 kWh a year, worth $2,457 at OR's 15.46¢/kWh. Against an installed cost of about $100,000, that is a payback of 41 years, and the turbine is built to last about 20.
What to do in Gilliam County
A home turbine is not worth buying for savings in Gilliam County unless your spot is far windier than the county average, 7.8 m/s at the hub against 5.48 m/s here. Per kW, solar panels would make about 1,229 kWh a year here against the turbine's 1,589, so get a solar quote first.
What would have to change
- Power would have to cost 31¢/kWh, 2.0 times what OR pays now.
- Or the average wind at the hub would have to be 7.8 m/s instead of 5.48. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of OR
Gilliam County is the 1,234th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. It is the windiest county in OR.
Month by month in Gilliam County
December is the strongest month here, at 6.02 m/s and about 1,687 kWh. September is the weakest, 4.80 m/s and 919 kWh, so the best month makes 1.8 times the worst. November to March brings in 49% of the year's output in Gilliam County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.96 m/s | 1,647 kWh | $255 |
| February | 5.64 m/s | 1,306 kWh | $202 |
| March | 5.79 m/s | 1,541 kWh | $238 |
| April | 5.47 m/s | 1,298 kWh | $201 |
| May | 5.18 m/s | 1,169 kWh | $181 |
| June | 5.38 m/s | 1,245 kWh | $192 |
| July | 5.22 m/s | 1,190 kWh | $184 |
| August | 5.00 m/s | 1,065 kWh | $165 |
| September | 4.80 m/s | 919 kWh | $142 |
| October | 5.29 m/s | 1,233 kWh | $191 |
| November | 5.97 m/s | 1,599 kWh | $247 |
| December | 6.02 m/s | 1,687 kWh | $261 |
What a taller tower would buy
Measured at 10 m the wind in Gilliam County averages 4.31 m/s; at 50 m it is 6.12 m/s. That gives a shear exponent of 0.218, typical of ordinary open country. Going from 20 m to 50 m takes output from 12,615 to 20,594 kWh a year, 63% 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 | 5.01 m/s | 12,615 kWh | 51 years |
| 30 m | 5.48 m/s | 15,857 kWh | 41 years |
| 40 m | 5.83 m/s | 18,443 kWh | 35 years |
| 50 m | 6.12 m/s | 20,594 kWh | 31 years |
Counties around Gilliam County
None of the 6 closest counties is windier than Gilliam County.
- Sherman County, OR: 4.8 m/s, 11,212 kWh, payback 58 years (20 mi)
- Morrow County, OR: 5.25 m/s, 14,256 kWh, payback 45 years (33 mi)
- Klickitat County, WA: 4.88 m/s, 11,734 kWh, payback 59 years (42 mi)
- Wasco County, OR: 3.62 m/s, 4,820 kWh, payback over 100 years (46 mi)
- Wheeler County, OR: 4.53 m/s, 9,519 kWh, payback 68 years (46 mi)
- Jefferson County, OR: 3.93 m/s, 6,231 kWh, payback over 100 years (67 mi)
Sun versus wind in Gilliam County
Gilliam 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 1,589. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.3 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.