Wind Turbine Payback in Skamania County, WA
Wind turbine payback in Skamania 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 Skamania County, WA averages 3.12 m/s (7 mph). A 10 kW turbine there would make about 2,970 kWh a year, worth $428 at WA's 14.42¢/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 Skamania County
A home turbine is not worth buying for savings in Skamania County unless your spot is far windier than the county average, 8.1 m/s at the hub against 3.12 m/s here. Per kW, solar panels would make about 1,186 kWh a year here against the turbine's 297, so get a solar quote first.
What would have to change
- Power would have to cost 168¢/kWh, 11.7 times what WA pays now.
- Or the average wind at the hub would have to be 8.1 m/s instead of 3.12. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of WA
Skamania County is the 2,974th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in WA is Columbia County at 5.18 m/s, payback 50 years.
Month by month in Skamania County
January is the strongest month here, at 3.67 m/s and about 426 kWh. August is the weakest, 2.67 m/s and 147 kWh, so the best month makes 2.9 times the worst. November to March brings in 57% of the year's output in Skamania County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.67 m/s | 426 kWh | $61 |
| February | 3.43 m/s | 310 kWh | $45 |
| March | 3.25 m/s | 290 kWh | $42 |
| April | 3.04 m/s | 224 kWh | $32 |
| May | 2.83 m/s | 182 kWh | $26 |
| June | 2.89 m/s | 188 kWh | $27 |
| July | 2.71 m/s | 155 kWh | $22 |
| August | 2.67 m/s | 147 kWh | $21 |
| September | 2.84 m/s | 177 kWh | $26 |
| October | 3.10 m/s | 246 kWh | $35 |
| November | 3.48 m/s | 348 kWh | $50 |
| December | 3.58 m/s | 397 kWh | $57 |
What a taller tower would buy
Measured at 10 m the wind in Skamania County averages 2.06 m/s; at 50 m it is 3.79 m/s. That gives a shear exponent of 0.379, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 1,745 to 5,568 kWh a year, 219% 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 | 2.68 m/s | 1,745 kWh | over 100 years |
| 30 m | 3.12 m/s | 2,979 kWh | over 100 years |
| 40 m | 3.48 m/s | 4,260 kWh | over 100 years |
| 50 m | 3.79 m/s | 5,568 kWh | over 100 years |
Counties around Skamania County
2 of the 6 closest counties are windier at turbine height; the windiest, Multnomah County, averages 3.39 m/s.
- Clark County, WA: 2.96 m/s, 2,484 kWh, payback over 100 years (31 mi)
- Cowlitz County, WA: 2.96 m/s, 2,484 kWh, payback over 100 years (37 mi)
- Hood River County, OR: 3.14 m/s, 3,034 kWh, payback over 100 years (38 mi)
- Multnomah County, OR: 3.39 m/s, 3,905 kWh, payback over 100 years (40 mi)
- Lewis County, WA: 2.94 m/s, 2,427 kWh, payback over 100 years (43 mi)
- Columbia County, OR: 3 m/s, 2,601 kWh, payback over 100 years (54 mi)
Sun versus wind in Skamania County
Skamania County gets 4.06 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,186 kWh a year; one kW of the turbine above makes 297. Kilowatt for kilowatt, panels make 4.0 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.