Wind Turbine Payback in Stevens County, WA
Wind turbine payback in Stevens 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 Stevens County, WA averages 2.55 m/s (5.7 mph). A 10 kW turbine there would make about 1,456 kWh a year, worth $210 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 Stevens County
A home turbine is not worth buying for savings in Stevens County unless your spot is far windier than the county average, 8.1 m/s at the hub against 2.55 m/s here. Per kW, solar panels would make about 1,063 kWh a year here against the turbine's 146, so get a solar quote first.
What would have to change
- Power would have to cost 343¢/kWh, 23.8 times what WA pays now.
- Or the average wind at the hub would have to be 8.1 m/s instead of 2.55. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of WA
Stevens County is the 3,136th 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 Stevens County
March is the strongest month here, at 2.75 m/s and about 163 kWh. January is the weakest, 2.34 m/s and 88 kWh, so the best month makes 1.9 times the worst. November to March brings in 37% of the year's output in Stevens County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 2.34 m/s | 88 kWh | $13 |
| February | 2.46 m/s | 97 kWh | $14 |
| March | 2.75 m/s | 163 kWh | $24 |
| April | 2.75 m/s | 158 kWh | $23 |
| May | 2.56 m/s | 125 kWh | $18 |
| June | 2.53 m/s | 116 kWh | $17 |
| July | 2.64 m/s | 141 kWh | $20 |
| August | 2.58 m/s | 128 kWh | $18 |
| September | 2.61 m/s | 130 kWh | $19 |
| October | 2.58 m/s | 128 kWh | $18 |
| November | 2.47 m/s | 106 kWh | $15 |
| December | 2.39 m/s | 96 kWh | $14 |
What a taller tower would buy
Measured at 10 m the wind in Stevens County averages 1.69 m/s; at 50 m it is 3.09 m/s. That gives a shear exponent of 0.375, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 794 to 2,875 kWh a year, 262% 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 | 2.19 m/s | 794 kWh | over 100 years |
| 30 m | 2.55 m/s | 1,459 kWh | over 100 years |
| 40 m | 2.84 m/s | 2,157 kWh | over 100 years |
| 50 m | 3.09 m/s | 2,875 kWh | over 100 years |
Counties around Stevens County
3 of the 6 closest counties are windier at turbine height; the windiest, Lincoln County, averages 4.88 m/s.
- Pend Oreille County, WA: 2.48 m/s, 1,310 kWh, payback over 100 years (30 mi)
- Ferry County, WA: 2.74 m/s, 1,895 kWh, payback over 100 years (32 mi)
- Bonner County, ID: 2.53 m/s, 1,413 kWh, payback over 100 years (57 mi)
- Spokane County, WA: 4.42 m/s, 8,865 kWh, payback 78 years (57 mi)
- Lincoln County, WA: 4.88 m/s, 11,734 kWh, payback 59 years (61 mi)
- Boundary County, ID: 2.41 m/s, 1,172 kWh, payback over 100 years (66 mi)
Sun versus wind in Stevens County
Stevens County gets 3.64 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,063 kWh a year; one kW of the turbine above makes 146. Kilowatt for kilowatt, panels make 7.3 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.