Wind Turbine Payback in Clackamas County, OR
Wind turbine payback in Clackamas 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 Clackamas County, OR averages 3.23 m/s (7.2 mph). A 10 kW turbine there would make about 3,333 kWh a year, worth $515 at OR's 15.46¢/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 Clackamas County
A home turbine is not worth buying for savings in Clackamas County unless your spot is far windier than the county average, 7.8 m/s at the hub against 3.23 m/s here. Per kW, solar panels would make about 1,072 kWh a year here against the turbine's 333, so get a solar quote first.
What would have to change
- Power would have to cost 150¢/kWh, 9.7 times what OR pays now.
- Or the average wind at the hub would have to be 7.8 m/s instead of 3.23. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of OR
Clackamas County is the 2,844th 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 Clackamas County
December is the strongest month here, at 4.13 m/s and about 616 kWh. July is the weakest, 2.34 m/s and 89 kWh, so the best month makes 6.9 times the worst. November to March brings in 68% of the year's output in Clackamas County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.11 m/s | 608 kWh | $94 |
| February | 3.69 m/s | 392 kWh | $61 |
| March | 3.60 m/s | 404 kWh | $62 |
| April | 3.12 m/s | 244 kWh | $38 |
| May | 2.68 m/s | 148 kWh | $23 |
| June | 2.62 m/s | 132 kWh | $20 |
| July | 2.34 m/s | 89 kWh | $14 |
| August | 2.43 m/s | 103 kWh | $16 |
| September | 2.75 m/s | 158 kWh | $24 |
| October | 3.33 m/s | 311 kWh | $48 |
| November | 3.96 m/s | 523 kWh | $81 |
| December | 4.13 m/s | 616 kWh | $95 |
What a taller tower would buy
Measured at 10 m the wind in Clackamas County averages 2.11 m/s; at 50 m it is 3.93 m/s. That gives a shear exponent of 0.386, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 1,943 to 6,231 kWh a year, 221% 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 | 2.76 m/s | 1,943 kWh | over 100 years |
| 30 m | 3.23 m/s | 3,322 kWh | over 100 years |
| 40 m | 3.61 m/s | 4,760 kWh | over 100 years |
| 50 m | 3.93 m/s | 6,231 kWh | over 100 years |
Counties around Clackamas County
2 of the 6 closest counties are windier at turbine height; the windiest, Wasco County, averages 3.62 m/s.
- Marion County, OR: 3.23 m/s, 3,333 kWh, payback over 100 years (26 mi)
- Multnomah County, OR: 3.39 m/s, 3,905 kWh, payback over 100 years (29 mi)
- Hood River County, OR: 3.14 m/s, 3,034 kWh, payback over 100 years (36 mi)
- Clark County, WA: 2.96 m/s, 2,484 kWh, payback over 100 years (45 mi)
- Linn County, OR: 2.9 m/s, 2,315 kWh, payback over 100 years (49 mi)
- Wasco County, OR: 3.62 m/s, 4,820 kWh, payback over 100 years (50 mi)
Sun versus wind in Clackamas County
Clackamas County gets 3.67 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,072 kWh a year; one kW of the turbine above makes 333. Kilowatt for kilowatt, panels make 3.2 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.