Wind Turbine Payback in Mendocino County, CA
Wind turbine payback in Mendocino 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 Mendocino County, CA averages 3.87 m/s (8.7 mph). A 10 kW turbine there would make about 5,942 kWh a year, worth $1,936 at CA's 32.58¢/kWh. Against an installed cost of about $100,000, that is a payback of 52 years, and the turbine is built to last about 20.
What to do in Mendocino County
A home turbine is not worth buying for savings in Mendocino County unless your spot is far windier than the county average, 5.4 m/s at the hub against 3.87 m/s here. Per kW, solar panels would make about 1,437 kWh a year here against the turbine's 594, so get a solar quote first.
What would have to change
- Power would have to cost 84¢/kWh, 2.6 times what CA pays now.
- Or the average wind at the hub would have to be 5.4 m/s instead of 3.87. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of CA
Mendocino County is the 2,157th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in CA is San Francisco County at 6.53 m/s, payback 13 years.
Month by month in Mendocino County
June is the strongest month here, at 4.37 m/s and about 703 kWh. August is the weakest, 3.36 m/s and 323 kWh, so the best month makes 2.2 times the worst. November to March brings in 46% of the year's output in Mendocino County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.85 m/s | 495 kWh | $161 |
| February | 4.20 m/s | 583 kWh | $190 |
| March | 4.07 m/s | 589 kWh | $192 |
| April | 3.97 m/s | 529 kWh | $172 |
| May | 4.03 m/s | 574 kWh | $187 |
| June | 4.37 m/s | 703 kWh | $229 |
| July | 3.60 m/s | 401 kWh | $131 |
| August | 3.36 m/s | 323 kWh | $105 |
| September | 3.49 m/s | 352 kWh | $115 |
| October | 3.58 m/s | 395 kWh | $129 |
| November | 3.73 m/s | 436 kWh | $142 |
| December | 4.26 m/s | 675 kWh | $220 |
What a taller tower would buy
Measured at 10 m the wind in Mendocino County averages 3.05 m/s; at 50 m it is 4.33 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 4,513 to 8,346 kWh a year, 85% 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 | 3.55 m/s | 4,513 kWh | 68 years |
| 30 m | 3.87 m/s | 5,959 kWh | 52 years |
| 40 m | 4.12 m/s | 7,218 kWh | 43 years |
| 50 m | 4.33 m/s | 8,346 kWh | 37 years |
Counties around Mendocino County
4 of the 6 closest counties are windier at turbine height; the windiest, Sonoma County, averages 4.66 m/s.
- Lake County, CA: 3.92 m/s, 6,182 kWh, payback 50 years (44 mi)
- Glenn County, CA: 3.8 m/s, 5,614 kWh, payback 55 years (57 mi)
- Colusa County, CA: 3.92 m/s, 6,182 kWh, payback 50 years (67 mi)
- Sonoma County, CA: 4.66 m/s, 10,320 kWh, payback 30 years (69 mi)
- Tehama County, CA: 3.89 m/s, 6,037 kWh, payback 51 years (80 mi)
- Trinity County, CA: 2.43 m/s, 1,211 kWh, payback over 100 years (86 mi)
Sun versus wind in Mendocino County
Mendocino County gets 4.92 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,437 kWh a year; one kW of the turbine above makes 594. Kilowatt for kilowatt, panels make 2.4 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.