Wind Turbine Payback in Alameda County, CA
Wind turbine payback in Alameda 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 Alameda County, CA averages 4.17 m/s (9.3 mph). A 10 kW turbine there would make about 7,461 kWh a year, worth $2,431 at CA's 32.58¢/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 Alameda County
A home turbine is not worth buying for savings in Alameda County unless your spot is far windier than the county average, 5.4 m/s at the hub against 4.17 m/s here. Per kW, solar panels would make about 1,553 kWh a year here against the turbine's 746, so get a solar quote first.
What would have to change
- Power would have to cost 67¢/kWh, 2.1 times what CA pays now.
- Or the average wind at the hub would have to be 5.4 m/s instead of 4.17. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of CA
Alameda County is the 1,965th 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 Alameda County
June is the strongest month here, at 4.69 m/s and about 866 kWh. November is the weakest, 3.65 m/s and 406 kWh, so the best month makes 2.1 times the worst. November to March brings in 36% of the year's output in Alameda County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.77 m/s | 463 kWh | $151 |
| February | 4.18 m/s | 577 kWh | $188 |
| March | 4.20 m/s | 647 kWh | $211 |
| April | 4.47 m/s | 752 kWh | $245 |
| May | 4.62 m/s | 857 kWh | $279 |
| June | 4.69 m/s | 866 kWh | $282 |
| July | 4.45 m/s | 768 kWh | $250 |
| August | 4.21 m/s | 651 kWh | $212 |
| September | 3.90 m/s | 500 kWh | $163 |
| October | 3.74 m/s | 453 kWh | $148 |
| November | 3.65 m/s | 406 kWh | $132 |
| December | 4.13 m/s | 614 kWh | $200 |
What a taller tower would buy
Measured at 10 m the wind in Alameda County averages 3.35 m/s; at 50 m it is 4.62 m/s. That gives a shear exponent of 0.200, typical of ordinary open country. Going from 20 m to 50 m takes output from 5,830 to 10,070 kWh a year, 73% 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 | 3.85 m/s | 5,830 kWh | 53 years |
| 30 m | 4.17 m/s | 7,468 kWh | 41 years |
| 40 m | 4.42 m/s | 8,855 kWh | 35 years |
| 50 m | 4.62 m/s | 10,070 kWh | 31 years |
Counties around Alameda County
3 of the 6 closest counties are windier at turbine height; the windiest, San Mateo County, averages 5.02 m/s.
- Contra Costa County, CA: 4.85 m/s, 11,537 kWh, payback 27 years (19 mi)
- San Mateo County, CA: 5.02 m/s, 12,670 kWh, payback 24 years (30 mi)
- Santa Clara County, CA: 3.46 m/s, 4,172 kWh, payback 74 years (32 mi)
- San Joaquin County, CA: 4.09 m/s, 7,038 kWh, payback 44 years (40 mi)
- Solano County, CA: 4.42 m/s, 8,865 kWh, payback 35 years (43 mi)
- Santa Cruz County, CA: 3.46 m/s, 4,172 kWh, payback 74 years (44 mi)
Sun versus wind in Alameda County
Alameda County gets 5.32 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,553 kWh a year; one kW of the turbine above makes 746. Kilowatt for kilowatt, panels make 2.1 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.