Wind Turbine Payback in Solano County, CA
Wind turbine payback in Solano 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 Solano County, CA averages 4.42 m/s (9.9 mph). A 10 kW turbine there would make about 8,865 kWh a year, worth $2,888 at CA's 32.58¢/kWh. Against an installed cost of about $100,000, that is a payback of 35 years, and the turbine is built to last about 20.
What to do in Solano County
A home turbine is not worth buying for savings in Solano County unless your spot is far windier than the county average, 5.4 m/s at the hub against 4.42 m/s here. Per kW, solar panels would make about 1,527 kWh a year here against the turbine's 887, so get a solar quote first.
What would have to change
- Power would have to cost 56¢/kWh, 1.7 times what CA pays now.
- Or the average wind at the hub would have to be 5.4 m/s instead of 4.42. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of CA
Solano County is the 1,799th 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 Solano County
May is the strongest month here, at 4.62 m/s and about 857 kWh. November is the weakest, 4.09 m/s and 577 kWh, so the best month makes 1.5 times the worst. November to March brings in 40% of the year's output in Solano County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.18 m/s | 636 kWh | $207 |
| February | 4.59 m/s | 757 kWh | $247 |
| March | 4.44 m/s | 760 kWh | $248 |
| April | 4.60 m/s | 816 kWh | $266 |
| May | 4.62 m/s | 857 kWh | $279 |
| June | 4.58 m/s | 806 kWh | $263 |
| July | 4.60 m/s | 843 kWh | $275 |
| August | 4.44 m/s | 760 kWh | $248 |
| September | 4.13 m/s | 596 kWh | $194 |
| October | 4.18 m/s | 636 kWh | $207 |
| November | 4.09 m/s | 577 kWh | $188 |
| December | 4.56 m/s | 824 kWh | $268 |
What a taller tower would buy
Measured at 10 m the wind in Solano County averages 3.47 m/s; at 50 m it is 4.94 m/s. That gives a shear exponent of 0.219, typical of ordinary open country. Going from 20 m to 50 m takes output from 6,789 to 12,132 kWh a year, 79% 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 | 4.04 m/s | 6,789 kWh | 45 years |
| 30 m | 4.42 m/s | 8,848 kWh | 35 years |
| 40 m | 4.7 m/s | 10,599 kWh | 29 years |
| 50 m | 4.94 m/s | 12,132 kWh | 25 years |
Counties around Solano County
1 of the 6 closest counties is windier at turbine height; the windiest, Contra Costa County, averages 4.85 m/s.
- Contra Costa County, CA: 4.85 m/s, 11,537 kWh, payback 27 years (24 mi)
- Napa County, CA: 3.97 m/s, 6,428 kWh, payback 48 years (27 mi)
- Yolo County, CA: 4.42 m/s, 8,865 kWh, payback 35 years (29 mi)
- Sacramento County, CA: 3.82 m/s, 5,707 kWh, payback 54 years (35 mi)
- Alameda County, CA: 4.17 m/s, 7,461 kWh, payback 41 years (43 mi)
- San Joaquin County, CA: 4.09 m/s, 7,038 kWh, payback 44 years (43 mi)
Sun versus wind in Solano County
Solano County gets 5.23 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,527 kWh a year; one kW of the turbine above makes 887. Kilowatt for kilowatt, panels make 1.7 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.