Wind Turbine Payback in Imperial County, CA
Wind turbine payback in Imperial 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 Imperial County, CA averages 4.5 m/s (10.1 mph). A 10 kW turbine there would make about 9,339 kWh a year, worth $3,043 at CA's 32.58¢/kWh. Against an installed cost of about $100,000, that is a payback of 33 years, and the turbine is built to last about 20.
What to do in Imperial County
A home turbine is not worth buying for savings in Imperial County unless your spot is far windier than the county average, 5.4 m/s at the hub against 4.5 m/s here. Per kW, solar panels would make about 1,732 kWh a year here against the turbine's 934, so get a solar quote first.
What would have to change
- Power would have to cost 54¢/kWh, 1.6 times what CA pays now.
- Or the average wind at the hub would have to be 5.4 m/s instead of 4.5. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of CA
Imperial County is the 1,743rd 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 Imperial County
May is the strongest month here, at 5.33 m/s and about 1,257 kWh. December is the weakest, 4.01 m/s and 562 kWh, so the best month makes 2.2 times the worst. November to March brings in 34% of the year's output in Imperial County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.05 m/s | 582 kWh | $190 |
| February | 4.19 m/s | 580 kWh | $189 |
| March | 4.73 m/s | 915 kWh | $298 |
| April | 5.35 m/s | 1,232 kWh | $401 |
| May | 5.33 m/s | 1,257 kWh | $410 |
| June | 5.07 m/s | 1,067 kWh | $348 |
| July | 4.39 m/s | 737 kWh | $240 |
| August | 4.14 m/s | 618 kWh | $201 |
| September | 4.20 m/s | 626 kWh | $204 |
| October | 4.39 m/s | 737 kWh | $240 |
| November | 4.09 m/s | 578 kWh | $188 |
| December | 4.01 m/s | 562 kWh | $183 |
What a taller tower would buy
Measured at 10 m the wind in Imperial County averages 3.61 m/s; at 50 m it is 4.98 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 7,334 to 12,400 kWh a year, 69% 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 | 4.15 m/s | 7,334 kWh | 42 years |
| 30 m | 4.5 m/s | 9,317 kWh | 33 years |
| 40 m | 4.76 m/s | 10,971 kWh | 28 years |
| 50 m | 4.98 m/s | 12,400 kWh | 25 years |
Counties around Imperial County
2 of the 6 closest counties are windier at turbine height; the windiest, Yuma County, averages 4.57 m/s.
- Riverside County, CA: 3.95 m/s, 6,329 kWh, payback 49 years (60 mi)
- San Diego County, CA: 3.87 m/s, 5,942 kWh, payback 52 years (82 mi)
- Yuma County, AZ: 4.57 m/s, 9,763 kWh, payback 67 years (86 mi)
- La Paz County, AZ: 4.54 m/s, 9,580 kWh, payback 68 years (90 mi)
- San Bernardino County, CA: 4.3 m/s, 8,176 kWh, payback 38 years (134 mi)
- Orange County, CA: 3.16 m/s, 3,099 kWh, payback 99 years (146 mi)
Sun versus wind in Imperial County
Imperial County gets 5.93 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,732 kWh a year; one kW of the turbine above makes 934. Kilowatt for kilowatt, panels make 1.9 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.