Wind Turbine Payback in San Bernardino County, CA
Wind turbine payback in San Bernardino 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 San Bernardino County, CA averages 4.3 m/s (9.6 mph). A 10 kW turbine there would make about 8,176 kWh a year, worth $2,664 at CA's 32.58¢/kWh. Against an installed cost of about $100,000, that is a payback of 38 years, and the turbine is built to last about 20.
What to do in San Bernardino County
A home turbine is not worth buying for savings in San Bernardino County unless your spot is far windier than the county average, 5.4 m/s at the hub against 4.3 m/s here. Per kW, solar panels would make about 1,720 kWh a year here against the turbine's 818, so get a solar quote first.
What would have to change
- Power would have to cost 61¢/kWh, 1.9 times what CA pays now.
- Or the average wind at the hub would have to be 5.4 m/s instead of 4.3. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of CA
San Bernardino County is the 1,894th 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 San Bernardino County
April is the strongest month here, at 5.16 m/s and about 1,118 kWh. November is the weakest, 3.86 m/s and 484 kWh, so the best month makes 2.3 times the worst. November to March brings in 36% of the year's output in San Bernardino County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.92 m/s | 526 kWh | $171 |
| February | 4.26 m/s | 608 kWh | $198 |
| March | 4.60 m/s | 844 kWh | $275 |
| April | 5.16 m/s | 1,118 kWh | $364 |
| May | 4.96 m/s | 1,041 kWh | $339 |
| June | 4.89 m/s | 968 kWh | $315 |
| July | 4.20 m/s | 648 kWh | $211 |
| August | 3.97 m/s | 544 kWh | $177 |
| September | 3.86 m/s | 484 kWh | $158 |
| October | 3.89 m/s | 511 kWh | $166 |
| November | 3.86 m/s | 484 kWh | $158 |
| December | 4.02 m/s | 567 kWh | $185 |
What a taller tower would buy
Measured at 10 m the wind in San Bernardino County averages 3.44 m/s; at 50 m it is 4.77 m/s. That gives a shear exponent of 0.203, typical of ordinary open country. Going from 20 m to 50 m takes output from 6,380 to 11,018 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 | 3.96 m/s | 6,380 kWh | 48 years |
| 30 m | 4.3 m/s | 8,177 kWh | 38 years |
| 40 m | 4.56 m/s | 9,694 kWh | 32 years |
| 50 m | 4.77 m/s | 11,018 kWh | 28 years |
Counties around San Bernardino County
2 of the 6 closest counties are windier at turbine height; the windiest, Clark County, averages 4.7 m/s.
- Riverside County, CA: 3.95 m/s, 6,329 kWh, payback 49 years (79 mi)
- Clark County, NV: 4.7 m/s, 10,571 kWh, payback 71 years (114 mi)
- Orange County, CA: 3.16 m/s, 3,099 kWh, payback 99 years (122 mi)
- Los Angeles County, CA: 3.34 m/s, 3,720 kWh, payback 83 years (127 mi)
- San Diego County, CA: 3.87 m/s, 5,942 kWh, payback 52 years (131 mi)
- Imperial County, CA: 4.5 m/s, 9,339 kWh, payback 33 years (134 mi)
Sun versus wind in San Bernardino County
San Bernardino County gets 5.89 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,720 kWh a year; one kW of the turbine above makes 818. 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.