TurbinePayback

Wind Turbine Payback in Placer County, CA

Wind turbine payback in Placer 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 Placer County, CA averages 3.43 m/s (7.7 mph). A 10 kW turbine there would make about 4,056 kWh a year, worth $1,321 at CA's 32.58¢/kWh. Against an installed cost of about $100,000, that is a payback of 76 years, and the turbine is built to last about 20.

What to do in Placer County

A home turbine is not worth buying for savings in Placer County unless your spot is far windier than the county average, 5.4 m/s at the hub against 3.43 m/s here. Per kW, solar panels would make about 1,501 kWh a year here against the turbine's 406, so get a solar quote first.

What would have to change

Against the rest of CA

Placer County is the 2,587th 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 Placer County

December is the strongest month here, at 3.96 m/s and about 541 kWh. July is the weakest, 2.88 m/s and 192 kWh, so the best month makes 2.8 times the worst. November to March brings in 56% of the year's output in Placer County.

MonthWind at 30 mOutputWorth
January3.91 m/s520 kWh$169
February3.86 m/s451 kWh$147
March3.66 m/s422 kWh$137
April3.36 m/s312 kWh$102
May3.17 m/s265 kWh$86
June3.12 m/s243 kWh$79
July2.88 m/s192 kWh$63
August2.95 m/s208 kWh$68
September3.24 m/s278 kWh$91
October3.42 m/s341 kWh$111
November3.63 m/s400 kWh$130
December3.96 m/s541 kWh$176

What a taller tower would buy

Measured at 10 m the wind in Placer County averages 2.37 m/s; at 50 m it is 4.07 m/s. That gives a shear exponent of 0.336, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 2,576 to 6,934 kWh a year, 169% more, before counting the extra cost of the taller tower. Why tower height decides it explains the shear behind these numbers.

Hub heightAverage windOutputPayback
20 m2.99 m/s2,576 kWhover 100 years
30 m3.43 m/s4,049 kWh76 years
40 m3.78 m/s5,504 kWh56 years
50 m4.07 m/s6,934 kWh44 years

Counties around Placer County

3 of the 6 closest counties are windier at turbine height; the windiest, Carson City, averages 3.75 m/s.

Sun versus wind in Placer County

Placer County gets 5.14 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,501 kWh a year; one kW of the turbine above makes 406. Kilowatt for kilowatt, panels make 3.7 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.