Wind Turbine Payback in Grand County, CO
Wind turbine payback in Grand 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 Grand County, CO averages 3.36 m/s (7.5 mph). A 10 kW turbine there would make about 3,794 kWh a year, worth $637 at CO's 16.8¢/kWh. Against an installed cost of about $100,000, that is a payback of over 100 years, and the turbine is built to last about 20.
What to do in Grand County
A home turbine is not worth buying for savings in Grand County unless your spot is far windier than the county average, 7.4 m/s at the hub against 3.36 m/s here. Per kW, solar panels would make about 1,372 kWh a year here against the turbine's 379, so get a solar quote first.
What would have to change
- Power would have to cost 132¢/kWh, 7.8 times what CO pays now.
- Or the average wind at the hub would have to be 7.4 m/s instead of 3.36. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of CO
Grand County is the 2,665th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in CO is Baca County at 6.65 m/s, payback 24 years.
Month by month in Grand County
April is the strongest month here, at 3.84 m/s and about 476 kWh. July is the weakest, 2.56 m/s and 125 kWh, so the best month makes 3.8 times the worst. November to March brings in 54% of the year's output in Grand County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.64 m/s | 415 kWh | $70 |
| February | 3.82 m/s | 439 kWh | $74 |
| March | 3.75 m/s | 459 kWh | $77 |
| April | 3.84 m/s | 476 kWh | $80 |
| May | 3.29 m/s | 301 kWh | $51 |
| June | 3.17 m/s | 258 kWh | $43 |
| July | 2.56 m/s | 125 kWh | $21 |
| August | 2.58 m/s | 128 kWh | $22 |
| September | 2.91 m/s | 193 kWh | $32 |
| October | 3.43 m/s | 343 kWh | $58 |
| November | 3.65 m/s | 408 kWh | $69 |
| December | 3.70 m/s | 440 kWh | $74 |
What a taller tower would buy
Measured at 10 m the wind in Grand County averages 2.32 m/s; at 50 m it is 3.99 m/s. That gives a shear exponent of 0.337, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 2,398 to 6,527 kWh a year, 172% 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 | 2.93 m/s | 2,398 kWh | over 100 years |
| 30 m | 3.36 m/s | 3,790 kWh | over 100 years |
| 40 m | 3.7 m/s | 5,169 kWh | over 100 years |
| 50 m | 3.99 m/s | 6,527 kWh | 91 years |
Counties around Grand County
5 of the 6 closest counties are windier at turbine height; the windiest, Gilpin County, averages 4.87 m/s.
- Summit County, CO: 3.59 m/s, 4,694 kWh, payback over 100 years (34 mi)
- Gilpin County, CO: 4.87 m/s, 11,668 kWh, payback 51 years (35 mi)
- Clear Creek County, CO: 4.63 m/s, 10,132 kWh, payback 59 years (37 mi)
- Boulder County, CO: 4.87 m/s, 11,668 kWh, payback 51 years (38 mi)
- Jackson County, CO: 3.69 m/s, 5,121 kWh, payback over 100 years (40 mi)
- Eagle County, CO: 3.34 m/s, 3,720 kWh, payback over 100 years (46 mi)
Sun versus wind in Grand County
Grand County gets 4.7 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,372 kWh a year; one kW of the turbine above makes 379. Kilowatt for kilowatt, panels make 3.6 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.