Wind Turbine Payback in Boulder County, CO
Wind turbine payback in Boulder 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 Boulder County, CO averages 4.87 m/s (10.9 mph). A 10 kW turbine there would make about 11,668 kWh a year, worth $1,960 at CO's 16.8¢/kWh. Against an installed cost of about $100,000, that is a payback of 51 years, and the turbine is built to last about 20.
What to do in Boulder County
A home turbine is not worth buying for savings in Boulder County unless your spot is far windier than the county average, 7.4 m/s at the hub against 4.87 m/s here. Per kW, solar panels would make about 1,337 kWh a year here against the turbine's 1,167, so get a solar quote first.
What would have to change
- Power would have to cost 43¢/kWh, 2.6 times what CO pays now.
- Or the average wind at the hub would have to be 7.4 m/s instead of 4.87. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of CO
Boulder County is the 1,524th 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 Boulder County
January is the strongest month here, at 6.36 m/s and about 1,901 kWh. July is the weakest, 3.34 m/s and 316 kWh, so the best month makes 6.0 times the worst. November to March brings in 65% of the year's output in Boulder County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.36 m/s | 1,901 kWh | $319 |
| February | 6.03 m/s | 1,526 kWh | $256 |
| March | 5.59 m/s | 1,420 kWh | $239 |
| April | 5.11 m/s | 1,092 kWh | $183 |
| May | 4.18 m/s | 637 kWh | $107 |
| June | 3.94 m/s | 515 kWh | $87 |
| July | 3.34 m/s | 316 kWh | $53 |
| August | 3.38 m/s | 327 kWh | $55 |
| September | 3.88 m/s | 491 kWh | $82 |
| October | 4.87 m/s | 990 kWh | $166 |
| November | 5.68 m/s | 1,426 kWh | $240 |
| December | 6.15 m/s | 1,765 kWh | $297 |
What a taller tower would buy
Measured at 10 m the wind in Boulder County averages 3.55 m/s; at 50 m it is 5.64 m/s. That gives a shear exponent of 0.288, typical of ordinary open country. Going from 20 m to 50 m takes output from 8,356 to 17,053 kWh a year, 104% 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 | 4.33 m/s | 8,356 kWh | 71 years |
| 30 m | 4.87 m/s | 11,658 kWh | 51 years |
| 40 m | 5.29 m/s | 14,530 kWh | 41 years |
| 50 m | 5.64 m/s | 17,053 kWh | 35 years |
Counties around Boulder County
1 of the 6 closest counties is windier at turbine height; the windiest, Jefferson County, averages 4.97 m/s.
- Gilpin County, CO: 4.87 m/s, 11,668 kWh, payback 51 years (18 mi)
- Broomfield County, CO: 4.76 m/s, 10,954 kWh, payback 54 years (21 mi)
- Clear Creek County, CO: 4.63 m/s, 10,132 kWh, payback 59 years (32 mi)
- Denver County, CO: 4.76 m/s, 10,954 kWh, payback 54 years (36 mi)
- Jefferson County, CO: 4.97 m/s, 12,333 kWh, payback 48 years (37 mi)
- Grand County, CO: 3.36 m/s, 3,794 kWh, payback over 100 years (38 mi)
Sun versus wind in Boulder County
Boulder County gets 4.58 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,337 kWh a year; one kW of the turbine above makes 1,167. Kilowatt for kilowatt, panels make 1.1 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.