Wind Turbine Payback in Isanti County, MN
Wind turbine payback in Isanti 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 Isanti County, MN averages 5.96 m/s (13.3 mph). A 10 kW turbine there would make about 19,408 kWh a year, worth $3,191 at MN's 16.44¢/kWh. Against an installed cost of about $100,000, that is a payback of 31 years, and the turbine is built to last about 20.
What to do in Isanti County
A home turbine is not worth buying for savings in Isanti County unless your spot is far windier than the county average, 7.5 m/s at the hub against 5.96 m/s here. Per kW, solar panels would make about 1,110 kWh a year here against the turbine's 1,941, so get a solar quote first.
What would have to change
- Power would have to cost 26¢/kWh, 1.6 times what MN pays now.
- Or the average wind at the hub would have to be 7.5 m/s instead of 5.96. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MN
Isanti County is the 901st windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in MN is Lincoln County at 6.68 m/s, payback 25 years.
Month by month in Isanti County
April is the strongest month here, at 6.57 m/s and about 1,966 kWh. July is the weakest, 5.02 m/s and 1,075 kWh, so the best month makes 1.8 times the worst. November to March brings in 45% of the year's output in Isanti County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.25 m/s | 1,830 kWh | $301 |
| February | 6.37 m/s | 1,724 kWh | $283 |
| March | 6.26 m/s | 1,836 kWh | $302 |
| April | 6.57 m/s | 1,966 kWh | $323 |
| May | 6.13 m/s | 1,757 kWh | $289 |
| June | 5.60 m/s | 1,377 kWh | $226 |
| July | 5.02 m/s | 1,075 kWh | $177 |
| August | 5.09 m/s | 1,117 kWh | $184 |
| September | 5.96 m/s | 1,597 kWh | $263 |
| October | 6.28 m/s | 1,853 kWh | $305 |
| November | 6.16 m/s | 1,717 kWh | $282 |
| December | 5.95 m/s | 1,645 kWh | $270 |
What a taller tower would buy
Measured at 10 m the wind in Isanti County averages 4.66 m/s; at 50 m it is 6.69 m/s. That gives a shear exponent of 0.225, typical of ordinary open country. Going from 20 m to 50 m takes output from 15,631 to 24,801 kWh a year, 59% 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 | 5.44 m/s | 15,631 kWh | 39 years |
| 30 m | 5.96 m/s | 19,435 kWh | 31 years |
| 40 m | 6.36 m/s | 22,391 kWh | 27 years |
| 50 m | 6.69 m/s | 24,801 kWh | 25 years |
Counties around Isanti County
4 of the 6 closest counties are windier at turbine height; the windiest, Mille Lacs County, averages 6.32 m/s.
- Chisago County, MN: 5.96 m/s, 19,408 kWh, payback 31 years (19 mi)
- Anoka County, MN: 5.96 m/s, 19,408 kWh, payback 31 years (20 mi)
- Sherburne County, MN: 6.13 m/s, 20,668 kWh, payback 29 years (24 mi)
- Kanabec County, MN: 6.14 m/s, 20,742 kWh, payback 29 years (27 mi)
- Mille Lacs County, MN: 6.32 m/s, 22,077 kWh, payback 28 years (30 mi)
- Benton County, MN: 6.13 m/s, 20,668 kWh, payback 29 years (35 mi)
Sun versus wind in Isanti County
Isanti County gets 3.8 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,110 kWh a year; one kW of the turbine above makes 1,941. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.7 times. 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.