Wind Turbine Payback in Cass County, ND
Wind turbine payback in Cass 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 Cass County, ND averages 6.35 m/s (14.2 mph). A 10 kW turbine there would make about 22,299 kWh a year, worth $2,778 at ND's 12.46¢/kWh. Against an installed cost of about $100,000, that is a payback of 36 years, and the turbine is built to last about 20.
What to do in Cass County
A home turbine is not worth buying for savings in Cass County unless your spot is far windier than the county average, 9.1 m/s at the hub against 6.35 m/s here. Per kW, solar panels would make about 1,142 kWh a year here against the turbine's 2,230, so get a solar quote first.
What would have to change
- Power would have to cost 22¢/kWh, 1.8 times what ND pays now.
- Or the average wind at the hub would have to be 9.1 m/s instead of 6.35. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of ND
Cass County is the 402nd windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in ND is Bowman County at 6.79 m/s, payback 31 years.
Month by month in Cass County
October is the strongest month here, at 6.91 m/s and about 2,243 kWh. July is the weakest, 5.50 m/s and 1,359 kWh, so the best month makes 1.7 times the worst. November to March brings in 42% of the year's output in Cass County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.37 m/s | 1,909 kWh | $238 |
| February | 6.33 m/s | 1,699 kWh | $212 |
| March | 6.54 m/s | 2,016 kWh | $251 |
| April | 6.84 m/s | 2,128 kWh | $265 |
| May | 6.70 m/s | 2,110 kWh | $263 |
| June | 6.04 m/s | 1,645 kWh | $205 |
| July | 5.50 m/s | 1,359 kWh | $169 |
| August | 5.62 m/s | 1,436 kWh | $179 |
| September | 6.48 m/s | 1,913 kWh | $238 |
| October | 6.91 m/s | 2,243 kWh | $279 |
| November | 6.56 m/s | 1,961 kWh | $244 |
| December | 6.26 m/s | 1,836 kWh | $229 |
What a taller tower would buy
Measured at 10 m the wind in Cass County averages 5.02 m/s; at 50 m it is 7.08 m/s. That gives a shear exponent of 0.214, typical of ordinary open country. Going from 20 m to 50 m takes output from 18,369 to 27,613 kWh a year, 50% 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 | 5.82 m/s | 18,369 kWh | 44 years |
| 30 m | 6.35 m/s | 22,276 kWh | 36 years |
| 40 m | 6.75 m/s | 25,238 kWh | 32 years |
| 50 m | 7.08 m/s | 27,613 kWh | 29 years |
Counties around Cass County
4 of the 6 closest counties are windier at turbine height; the windiest, Clay County, averages 6.45 m/s.
- Clay County, MN: 6.45 m/s, 23,038 kWh, payback 26 years (36 mi)
- Traill County, ND: 6.29 m/s, 21,855 kWh, payback 37 years (36 mi)
- Ransom County, ND: 6.28 m/s, 21,781 kWh, payback 37 years (38 mi)
- Barnes County, ND: 6.44 m/s, 22,964 kWh, payback 35 years (39 mi)
- Steele County, ND: 6.41 m/s, 22,743 kWh, payback 35 years (42 mi)
- Norman County, MN: 6.37 m/s, 22,447 kWh, payback 27 years (46 mi)
Sun versus wind in Cass County
Cass County gets 3.91 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,142 kWh a year; one kW of the turbine above makes 2,230. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 2.0 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.