TurbinePayback

Wind Turbine Payback in Franklin County, ME

Wind turbine payback in Franklin 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 Franklin County, ME averages 3.87 m/s (8.7 mph). A 10 kW turbine there would make about 5,942 kWh a year, worth $1,796 at ME's 30.23¢/kWh. Against an installed cost of about $100,000, that is a payback of 56 years, and the turbine is built to last about 20.

What to do in Franklin County

A home turbine is not worth buying for savings in Franklin County unless your spot is far windier than the county average, 5.6 m/s at the hub against 3.87 m/s here. Per kW, solar panels would make about 1,063 kWh a year here against the turbine's 594, so get a solar quote first.

What would have to change

Against the rest of ME

Franklin County is the 2,157th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in ME is Knox County at 6.26 m/s, payback 15 years.

Month by month in Franklin County

March is the strongest month here, at 4.71 m/s and about 905 kWh. August is the weakest, 3.01 m/s and 223 kWh, so the best month makes 4.1 times the worst. November to March brings in 60% of the year's output in Franklin County.

MonthWind at 30 mOutputWorth
January4.55 m/s818 kWh$247
February4.86 m/s891 kWh$269
March4.71 m/s905 kWh$274
April4.33 m/s688 kWh$208
May3.61 m/s405 kWh$122
June3.26 m/s283 kWh$86
July3.02 m/s227 kWh$69
August3.01 m/s223 kWh$67
September3.24 m/s276 kWh$83
October3.69 m/s435 kWh$132
November3.94 m/s516 kWh$156
December4.24 m/s664 kWh$201

What a taller tower would buy

Measured at 10 m the wind in Franklin County averages 2.55 m/s; at 50 m it is 4.69 m/s. That gives a shear exponent of 0.379, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 3,627 to 10,508 kWh a year, 190% 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 m3.31 m/s3,627 kWh91 years
30 m3.86 m/s5,916 kWh56 years
40 m4.31 m/s8,231 kWh40 years
50 m4.69 m/s10,508 kWh32 years

Counties around Franklin County

1 of the 6 closest counties is windier at turbine height; the windiest, Somerset County, averages 3.92 m/s.

Sun versus wind in Franklin County

Franklin County gets 3.64 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,063 kWh a year; one kW of the turbine above makes 594. Kilowatt for kilowatt, panels make 1.8 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.