Wind Turbine Payback in Philadelphia County, PA
Wind turbine payback in Philadelphia 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 Philadelphia County, PA averages 4.74 m/s (10.6 mph). A 10 kW turbine there would make about 10,826 kWh a year, worth $2,287 at PA's 21.13¢/kWh. Against an installed cost of about $100,000, that is a payback of 44 years, and the turbine is built to last about 20.
What to do in Philadelphia County
A home turbine is not worth buying for savings in Philadelphia County unless your spot is far windier than the county average, 6.5 m/s at the hub against 4.74 m/s here. Per kW, solar panels would make about 1,127 kWh a year here against the turbine's 1,083, so get a solar quote first.
What would have to change
- Power would have to cost 46¢/kWh, 2.2 times what PA pays now.
- Or the average wind at the hub would have to be 6.5 m/s instead of 4.74. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of PA
Philadelphia County is the 1,592nd windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. It is the windiest county in PA.
Month by month in Philadelphia County
March is the strongest month here, at 5.52 m/s and about 1,377 kWh. August is the weakest, 3.69 m/s and 433 kWh, so the best month makes 3.2 times the worst. November to March brings in 56% of the year's output in Philadelphia County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.41 m/s | 1,309 kWh | $277 |
| February | 5.59 m/s | 1,277 kWh | $270 |
| March | 5.52 m/s | 1,377 kWh | $291 |
| April | 5.29 m/s | 1,197 kWh | $253 |
| May | 4.45 m/s | 768 kWh | $162 |
| June | 4.06 m/s | 567 kWh | $120 |
| July | 3.76 m/s | 463 kWh | $98 |
| August | 3.69 m/s | 433 kWh | $91 |
| September | 4.12 m/s | 590 kWh | $125 |
| October | 4.82 m/s | 963 kWh | $203 |
| November | 5.04 m/s | 1,055 kWh | $223 |
| December | 5.23 m/s | 1,201 kWh | $254 |
What a taller tower would buy
Measured at 10 m the wind in Philadelphia County averages 3.42 m/s; at 50 m it is 5.52 m/s. That gives a shear exponent of 0.297, typical of ordinary open country. Going from 20 m to 50 m takes output from 7,650 to 16,181 kWh a year, 112% 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 | 4.2 m/s | 7,650 kWh | 62 years |
| 30 m | 4.74 m/s | 10,845 kWh | 44 years |
| 40 m | 5.17 m/s | 13,671 kWh | 35 years |
| 50 m | 5.52 m/s | 16,181 kWh | 29 years |
Counties around Philadelphia County
2 of the 6 closest counties are windier at turbine height; the windiest, Gloucester County, averages 5.8 m/s.
- Delaware County, PA: 3.92 m/s, 6,182 kWh, payback 77 years (15 mi)
- Camden County, NJ: 4.74 m/s, 10,826 kWh, payback 38 years (17 mi)
- Montgomery County, PA: 3.92 m/s, 6,182 kWh, payback 77 years (19 mi)
- Gloucester County, NJ: 5.8 m/s, 18,226 kWh, payback 23 years (20 mi)
- Bucks County, PA: 3.54 m/s, 4,489 kWh, payback over 100 years (23 mi)
- Burlington County, NJ: 5.47 m/s, 15,821 kWh, payback 26 years (27 mi)
Sun versus wind in Philadelphia County
Philadelphia County gets 3.86 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,127 kWh a year; one kW of the turbine above makes 1,083. Kilowatt for kilowatt, panels make 1.0 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.