Wind Turbine Payback in Cape May County, NJ
Wind turbine payback in Cape May County
Only just. The money comes back late in the turbine's life.
At 30 m, the height a home turbine tower usually reaches, the wind in Cape May County, NJ averages 6.6 m/s (14.8 mph). A 10 kW turbine there would make about 24,142 kWh a year, worth $5,816 at NJ's 24.09¢/kWh. Against an installed cost of about $100,000, that is a payback of 17 years, and the turbine is built to last about 20.
What to do in Cape May County
It is close enough that your own site decides it. If you have open land with no trees or buildings upwind, ask an installer to log the wind at 30 m or higher; anything above 6.1 m/s pays back in time. Per kW, solar panels would make about 1,186 kWh a year here against the turbine's 2,414, so get a solar quote first.
What would have to change
- Power already costs enough here: break-even is 21¢/kWh and NJ pays 24.09¢.
- The wind clears the break-even speed of 6.1 m/s at today's price.
Against the rest of NJ
Cape May County is the 114th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. It is the windiest county in NJ.
Month by month in Cape May County
January is the strongest month here, at 7.62 m/s and about 2,664 kWh. August is the weakest, 4.98 m/s and 1,055 kWh, so the best month makes 2.5 times the worst. November to March brings in 52% of the year's output in Cape May County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 7.62 m/s | 2,664 kWh | $642 |
| February | 7.59 m/s | 2,387 kWh | $575 |
| March | 7.52 m/s | 2,606 kWh | $628 |
| April | 7.37 m/s | 2,439 kWh | $588 |
| May | 6.26 m/s | 1,836 kWh | $442 |
| June | 5.64 m/s | 1,401 kWh | $338 |
| July | 5.11 m/s | 1,130 kWh | $272 |
| August | 4.98 m/s | 1,055 kWh | $254 |
| September | 5.74 m/s | 1,462 kWh | $352 |
| October | 6.77 m/s | 2,153 kWh | $519 |
| November | 7.18 m/s | 2,328 kWh | $561 |
| December | 7.45 m/s | 2,563 kWh | $617 |
What a taller tower would buy
Measured at 10 m the wind in Cape May County averages 5.55 m/s; at 50 m it is 7.15 m/s. That gives a shear exponent of 0.157, typical of very open, smooth ground where height adds little. Going from 20 m to 50 m takes output from 21,128 to 28,109 kWh a year, 33% 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 | 6.19 m/s | 21,128 kWh | 20 years |
| 30 m | 6.6 m/s | 24,135 kWh | 17 years |
| 40 m | 6.9 m/s | 26,353 kWh | 16 years |
| 50 m | 7.15 m/s | 28,109 kWh | 15 years |
Counties around Cape May County
None of the 6 closest counties is windier than Cape May County.
- Cumberland County, NJ: 5.8 m/s, 18,226 kWh, payback 23 years (22 mi)
- Atlantic County, NJ: 6.47 m/s, 23,186 kWh, payback 18 years (29 mi)
- Kent County, DE: 5.7 m/s, 17,492 kWh, payback 32 years (35 mi)
- Sussex County, DE: 5.87 m/s, 18,742 kWh, payback 30 years (39 mi)
- Salem County, NJ: 5.23 m/s, 14,116 kWh, payback 29 years (43 mi)
- Gloucester County, NJ: 5.8 m/s, 18,226 kWh, payback 23 years (47 mi)
Sun versus wind in Cape May County
Cape May County gets 4.06 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,186 kWh a year; one kW of the turbine above makes 2,414. 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.