An iconic image of the old farmstead is a lovely windmill turning slowly, driving some unseen mechanism or well pump. This free and naturally occurring power source has been largely forgotten as access to the power grid and electric motors have replaced mechanical devices on the farm. But as we see the collateral costs of our dependence on fossil fuels play out before us, alternative energy production begins to hold promise to fulfill fundamental land management goals of energy independence and resource conservation.
Unfortunately, the southeast United States region as a whole is not the best area for harvesting wind energy due to low average annual wind speeds. However, there are some places that do have predictable winds due to hilly or mountainous terrain or daily temperature inversion winds. The best way to check your property’s wind harnessing potential is online (see wind map) or at your local airport. More specific wind studies should involve investment in a personal weather station installed at the site and mounted around thirty feet above grade. With a wind anemometer you can keep records for one year to determine the best turbine system to purchase and install. The average wind speed in the southeast is less than nine miles per hour and the minimum effective wind speed for power generation is eleven miles per hour, so choosing a low speed system would be appropriate in the southern states. Also, there are numerous high tech designs for wind mills, each with various efficiency characteristics based on wind speed.
Beyond the technical aspects of these machines are questions to answer such as: cost per kilowatt, tax incentives, noise and visual aesthetics, etc. Noise from modern turbines are negligible, especially with smaller machines as their mounting height of 33+ feet reduces sound at ground level. Tax incentives are similar to other alternative power investment tax credits of 30% of project cash to you. Wind power is less costly than solar (a typical residential unit is around $15,000) due to the high cost of solar cell manufacturing.
The aesthetic debate about wind mills is difficult for me to reconcile. On the one hand, my thoughts are based on a history of wind machinery on the farm (there is something romantic and pleasing about this symbol of land productivity) but I can also see how turbines would clutter the sylvan landscape. I think if you are going to install a windmill, its location in association with other farm buildings would be important to consider for energy for efficiency and for minimizing human impact on the surrounding terrain.
Generally speaking, wind power in the southeast has limited potential for consistent electrical power generation except in localized special conditions. It does have promise (along with other systems such as solar and geothermal) to be part of a total solution to reduce dependence on public utilities and therefore accomplish an honorable goal of energy independence and good land stewardship. There is no single source “magic bullet” to achieve our farm energy goals, it will be necessary to invest in multiple systems, integrated and applied where location makes it possible. Wind power, an age old means to leverage free energy from the environment, is back in our farm future.