About wind turbines: Where do I mount one?
Efficiency, safety and neighbors are key issues for wind power siting.
Fri, Sep 17, 2010 at 11:27 AM
So you studied the maps and collected local wind data. You know wind power is cost-effective in your area. Now it's time to site the turbine. Here is how to maximize efficiency and safety while being a good neighbor.
Get above the trees
The American Wind Energy Association recommends placing the bottom edge of the rotor blade at least 30 feet above any trees or buildings within a 500-foot radius. Such barriers slow wind speed and create turbulence, which causes undue wear on a turbine and reduces efficiency. Also, be sure to measure 30 feet from the expected full-growth height of any trees, not the current height.
Stay off the roof
Putting a turbine on top of the house might seem like an easy way to add a few feet, but experts advise against roof-mounted wind turbines. Some companies refuse to install roof-mounted turbines. They are typically noisy, unsafe and ineffective. Roofs are not built to withstand the weight of wind turbines, and vibrations from the turbine may be felt in the house. The roof also creates too much turbulence to allow the turbine to operate efficiently.
Mount a safe tower
Don't buy a top-shelf wind turbine and skimp on the tower. A poorly built or sited tower may pose safety hazards. Home wind turbines are typically placed on guyed-lattice towers, which look like radio broadcast towers. Steel cables help support a three-sided frame of metal strips. Guyed-lattice towers are the least expensive option, and they are relatively easy to install without building a thick foundation. However, guy wires extend in a radius of up to 75 percent of the tower height, so they require a relatively large space. Also consider a hinge at the bottom of the tower to lower the turbine for maintenance or during hurricanes and other hazardous weather.
Choose the right materials
Take care when choosing materials for the turbine and tower. Aluminum towers may be cheap, but they are liable to crack. Also, some metal rotor blades interfere with television and radio signals. Fiberglass is a better option.
Be a good neighbor
Minimize the aesthetic and sonic impacts of a wind turbine. Look for the Swift Wind Turbine and other models with quieter designs. Also consider compromising efficiency to keep from upsetting neighbors. Electric output increases exponentially with both wind speed and blade size. A tall tower with large rotor blades will generate more power, but will generate more complaints about blocking views or creating an eyesore.
Check local restrictions before mounting a wind turbine. Many cities require a zoning permit for home wind turbines, and they may impose height restrictions. Homeowners' associations may also forbid wind turbines.
A breezy alternative
Finally, if a wind turbine won't work on your property, you can still indirectly harness wind energy by purchasing wind power credits. At least 750 electric utilities charge an optional "green pricing" premium to offset the costs of building new wind farms and other renewable energy systems. The U.S. Department of Energy lists green pricing programs.
A wind turbine can reduce both power bills and your carbon footprint, but only if the turbine tower is properly sited. Wind speeds aren't enough. Space, surrounding wind barriers and zoning restrictions must also be considered.