Proper Wind Turbine Siting

Careful wind turbine siting is an essential part of installing a wind power system. Keep these tips in mind while getting started.


| May 7, 2012



Wind-Rose

Wind Rose: This unique graph shows how often winds blow from various directions and the percent energy of the wind for various directions. The wider white bars represent the percent of total energy from different directions and the narrower, shaded bars illustrate the percent of total time from each of the sixteen different direction sectors.


ANIL RAO

Wind power is the fastest-growing source of energy in the world, and by the year 2020, it is projected to supply at least 12 percent of global electrical demand. Wind Power Basics (New Society Publishers, 2010) provides a clear understanding of wind and wind energy systems including turbines, towers, inverters, batteries, installation and more. Wind turbine siting is an integral part of installing a wind power system, and the following excerpt from Chapter 6, “Towers and Tower Installation,” will help you find the right location for your tower. 

Wind Turbine Siting

A wind turbine must be mounted in a good wind site, well above ground clutter in the strongest, smoothest winds. Wind site assessors begin the process of siting a wind turbine by determining the prevailing wind direction at a site. Although winds blow in different directions at different times of the year, or even within the same day, they arrive from one or two directions predominantly over the course of the year. In many places in North America, winds come predominantly from the southwest — thanks to the Coriolis effect. They often blow from the northwest in the winter.

To determine the predominant wind flow, ask the advice of farmers, who work outdoors and hence are familiar with wind patterns, or contact a local airport. They may be able to provide you with a wind rose, a graphical representation of wind direction. In a wind rose, the length of the spokes around the circle is an indication of how frequently the wind blows from a particular direction. The longer the line, the greater the frequency. In the wind rose in the Image Gallery, the winds blow predominantly from the southwest. A wind rose also indicates the percentage of total wind energy from each direction, which is very helpful. You can also find data on wind direction at NASA Surface Meteorology.

In an open site, with little ground clutter, a wind turbine can be located almost anywhere — so long as the entire rotor is mounted 30 feet above the tallest obstacle within a 500-foot radius and you’ve taken into account future tree growth, if trees are the tallest objects.

Unfortunately, very few of us live on ideal sites. There’s almost always some major obstacles.

For wind turbine siting, first determine the prevailing wind direction, then look for a location for the tower that’s upwind of major obstacles. Although winds will shift so that upwind temporarily becomes downwind, situating your wind turbine and tower this way will ensure that it can take advantage of the strongest prevailing winds.

john ledoux
5/26/2012 12:33:38 AM

Initial Cost and maintenance is prohibitive. Coal is the cheapest here in ND and MN, 11 cents KWH.


schteveo
5/25/2012 4:38:29 PM

I think the author / editors at MEN should have made more of a point about how not many of us will have 'optimum' locations. You can't run a magazine that touts self-sufficiency on a small place, then say, "...and ya' gotta have a 500' circle cleared to put up a windmill!" How do you rectify that stuff?


abbey bend
5/25/2012 2:14:38 PM

A point missed is possible code compliance on tall towers. A 140 foot tower will impact your house insurance and property line setbacks also. Most areas of the country will require a clear 280 foot diameter area, to install a tower that tall, also it will need to have a warning light for aircraft in many areas. Just something else to consider.


dennis ingham
5/25/2012 1:54:06 PM

Look into the "eggbeater" turbines. Windspire in Michigan makes some good ones.






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