Small Wind Turbine Zoning

Generally speaking when it comes to zoning for renewable energy systems the most common “complaint” is based purely on aesthetics – neighbors don’t want to see big aluminum panels on the roof, or a giant tower in the backyard. Solar of course is a little easier simply because there’s a wider range of options to integrate solar into buildings – case in point, my home: flat roof, thin film flexible panels that hug the roof, have an ultra low profile and can in no way be seen by anyone on the street. Wind turbines on the other hand are a little different, yes, they work best when they are out in the open, and they are typically on a pole at least 30 feet high. While I agree, in part, that we should probably restrict large turbines in dense suburban areas, generally banning them clearly is not an option.

I’ve had a number of interesting conversations with clients, city officials and neighborhood associations around this idea. Granted in Florida, most people aren’t thinking about small wind, but up in New England, that’s a different story – clients want wind. So the purpose of this hub is to offer some advice and direction for individuals and municipalities to follow regarding what has been tried in cities around the country that already have wind zoning.

There are very few municipalities out there that have zoning rules specific to small wind turbines, which means that if you, as a property owner, want to install a turbine you’re going to need a variance / conditional use permit - a process which can sometimes feel akin to negotiating the Treaty of Versailles and can cost quite a bit of money.

For those who are interested there is some good legal precedent made by the State of California (Assembly Bill 1207 passed in 2001) for small wind and The American Wind Energy Association (awea.org) has some great information on zoning including links to other state and municipal zoning ordinances. But for those who think ritual suicide a more palatable option than reading municipal code here’s a crash course in what the issues are.

Height Restrictions – Small wind turbines start at 30 feet and go up from there, some poles reaching as high as 120 feet, but on average about 45 to 50 feet. Certain counties have stated a minimum lot size of 1 acre, others have said the turbine must not be placed anywhere that could endanger another persons property if it were to fall – if you have a 30 foot turbine that would mean you would need minimum 60 by 60 area free from your neighbors lot, that’s a 3,600 square foot area free from anything. These pointers kind of help define height limits and setback requirements.

The second issue that should be addressed is how much power can you generate - an odd thought, but necessary - it’s in all our best interests not to have mega-mini wind farms popping up everywhere. Farmers in the midwest lease out their land for large turbines to create wind farms. I think we can all agree that we don’t want massive un-regulated urban wind farms littering our communities. Limiting the number of turbines won’t really do it, think about large farms with lots of acreage, or schools that might want a couple, two or three or four connected to different buildings, vineyards in California are perfect examples of properties that would benefit greatly from a collection of small turbines, vines are low to the ground (not a lot of obstruction), energy use is high due to irrigation needs, wind is steady, depending upon the topography of the land limiting them to one turbine wouldn’t be the best solution (more turbines, smoother more regular power generation). What’s probably a better bet is to limit rated capacity – the idea here is you want to prevent property owners from setting up a sideline business where they’re selling power to the utility, a little excess is okay and even beneficial to the grid. There needs to be a division between power generation for personal use and commercial power generation. This is all pretty easy to regulate, because we all get power bills from our utility and they all post our kilowatt hour usage. A 3,000 sq ft home that wants to install a 1.5 Mw turbine is clearly selling excess capacity to the grid. A simple requirement should be a wind study for at least a month provided with the building permit application / plans, plus average annual kilowatt hour consumption from the electric bills – residential properties can’t generate over 150% their annual consumption – as a rule of thumb the average single family home in the US would be well matched with a 5 kilowatt turbine. If you have a larger house, larger electric bill and a larger plot of land you can either do multiple 5 kw turbines or step up to a 10 kw or 20 kw. Commercial and industrial properties can of course do more, once again based upon their needs and the size of their land.

The third item to consider is noise levels. Turbine’s these days are pretty quite, but they do make a little noise. In the State of California ordinance they capped the noise level on a typical day not to exceed 60 decibel’s at the property line of your nearest neighbor – 60 decibel’s is roughly equivalent to the noise of an average conversation. In 2003 the National Renewable Energy Laboratory did an “Acoustics Test of Small Wind Turbines” (google it, in quotes) and the basic finding was that based upon a distance equal to the height of the turbine on the low end of the scale the turbines produced about 45dB, average about 60dB and at the highest, in high winds not more than 85dB.

So, if you notice the correlation, it’s probably not inappropriate to require the turbines placement on the property to be equal to the height of the turbine relative to the distance from the neighbors property line – 35 foot turbine, 35 feet away from property line. On a practical level that’s pretty much going to limit installations to people who have an acre or more.

Municipalities, do a little research and pass a wind zoning ordinance. To property owners and concerned citizens, help get this started. Talk to your city officials and get a wind zoning ordinance passed, go to a commission or town hall meeting, raise your hand and get the dialogue going. If you’ve got a nice chunk of land, do a wind study and apply for a permit, if you don’t have a zoning ordinance, hopefully I’ve put you in the direction of some good guidelines to help you on your way.