Concerns About Wind Power in an Urban Enviroment

(Aside: Thanks to everyone who has e-mailed me about Science Debate 2008. I am planning on writing a few posts about how this years crop of politicians have performed on issues relating to the environment in October. Until then, you can stop e-mailing me about this :-).)

Avid reader, master strategist and all around great guy Chris John noted this concern about implementing wind power in an urban environment:

If an art exhibit (Olaf Eliasson's [sp] waterfalls) under the Brooklyn Bridge almost killed two kayakers, I dread to think of the mess we're going to have to clean up from wind turbines.

So lets take a few minutes to address wind power, and to think about how well suited it would be for a major urban region like New York City.

A couple of years ago I was lucky enough to win the Evan R. Liblit Scholarship. I was honored to be chosen as the Evan R. Liblit Scholar, since Mr. Liblit was an environmental hero, championing the cause of recycling and responsible waste management on Long Island during the 1980’s and 1990’s. (People are so passionate about Evan Liblit, that they are even willing to row the length of the Yukon River to raise awareness and money). As part of the Scholarship I was to attend the New York State Solid Waste and Recycling Conference in Lake George. Admittedly, I wasn’t particularly excited about this – who wanted to spend a week learning about garbage? But my talk was well received, which was great and I got to see a presentation session on Wind Power in New York State, the content of which has stuck with me ever since.

As it turns out, wind power is becoming a big business in many parts of New York State, especially those regions that abut the Great Lakes. The regions downwind of the Great Lakes are (as we discussed before) in a region with great wind power potential, and also are suffering from a still stagnant economy that began its decline in the late 1980’s. As such many municipalities are investigating whether allowing utility companies to construct wind turbines on farmland and other open terrain would be beneficial to the communities. I can’t recall this with much certainty, but I do recall someone citing at the conference the example of a small town that had reduced its school and property taxes to zero by contracting with a major utility.

To me, one of the most surprising aspects of the wind power craze in Central and Western New York State, was the degree to which lawyers needed to be involved in the process. Here I will try to speak as simply as possible to avoid displaying my legal ignorance (much like Sarah Palin should avoid speaking in public about polar bears, global warming and ANWAR – ZING!). Small rural municipalities were very much so dependant upon two firms (one in Albany one in Buffalo) to draft complicated lease agreements with utilities as well as to craft appropriate zoning regulation that protected the health and welfare of residents along with allowing for economically reasonable utilization of wind energy. This process is much more involved than you think, due to the impacts of ice throw and noise pollution generated by wind turbines (actually it is so complicated that there is a legal blog dedicated to issues regarding wind power).

Ice Throw

Ice throw occurs when wind turbine blades become coated in ice, generally from freezing rain or from freezing fog. As winds pick up after the storm, the blades begin to rotate and in the process the ice that has accumulated on the blade can be thrown over large distances. The figure to the right, taken from this non-peered reviewed source, shows the distance ice can be hurled. Along the ordinate (x-axis) is shown the width of the turbine blades in meters. The y-axis shows the distance that ice chunks have been thrown. The color of the dots show the mass of the hurled ice chunks. Smaller chunks of ice have been shown to be thrown lengths in excess of three football fields. Larger chunks of ice, coming in at about 1kg or 2.2 lbs have been shown to be thrown 25m! Well take those results with a grain of salt, since they don’t come from a peer reviewed source, but none the less it is evident that wind turbines cannot be sited in densely populated regions, or even in regions with large amounts of infrastructure. It doesn’t need to be said, but obviously chunks of ice flying off of 50 story buildings in Manhattan would probably be frowned upon by local residents.

It should be noted that by my recollection, none of the speakers at the conference considered ice throw to be a major issue. They noted that technology was improving, reducing the capacity of ice to be thrown and that the amount of ice accumulation was relatively small in general and limited to short periods of the year. They also pointed out the lack of observed injuries related to ice throw, suggesting that either this is not a serious issue or that people have done a good job citing turbines.

Noise Pollution
A second major concern that requires the attention of zoners, is that of noise generation. Turbines when operational generate a low frequency humming noise. Although not altogether an unpleasant sound, the volume (which gets higher as the turbines speed up) accumulated over time can injure local residents long term hearing.

Here is a video of a large industrial wind farm, documenting the noise that the giant turbines make:



The amount of noise will vary based on the design of each turbine, the wind speed and local topography. Each community needs to assess how much noise each turbine in their town is expected to put out, and make zoning regulations that make sense for local resident’s health. In the case of New York City, it is unclear whether or not a wind turbine would produce noise in excess of the current noise levels. Massive wind turbines, like those shown on the above video are also not possible in an urban environment. One imagines that a smaller turbine built for rooftop use would have a much smaller noise impact.

Aesthetic impacts
The visual presence of wind turbines is thought to have a potential negative aesthetic impact. This is true in many pristine environments, but in other environments some folks actually enjoy the way the wind turbines look. I wish I had a reference to back this up, but I heard once that in Europe property values of locations with wind turbines.

In the case of the Long Island Windpark, concerns over property value were paramount. Additionally folks were very worried about the impact of wind turbines on the view from regional beaches and tourism.

Bird deaths
To be frank, I think that this issue is overstated. The number of birds killed by feral cats at Stony Brook University outnumbers the total number of birds killed by wind turbines in all of New York State I would guess. This issue seems to be something of an “ecco-myth” and probably stems back to antiquated technology. Some new wind turbines come equipped with “whistles” that emit sound on a wavelength that birds can hear (humans however cannot hear the sound) and find annoying.

Birds have a large number of threats to their well being to be sure, high tension wires, high rise buildings, automobiles, domesticated invasive species – I’m not so sure that wind turbines are of the order of impacts as the previously listed problems.

Yikes this post is getting long, probably past the point that anyone is still reading. So let me conclude with a wildcard. Everything we have been discussing so far has pertained to the traditional wind turbine. Colossal, gigantic, tall, massive – these are all adjectives that could be used to describe the turbines. These are not the sorts of turbines that would be practical in New York City.

Rohit Aggarwala, the director of the city’s Office of Long-Term Planning and Sustainability, said that turbines on buildings would likely be much smaller than offshore ones. Several companies are experimenting with models that look like eggbeaters, which the Bloomberg administration says could be integrated into the spires atop the city’s tall buildings. “”You can make them so small that people think they are part of the design,” Mr. Aggarwala said. “If rooftop wind can make it anywhere, this is a great city,” he said. “We have a lot of tall buildings.”

Such new turbines would have to be designed to not produce any icethrow, and regardless of the size of the particles or how far they are thrown, ice chunks falling from sky scrapers would not be acceptable. Noise concerns must be taken into account, but I’m not entirely confident that wind turbines would be appreciably louder than air conditioner units currently housed on many rooftops, nor would they be louder than the ambient city noise levels. Bird kill in New York City may be a serious problem as many birds congregate on city rooftops. Furthermore, birds in New York City are notoriously stupid and their termination may be a blessing in disguise…just kidding.