Picture was taken at the Michigan Wind 1 Farm up in Huron County Michigan. This farm consists of 46 GE 1.5 MW turbines and is owned and operated by the John Deere Renewables LLC.
We have been harvesting the wind for energy for thousands of years, from sailing ships, to windmills, the next logical step was to use this seemingly endless source to generate electricity, even if it isn’t very predictable. For those who might not be aware of it, wind is basically another form of solar energy. Heat from the sun warms the air which becomes less dense and rises. Air that had risen will be displaced by more rising air, cool, and sink back down. This rising and sinking forms a convection current, and it is this movement of air that creates wind. Now, the trick to being able to convert wind into electricity is to be able to change the linear motion of air into rotational motion that can be used to turn a generator.
To be fair to my readers I must say that I am a little partial to the idea of wind energy, especially when considering the aesthetics. Having visited Michigan Wind 1, I think these tall spinning structures are very cool looking. However, like all sources, this is not a perfect solution to our energy needs, and I may represent a small minority who actually like the way these new wind turbines look. Many also complain that they kill birds and bats, and can cause health issues for those living within close proximity.
As for the visual impact of a wind farm on the landscape, this is a purely subjective criterion and would be an issue that individual communities would have to address before a wind farm is installed. I am not trying to minimize people’s feelings about the visual impact a wind farm would have, but this may be an issue for some communities and not for others. I am sure that someone in Martha's Vineyard will be less willing to see a wind farm installed off the coast.
Common complaints raised by those who are not fans of this new technology sometimes refer to these machines as bird and bat "cuisinarts." I have done some investigation into these claims to see where this data is derived from and how accurate these claims are. It turns out that this complaint is based on bird mortality rates from a few studies at the Altamont Pass Wind Farm near San Francisco California in the 1980s. Numerous factors, including the design of the turbines, the towers, and the location contribute to the high mortality rate of raptors, but this is not the norm. More recent studies at newer generating sites that have larger turbines and more current designs have an extremely low mortality rate, especially when compared to bird deaths by other human activities. A commonly referenced study is one written by Robert W. Howe, William Evans, and Amy T. Wolf in 2002 covering a two year period between 1999-2001, and was focused on 31 commercial turbines in Wisconsin. Their finds suggest that 1.25 birds are killed annually by each tower which was close to the national average of 2.19 birds per turbine. When compared to how many birds are killed by cars, buildings (100million - 1 billion/yrs, the studies are on going), communication towers, feral cats (estimated to be at least 8 million/yr in Wisconsin alone), electrical transmission wires (estimated at 130-174 million per year), and pesticides (69 million per year are killed directly, an unknown number indirectly); these numbers are extremely low. The same was found to be true for bats as well. Though some bats do die, this is has been attributed to migrating bats that are thought to fly without using their famous sonar in order to conserve energy for the migration.
Unfortunately, it does seem that wind turbines in close proximity to a residence can induce certain health affects, usually related to lack of sleep. Dr. Nina Pierpoint, an adamant opponent to wind technology has written a book, and has a web site detailing an illness she has termed “Wind Turbine Syndrome.” I cannot vouch for her research, but I can say that there are documented complaints from residents who live near large wind farms. For instance, residents living near Michigan Wind 1 located up in the “thumb” of Michigan near the city of Ubly (where I have taken the pictures for this article) are not necessarily excited about having this farm in their back yards. In a Mlive article posted June 11th of 2009, journalist Jeff Kart talks to some residents who complain of sleepless nights and other disturbances due to the close proximity of the turbines. Dr. Pierpoints website has a number of articles from around the world indicating that this is not an isolated problem. Some have suggested that those who are complaining are doing so because they are not benefiting financially from having the turbines near by. At this point, its hard to say, but I will be looking into this more and more.
At this point I am not going to cover shadow flicker, which is the health affects brought on by the shadow cast by the blades as they spin. The health affects associated with shadow flicker, and just the spinning of the blades can cause vertigo, dizziness, nausea and the like.
One technological hurdle that needs to be addressed is due to the inconsistent nature of wind. The turbines cannot produce power on a predetermined schedule as with a conventional plant such as coal, nuclear or natural gas. Currently, the grid system cannot efficiently respond to the unpredictable quality of wind. A fundamental rule of the electrical grid system is that electricity must be used as it is generated and it cannot be stored. Given the large volumes of electricity that is consumed in the US, a wind farm can’t simply come online for a short irregular intervals because that would mean another generating facility would have to respond by ramping up or down to match the rate at which electricity is produced with the rate at which it is being used. This is one reason why our aging infrastructure needs to be updated is to make it “smarter” to blend the current large generating plants with these new renewable sources whose power is unpredictable.
Of course the benefits of wind power are that it is a renewable source of power that produces no greenhouse gases, harmful air pollutants or other long term waste. Also, wind has the potential to be very cheap. Depending on the location, the type of the turbine, and the wind speed, the cost of electrical generation from a wind farm can be competitive with current nonrenewable sources. The AWEA (American Wind Energy Association) has quoted the production of wind energy to be less than five cents per kilowatt hour when the Production Tax Credit is considered in the price. Compare this to 20-30 cents per kwh for solar, and this makes wind a very attractive renewable energy source. To give you a benchmark, coal can cost anywhere from 4-10 cents per kwh depending on location of plant and the source of the coal, but I think it is safe to assume that the cost per kilo watt hour is closer to 4 cents on average.
Advantages:
-Emits no air pollution while operating
- Relatively safe (in high wind speeds they can disintegrate violently)
-Cheap source of renewable energy
Disadvantages:
-Wind is not predictable
-To be affective, turbines need to be placed in specific locations
-May cause health affects to residents within 2 mile radius of large turbines
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