The Climate in Emergency

A weekly blog on science, news, and ideas related to climate change

Looking at Wind Power

Leave a comment

Wind power has been in the news in my area lately, with the pros and cons of specific projects being argued in the papers. As often happens, these stories have raised questions for me, and inspired me to do a deep dive into the subject. Here goes.

In the News….

Remember Martin O’Malley? He ran for the Democratic nomination for president last cycle. I suspect he will try again and could well be president someday. He is still very much a rising politician. In any case, he used to be the governor of Maryland, my state, and as such racked up a very impressive environmental record. He takes climate science very seriously. And one of the things he did was to champion the Maryland Offshore Wind Energy Act of 2013, which incentivizes wind power in various ways. Various renewable energy companies have been attempting to take advantage of the opportunity. This spring, two companies received regulatory approval to build wind farms near Ocean City. Combined, the project would be only the second US offshore wind farm, and by far the largest.

There are a lot of issues involved in this project. Besides the hoped-for emissions reductions, there is the political value of getting a major renewable power facility up and running, and the economic value of a big manufacturing project. The turbines themselves would be made here in Maryland.

But not all issues are positive. There is concern that wind turbines can disturb or kill wildlife, and there are worries that wind power might not be as “green” as it’s made out to be. Finally, there are aesthetic concerns. Though I, personally, find wind turbines kind of cool-looking, plenty of people don’t, and the project has been pushed farther and farther offshore in order to minimize its visibility from the beach–tourism being a major source of Ocean City’s revenue. I have seen a photograph doctored to represent how the current project will look from shore when completed (it’s included in one of the articles I’ve linked to), and honestly I’m not sure whether the specks visible on the horizon are wind turbines or dust on my screen. But yet some in Ocean City remain concerned.

In comes Dr. Andy Harris, Eastern Maryland’s delegate to the US House of Representatives (and yes, he’s a medical doctor, too).

Representative Harris has sponsored an amendment (an amendment to what, I’m not sure) that would block Federal funding for site assessments for wind turbines within 25 nautical miles of the coast. This move, if approved, would effectively block at least one, possibly both of the planned projects. Not only would moving the wind farms further out take time that neither company has budgeted for, but the farther offshore a wind farm is, the more expensive it becomes. At a certain point, a project simply stops making good business sense. Representative Harris says he supports the wind farm, but is simply concerned about the business interests of his Ocean City constituents–but it’s worth noting that his overall environmental record is terrible. In general, the wind farms have a lot of public support (though less in Ocean City).

Pros and Cons of Wind

Politics aside, how do wind farms actually stand up, environmentally? The environmental cost of a wind turbine is not zero, for although there are no carbon emissions during operation, the same cannot be said for manufacture,transportation to the site, routine maintenance, and so forth. So, what is that cost? The answer depends largely on which data you include in your analysis and how exactly you ask your questions–which is one reason why it’s possible to find wildly differing conclusions on the subject, all apparently “fact-based.” With that in mind, I focused as much as possible on more scholarly sources, people who did not seem to be arguing for a specific preferred option. But it is possible I missed something. As always, this post is meant as the beginning of your research on a subject, not the final word.

Wind at Home

Most of the figures I looked at related to the large turbines used for utilities-scale generation. After all, my hunt for information was started by a proposed wind farm. It’s worth noting, though, that there are other forms of wind generation. Some turbines are small, designed for home use. Some are even portable. I expected that small-scale turbines would have a better environmental profile than large ones, partly because they just appeal to my taste (I WANT them to be better!), and partly because the absolute environmental cost of a small unit is obviously so much smaller. But the important thing to consider is not the absolute cost but the cost-benefit ratio, and according to one study, home-based wind turbines don’t always have a good ratio.

The way cost-benefit ratios are expressed in this context is payback time–how long does it take for the carbon emissions saved by using a turbine to equal the amount of greenhouse gas emitted during construction, installation, maintenance, and decommissioning of that turbine? If the payback time is shorter than the working life of the turbine, its net impact is carbon-negative (that’s good). If it’s longer, that’s a carbon-positive impact, meaning a net increase of emissions (bad).

Three figures go into determining how long payback time is for a given system: the total environmental cost of the turbine; how much electricity the turbine generates; and the environmental cost of whatever form of electricity generation the turbine replaces. Payback times in general are expected to lengthen in the future as the electricity grid, as a whole, becomes less carbon-intensive.  For micro-wind, both carbon cost and electricity generation can vary widely.

The study I mentioned analyzed several different turbines at several different locations. The “greenest” turbines were responsible for less than 200kg (441 pounds)of carbon dioxide—not good, exactly, but many people emit as much every day simply by commuting to work in the morning. Others topped 1,500kg (3307 pounds).

Meanwhile micro-turbines sited in windy areas could generate a respectable 40% of a typical home’s energy use, but turbines in large cities, where buildings block or dissipate a lot of the wind through turbulence, only generated about 2%.

So, if you live in a windy area and your house is relatively isolated, you can achieve payback in a year or so, if you choose a micro-turbine model with a low carbon cost. But in other circumstances, payback might never happen. You’re better off buying your electricity from the grid.

Wind and Birds

One of the most concerning charges against wind power is that turbines kill birds and bats and otherwise harm wildlife. Of course, so does climate change harm wildlife. As much as I don’t want anything to harm animals, a fair judgment depends on a realistic comparison.  Large number of birds are at risk of extinction due to climate change, so if wind power can slow climate change, then the birds come out ahead, unless the death toll from turbines is truly horrific.

According to a document by the Union of Concerned Scientists, the death toll from turbines is not horrific—no bird or bat populations are at risk from turbines. The number of individuals killed can be dramatically reduced by careful siting and other steps, such as locking the turbine blades when the wind is low. Bats are more active in calmer air, when turbines don’t generate much electricity anyway. Offshore turbines can negatively affect marine life, but can also create artificial reefs that help marine life, so again, proper siting is critical.

Carbon Cost for Large-Scale Wind

For a detailed look at both the environmental and financial costs of wind, check here. The article also addressed several specific common criticisms in quick detail. At present, payback time for utility-scale installations is one to two years, unless sited somewhere, such as peatlands, where the disturbance of development itself has a high carbon cost. A graph comparing the per-kilowatt hour cost of various forms of energy makes it difficult to compare the different renewables–because all of them are so low as to be indistinguishable from zero next to fossil fuel generation. Not that their emissions are zero, but it’s like trying to create a graph comparing the body weights of three different kinds of songbird, a mouse, a sheep, and a cow.

Does wind reduce carbon emissions as compared to fossil fuel? You bet.

At least wind reduces carbon if it replaces other forms of energy generation instead of adding to them. While the article does address the issue of standby generation (some people have charged that because wind doesn’t always blow, wind power requires the use of other forms of generation. The article acknowledges the point, but says the carbon emissions still end up going down), it does not address the issue of overall demand caps.

Let’s say we us X amount of electricity generated by fossil fuel. So if we bring X amount of non-fossil fueled generation online, will that mean the end of fossil fueled electricity? Or will the public just decide to use twice as much electricity?

The answer to that puzzle lies somewhere in a complex tangle of economics and policy. I am not prepared to answer it, but it must be answered. My guess is that this is a problem the free market cannot solve by itself, even assisted by subsidies. We will eventually need a cap on either total electricity use or total fossil fuel use in order to get off fossil fuel.

And get off fossil fuel we must.


Author: Caroline Ailanthus

I am a creative science writer. That is, most of my writing is creative rather than technical, but my topic is usually science. I enjoy explaining things and exploring ideas. I have one published novel and another on the way. I have a master's degree in Conservation Biology and I work full-time as a writer.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s