Living with Wind Turbines and Coal Exhaust
We can't look at all of the externalities of all of the different energy sources. But, here are a few observations on wind, and then on coal.
The National Research Council (US) in 2007 looked at Environmental Impacts of Wind-Energy Projects (Washington, DC). Summarizing other research on p. 51 of the report, for the U.S.:
Collisions with buildings kill 97 to 976 million birds annually; collisions with high-tension lines kill at least 130 million birds, perhaps more than one billion; collisions with communications towers kill between 4 and 5 million based on 'conservative estimates,' but could be as high as 50 million; cars may kill 80 million birds per year; and collisions with wind turbines killed an estimated at 20,000 to 37,000 birds per year in 2003, with all but 9,200 of those deaths occurring in California. Toxic chemicals, including pesticides, kill more than 72 million birds each year, while domestic cats are estimated to kill hundreds of millions of songbirds and other species each year.
A recent study for Canada (Calvert, A.M., and 6 others, 2013, A synthesis of human-related avian mortality in Canada, Avian Conservation and Ecology 8(2), article 11) found the following rates of bird deaths from the listed causes (the mid-range estimates are shown here, with some ''lumping'' - for example, the study separates feral cats from domestic cats, but we added them together here as "cats," and made some other similar combinations; note that 'buildings' involves birds flying into buildings, not buildings falling on birds):
- Cats: 196 million
- Power lines: 28 million
- Transportation (cars and trucks): 14 million
- Hunting: 5 million
- Pesticides: 3 million
- Buildings: 2.5 million
- Hay cutting: 2.2 million
- Forestry: 1.4 million
- Communications towers: 0.2 million
- Mining: 0.2 million
- Hydroelectric reservoirs: 0.15 million
- Oil and gas: 0.025 million
- Fisheries: 0.023 million
- Wind energy: 0.017 million
Power lines might carry electricity from wind energy, but also might carry electricity made with oil and gas, or other sources.
Even increasing wind to generate 100% of our energy (something that is not envisioned) probably would leave wind turbines less dangerous to birds than some other human-caused conditions. And, again, considering the dangers of climate change to wildlife, and the potential to avoid climate change through construction of wind turbines, it is likely each wind-turbine built saves more birds than it kills (e.g., Sovacool, B.K., 2012, The avian and wildlife costs of fossil fuels and nuclear power, Journal of Integrative Environmental Sciences 9, 255-278).
Wind farms certainly make some noise, and block some views. So do many other things. Recently, much discussion has focused on 'infrasound', low-frequency noise from wind turbines. Astudy for the Environmental Protection Agency in South Australia (Evans, T., J. Cooper and V. Lenchine, 2013, (Infrasound levels near windfarms and in other environments) found similar infrasound levels at rural sites close to and far from wind farms, and generally higher levels in urban areas far removed from wind farms.
A fascinating psychological study also looked at this issue (Crichton, F., G. Dodd, G. Schmid, G. Gamble and K.J. Petrie, Can expectations produce symptoms from infrasound associated with wind turbines? Health Psychology, March 11, 2013, doi: 10.1037/a0031760). The people in the study ('subjects') expected to be exposed to infrasound, but then some were exposed to infrasound and some weren't. The subjects were shown either materials quoting scientists that infrasound at such levels is not a health issue, or first-person accounts of people claiming health impacts from wind-farm infrasound. Subjects exposed to the stories of wind-farm health impacts reported that the infrasound gave them similar symptoms, whereas subjects exposed to the scientists did not report such symptoms, with no differences related to whether the subjects were or were not exposed to infrasound. Thus, this study found that infrasound did not cause people to report health problems, but stories about the dangers of infrasound did.
There clearly is much more literature on this topic than these few examples. But, we believe that these examples tell representative stories; there are externalities of wind, but they are far smaller than for most alternatives.
Here is one more possibly relevant story on externalities of wind. As described in his book Earth: The Operators' Manual, when Dr. Alley spent a few months on Cape Cod in the autumn of 2009, wind power was in the news extensively. Dr. Alley did not conduct any formal studies, but he read the local newspaper every day, listened to local radio and TV, and talked to people. Anecdotally, wind power being used to clean up polluted local groundwater, or to lower local taxes, was primarily viewed as being highly beneficial, with few dissenting voices. However, wind power that was planned to be built offshore of the Cape, in the view of the people living there, for the primary purpose of shipping energy off-Cape, and with the people expecting little or no direct benefits, was primarily viewed negatively. When the people expected to benefit from the wind power, most of them were not worried about the externalities; when the people did not expect to benefit, many more worries were expressed about externalities.
The relevant scholarship on coal tends to show much greater externalities than for wind or other renewables. Some people who rely heavily on coal are still quite willing to experience the externalities, but overall the economic impacts of the illnesses caused by the coal can be quite large. The studies discussed below are all for the USA. Note, however, that because the regulatory situation has been changing, and natural gas has been replacing some older coal plants, the situation may be somewhat better now than when the studies cited below were conducted.
One study (Epstein, P.R. and 11 others, 2011, Full cost accounting for the life cycle of coal, Annals of the New York Academy of Sciences 1219, 73-98) estimated that a subset of the externalities from coal, such as illnesses from airborne particles and mercury, costs society at least as much as the coal-fired electricity costs customers, and probably at least twice as much (climate-change costs were estimated as less than 20% of this total). Thus, this study found that for each dollar spent on coal-fired electricity by a customer, causing the power company to mine the coal and generate the electricity, society loses more than another dollar because of health impacts and other problems.
This result is supported by the study of Muller et al. (Muller, N.Z., R. Mendelsohn and W. Nordhaus, 2011, Environmental accounting for pollution in the United States economy, American Economic Review 101, 1649-1675), who found that for the economy as a whole, '. . .coal-fired power plants have air pollution damages larger than their value added. . . damages range from 0.8 to 5.6 times value added.' Again, climate-change costs are small compared to other costs of coal, and again, this study did not assess all of the negative externalities of coal-fired electricity.
Levy et al. (Levy, J.I., L.K. Baxter and J. Schwartz, 2009, Uncertainty and variability in health-related damages from coal-fired power plants in the United States, Risk Analysis 29, 1000-1014) looked at damages from particulate air pollution (including particles formed in the atmosphere from sulfur dioxide and nitrogen oxide emissions), for 407 coal-fired power plants in 1999, considering both emissions from each plant and how many people were exposed because they lived close by. This study found that the health impacts from just the particulates exceeded the cost of the electricity for most of the plants. With a typical retail cost of electricity of about $0.09 per kilowatt-hour, the negative externalities were estimated as ranging from $0.02 to $1.57 per kilowatt-hour for the different plants. Clearly, it is possible to build coal-fired power plants with much lower impacts than from some operating plants, and the very high costs from some plants do not prove that all coal-fired power is 'bad'. But, if actions are taken to reduce power generated from such plants and replace it with almost any other source, there are likely to be large benefits to society. And, while cleaner coal plants would cause lower externalities than the older, dirtier ones, most other alternatives would lower externalities even more.
You can probably find literature with smaller estimates of damages. However, the weight of the literature does indicate that fossil-fuel externalities are notable, and especially in the case of coal are quite high compared to other energy sources, including traditional oil and natural gas. (Tar sands are being developed now, and in some ways may turn out to have certain similarities to coal. This will be an interesting story to follow to get clearer answers.)