In Michigan, wind generation has grown rapidly over the past decade and is expected to continue growing for the foreseeable future. DTE and Consumers Energy, have indicated that they intend build additional wind generation capacity over the next few years.[*] Despite public interest and rapid recent growth, wind provided less than 5% of Michigan’s net electricity generation in 2018.
A benefit associated with using wind power is that it provides an alternate form of electricity generation and helps to diversify the overall electrical grid. Additionally, wind turbines do not emit greenhouse gases or other pollutants into the atmosphere at the point of electricity production, that is, without considering the dispatchable backup generation needed due to the wind’s intermittency. The price to install industrial wind has come down over the past decade, if not including the costs imposed on the rest of the electric grid for the necessary backup generation and increased transmission infrastructure. The 2019 Lazard’s Levelized Cost of Energy Analysis 13.0 Report estimates the levelized cost of energy and lists the current unsubsidized price of wind between $28 and $54 per MWh.
Some challenges associated with wind generation include the substantial financial and policy support it receives in the form of government subsidies and mandates that require some energy to be produced by wind.[†] Wind also is hampered by the fact that it is not a dispatchable resource. Wind turbines can only produce power when the wind is blowing within a specific range of speeds. This means they cannot be relied on to produce electricity at any one specific moment.
In Michigan, wind has a 36% annual capacity factor, meaning that it produces electricity in unpredictable surges 36% of the time, which roughly equates to 8.6 hours per day. The remainder of the time, wind must be “firmed up,” where electricity is provided by other energy sources, like natural gas internal combustion and simple-cycle turbines, or the still scarce and very expensive supply of utility-scale batteries.
Wind developments also can have substantial impacts on bird and bat populations. For example, a 2013 Wildlife Society Bulletin study, using a total installed wind capacity of 51.6 GW, estimated 888,000 bat fatalities and 573,000 bird fatalities annually. But the American Wind Energy Association estimated that there was about double that amount — over 100 GW — of installed wind capacity in the U.S. at the end of the third quarter of 2019. Additionally, while they admit that they only have “very rough” estimates, the American Bird Conservancy claims that collisions and electrocutions associated with wind infrastructure — power lines and towers — kills between 8 million to 57 million birds each year in the U.S. The wind industry defends itself by pointing out that they are using updated technologies and timing turbine operations to reduce collisions. They also note that collisions with windows and automobiles, and predation by feral and domestic cats kills more birds each year than the wind industry. The birds that are killed by cats, home windows, etc. tend to be widely distributed and non-threatened species. The U.S. Fish and Wildlife Service reports that while wind turbines do have a substantial impact on over 200 species of domestic passerine (perching) birds, they also have a significant impact on many threatened and endangered species of large raptors — hawks, eagles and falcons, which are not impacted by homes, and cats.
As they are designed to gather a very diffuse energy source, wind developments also necessarily take up a very large amount of area. There is no one specific, established measure of area required for a single turbine, or that describes the MW per acre that a wind generation project produces. This is because there are a variety of patterns in which wind turbines can be installed on a variety of different types of terrain. However, the National Renewable Energy Laboratories published a study in 2009 that analyzed the land-use requirements of wind power plants and suggested large wind power installations (more than 20 MW) had a general density of 30-138 acres per MW. A 2017 Strata research paper arrived at a similar estimate, noting that wind requires just over 70 acres per MW. In comparison, nuclear, natural gas, and coal generation each required just over 12 acres per MW. Solar required 43.5 acres per MW and hydroelectric required over 315 acres per MW.
[†]DTE plans to generate 50% of its energy from a mix of renewable sources, as well as energy waste reduction and demand response by 2030, with the majority of this new clean energy production coming from wind and solar. Consumers Energy plans to spend almost $5 billion from 2010 to 2024 on new production of renewable energy, most of which will come from wind. Jason Hayes, “Public Comments by Jason Hayes, director of environmental policy at the Mackinac Center for Public Policy,” Michigan Public Service Case #U-20471, File #U-20471-0455, Sept. 30, 2019, https://perma.cc/LF7E-NCZ2.
[†]If these subsidies and mandates were to be revoked, the competitiveness of wind within the entire energy market could be significantly reduced.